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| Job No. 84056 07/09/88 Revision 15 INDEPENDENT ASSESSMENT PROGRAM CABLE TRAY SUPPORT DESIGN REVIEW ISSUES LIST FOR COMANCHE PEAK STEAM ELECTRIC STATION UNIT I GLENROSE, TEXAS Prepared for:
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| TU Electric Company Prepared by:
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| Cygna Energy Services 2121 North California Blvd., Suite 390 Walnut Creek, California 945%
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| 88071902C 880709 U LN ( ) i A PDR A
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| ADOCK 050C0445 PNU (
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| 11111!!I111111111111111ll11lll
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| 07/09/88 Revision 15 Page i CABLE TRAY SUPPORTS Review Issues List l
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| Table of Contents i Issue No. Issue Title Eags INTROL '.'CTION . . . . . . . . . . . . . . . . . . . . . . . . . . 1
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| : 1. Controlling Load Case for Design . . . . . . . . . . . . . . . . . . . 3
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| : 2. Seismic Response Combination Method ................ 6
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| : 3. Anchor Bolt Design ...... .................. 11
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| : 4. Design of Compression Members ................... 29 >
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| : 5. Vertical and Transverse Loading on Longitudinal Type Supports .... 37
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| : 6. Support Frame Dead and Inertial Loads . . . . . . . . . . . . . . . . 38 ,
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| : 7. Design of Angle Braces Neglecting Loading Eccentricity . . . . . . . . 42 :
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| : 8. Dynamic Amplification Factors (DAF), Tributary Tray Support Reactions ;
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| Missing Mass Effects . . . . . . . . . . . . . . . . . . . . . . . . . 50 i
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| : 9. Reduction in Channel Section Properties Due to Clamp Bolt Holes . . . 54 !
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| : 10. Sy: tem Concept ........................... 58 .
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| , 11. Validity c,f NASTRAN Models . . . . . . . . . . . . . . . . . . . . 63
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| : 12. Working Point Deviation Study . . . . . . . . . . . . . . . . . . . . 65 l
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| : 13. Reduced Spectral Accelerations . . . . . . . . . . . . . . . . . . . . 72 L i
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| : 14. Non-Conformance with AISC Specifications .............. 76 !
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| : 15. Member Substitution . . . . . . . . . . . . . . . . . . . . . . . . . 85 !
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| : 16. Weld Design and Specifications . . . . . . . . . . . . . . . . . . . . 88 TU Electric Comanche Peak Steam Electric Station d NJ( A Independent Assessment Program - All Phases Job No. 84056 Revision 15 111111111111111:!Il111!!I11111 TUE\84056\RIL-LMAN
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| 07/09/88 Revision 15 Page li 1 CABLE TRAY SUPPORTS Review Issues List
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| : 17. Embedded Plate Design . . . . . . . . . . . . . . . . . . . . . . . . 100
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| : 18. Cable Tray Clamps . . . . . . . . . . . . . . . . . . . . . . . . . . 104
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| : 19. FSAR Load Combinations ..................... . 117
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| : 20. Differences Between the Installation and the Design / Construction Drawings 1 without Appropriate Documentation . . . . . . . . . . . . . . . . . . 119 2L Design Con t rol . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 5
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| : 22. Design of Support No. 3136, Detail "5", Drawing 2323-S0905 ...... 153
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| : 23. Loading in STRESS Models . . . . . . . . . . . . . . . . . . . . . . 155
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| : 24. Design of Flexural Members ...... ....... ........ 159 i
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| : 25. Cable Tray Qualification . . . . . . . . . . . . . . . . . . . . . . . 173
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| : 26. Base Angle Design . . . . . . . . . . . . . . . . . . . . . . . . . . 183
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| : 27. Support Qualification by Similarity .......... ........ 186
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| : 28. Critical Support Configurations and loadings . . . . . . . . . . . . . . 190
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| : 29. Cumulative Effect of Review Issues . . . . . . . . . . . . . . . . . . 192 I i
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| : 30. Cable Tray Damping Values .......... ....... .... 195 j 3L Modeling of Boundary Conditions . . . . . . . . . . . . . . . . . . . 198 l
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| : 32. Conduits Attached to Cable Trays or Supports . . . . . . . . . . . . . 199 !
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| : 33. As-built Walkdown Procedures .. .......... ........ 204
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| : 34. System Analysis Methodologies .................... 2 11 TU Electric l r . ;d A Comanche Peak Steam Electric Station MLj6 Independent Assessment Program All Phases Job No. 84056 Revision 15 11111111111111111111ll11111111 TUE\S4056\RIL-LMAN
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| 07/09/88 l
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| Revision 15 Page 1 CABLE TRAY SUPPORTS Review Issues List INTRODUCTION This document summarizes the major issues which have arisen froni the review of the design and installation of the cable tray supports at Comanche Peak Steam Electric Station (CPSES) This review was conducted as a part of the Independent Assessment Program (IAP) performed by ygna Energy Services for TU Electric (formerly Texas Utilities Generating Company GCO)
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| 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 TU Electric; installation documents (e.g., assemb y 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.
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| The Cable Tray Support Review Issues List (RIL) is a tracking document which 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.
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| During the course of the IAP, an effort was made by the Project (Gibbs & Hill, Inc.,
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| TU 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 !
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| design change documents. In some cases, it was not possible to resolve certain issues in that manner, while in other cases Cygna did not accept the resolution provided by the Project.
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| 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 l which is entitled the "CPRT Program Plan and Issue-Specific Action Plans." Appendix C of the Plan, "Civil / 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. This activity, combined with the resolution of other safety-related design issues is a part of TU Electric's comprehensive Corrective Action Program (CAP),
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| TU Electric 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 and the CAP. Impell is responsible for the cable tray l systems located in the Unit 1 Safeguards and Reactor Bu!! dings, while Ebasco is responsible for the cable tray systems in the balance of Unit 1 and all of Unit 2.
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| TU Electric Comanche Peak Steam Electric Station 6.4 FJ t i Independent Assessment Program - All Phases ll111llllllllllllll111ll111lll Job No. 84056 Revision 15 TUE\84056\RIL-1. MAN
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| l 07/09/88 Revision 15 Page 2 CABLE TRAY SUPPORTS Review Issues List Both Impell and Ebasco developed a series of design criteria, work instructions and generic calculations to guide the evaluation effort and address each of the review issues. 'Ihese documents are provided as references to the ' Project Status Report - 1 Cable Tray and Cable Tray Hangers" Revision 0 (PSR)
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| Revision 15 of the RIL incorporates the responses provided in the PSR, in combination with the results of public meetings between Cygna and the CPSES Project and audits of Impell's and Ebasco's design validation program. This information has been used to update the status of each issue, to regroup several interrelated issues, and in some cases to add new issues pertaining to activities which were not incorporated in the original design effort for cable tray supports.
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| The resolution and closure of the issues has been an iterative process over an extended period of time. During this time, many of the design validation program documents have been revised one or more times in order to address Cygna's comments or for other reasons. The discussion of the resolution of several issues details the evolution of thesa documents. Though the references provided in the RIL are given as the revision number upon which issue closure is based, parts of the discussions may refer to earlier revisions of the same document.
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| At the time of issuance of Revision 15 of the RIL, all issues raised by Cygna have been addressed to Cygna's satisfaction and are closed.
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| TU Electnc Comanche Peak Steam Electric Station 6.8 L J 6 A Independent Assessment Program - All Phases i 111lll11111111111111l11!!1ll11 Job No. 84056 Revision 15 TUE\84056\RIL 1. MAN
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| 07/09/88 Revision 15 Page 3 CABLE TRAY SUPPORTS Review Issues List
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| : 1. Controlling Load Ce for Design
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| ==References:==
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| : 1. Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 5, Sheets 1620, Revision 5
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| : 2. Communications Report between P. Huang, S. Chang (Gibbs &
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| Hill) and J. Russ, W. Horstman (Cygna) dated November 13, 1984
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| : 3. Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 5, Sheets 17, Revision 1
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| : 4. CPSES FSAR, Sections 3.83 and 33.4
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| : 5. Ebasco Procedures SAG.CP4, "Seismic Design Criteria for Cable Tray Hangers for CPSES, Unit 1", Revision 6 and SAG.CP3, "Seismic Design Criteria for Cable Tray Hangers for CPSES, Unit 2", Revision 9
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| : 6. Ebasco Instruction, "General Instructions for Cable Tray Hanger Analysis for CPSES, Nos.1 and 2", Revision 11
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| : 7. Impell Instruction PI 02, "Dynamic Analyses of Cable Tray Systems", Revision 6
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| : 8. Impell Instruction PI-03, "Qualification of Cable Tray Supports", i Revision 5, with Addendum l l
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| : 9. Impell Instruction PI.07, "Design Verification of Base Plates, l Base Angles and Embedded Plates" Revision 4, with Addendum
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| : 10. ASME, "Boiler and Pressure Vessel Code", Section III, Subsection NF,1983 edition
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| : 11. Communications Report berveen S. Harrbn, J. Nandi (TU Electric); G. Ashley, B. Ramsey (Impell); R. Aicdru, SJ, Chen, P. Harrison, F. Hettinger (Ebas o); and N. Williams, W. Horstman, D. Leong, J. Russ, S. Tumminclu (Cygna) dated February 12, 1987
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| : 12. AISC, "Specifications for the Design, Fabrication and Erection of Structural Steel for Buildings," 7th edition TU Electric i Comanche Peak Steam Electric Station d(;6 d Independent Assessment Program - All Phases 1111tll11111111111111111111111 Job No. 84056 Revision 15 TUE\84056\RIL 1. MAN I
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| 07/09/88 Revision 15 Page 4 CABLE TRAY SUPPORTS Review Issues List
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| : 13. Impell Report 0210040/041, IM P 004, "Safety Margin Against Buckling using AISC Factored Allowables," Revision D.
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| : 14. Communications Report between S. Hamson (TU Electric), P.
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| Harrison (Ebasco), R. Kazcowski (Impell) and W. Horstman (Cygna), dated February 24,1988, 9:00 a.m.
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| : 15. Impell Calculation, M 12, "Qualification Procedure for Cable Tray Support Evaluations," Revision 6 Summary: 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 for 1/2 SSE (OBE) events. Based on this fact and a review of Section 3A4 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).
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| To validate this conclusion, the 60% increase in allowables must be liberally interpreted to be applicable to all support components 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.
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| Furthermore, for the design of structural steel, the 60% increase in allowables is acceptable for axial and strong-axis bending stresses in structural members. 'Ihe 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.
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| These limitations were not considered in the selection of the l governing seismic load case. !
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| l Response: Impell and Ebasco will perform a 100% reanalysis for both the OBE l and SSE loads assuming 4% and 7% critical damping, respectively, for the cable tray support systems (see Issue No. 30) Unfactored AISC TU Electric Comanche Peak Steam Electric Station AbJa A- Independent Assessment Program - All Phases 11lllll1111111ll1111111ll11111 Job No. 84056 Revision 15 TUE\84056\RIL-1. MAN
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| 07/09/88 l Revision 15 i l
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| Page 5 CABLE TRAY SUPPOR'I3 Review Imues List (Reference 12) allowables for structural steel are used for the OBE load case. For the SSE load case, the AISC allowables are increased ,
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| by 60%, with tensile and bending stresses limited to 0.9 Fy, shear l stresses to 0.5 Fy, and compression stresses to 0.9 Fer. i Cygna finds the use of unfactored AISC allowables acceptable for the l OBE load case and the use of a 60% increase acceptable for the SSE load case in most instances. However, Cygna has raised a concern of the allowable stremes used for components governed by non-ductile failure (i.e., compressive stresses governed by Euler buckling and .
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| bending stresses governed by lateral torsional buckling or local instability) under the SSE loading.
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| In response to this, Impell provided a data summary for the stress levels in 100 of the most highly stressed compression members. This data shows that the axial compressive stress generally provides a small contribution to the total mem xr interaction. 'Iherefore, the use of 0.9 Fcr is not significant for the member qualification. Impell has also demonstrated that lateral torsional buckling, (Issue No.14.B),
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| rarely governs the determination of the allowable bending stresses, so the criteria employed is acceptable.
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| Factors of safety for catalog components and Richmond Inserts) are established for(i.e., Hilti expansion anchors 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, respectively. A factor of safety of 3.0 is used for Richmond Inserts for both load cases. Cygna finds this approach acceptable.
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| Ebasco's implementation of this approach is discussed in Reference 5, !
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| Sections III.4 and IV. Sections 33.5 and 33.6 of Reference 7, Section '
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| 4.1.1 of Reference 8 and Sections 4.13 and 5.1 of Reference 9 discusses Impell's implementation.
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| l Status: Closed. j l
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| TU Electric Comanche Peak Steam Electric Station AIJ6 A Independent Mment Program - All Phases 11111lllllll111111lll111111111 Job No,84056 Revision 15 TUE\84056\RII 1. MAN
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| 07/09/88 Revision 15 '
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| Page 6 I CABLE TRAY SUPPORTS Review Issues List 2 Seismic Response Combination Method
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| ==References:==
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| L CPSES FSAR Section 3.7B.2.7
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| : 2. Gibbs & Hill Calculation, "Working Point Deviation Study," Binder No. 2323 SCS-215C, Sets 2 6
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| : 3. USNRC Regulatory Guide L92, Revision 1
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| : 4. N.H. Williams (Cygna) letter to J.B. George (TUGCO), "Cable Tray Support Design Review Questions" 84056.031, dated August 31, 1984
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| : 5. Gibbs & Hill Calculation in resp to IAP Phase 2 questions, Cygna Technical File 83090ES)
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| : 6. Ebasco Procedures SAG.CP4, "Scismic Design Criteria for Cable Tray Hangers for CPSES, Unit 1", Revision 6 and SAG.CP 3, "Scismic Design Criteria for Cable Tray Hangers for CPSES, Unit 2", Revision 9
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| : 7. Ebasco Instruction SAG.CP34, "General Instruction for Cable Tray Hanger Analyses for CPSES Nos. I and 2", Revision 11
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| : 8. Impell Instruction PI.02, "Dynamic Analysis of Cable Tray Systems", Revision 6 l
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| : 9. Communications Report between S. Harrison, J. Muffett (TU and N. Williams, S. Tumminelli, D. Leong, J. Russ and (W. Elec l Horstman (Cygna) dated March 6,1987
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| : 10. Impell Calculation M-49, "Seismic Load Combination Study", ,
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| Revision 2 '
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| 1L Impell Report 0210040/041 IM.P.002, "Seismic Load Combinations," Revision L
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| : 12. Communications Report between P. Harrison, J. Christoudias, P. K.
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| Hsuch (Ebasco); J. Russ, K. Parikh, W. Horstman (Cygna); and S.
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| Harrison (TU Electric) dated April 29,1987,10.15 a.m.
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| TU Electric Comanche Peak Steam Electric Station A NJk A Independent A-ment Program - All Phases ll1111lll1111ll1111lll11lll111 Job No. 84056 Revision 15 TUE\84056\RIL-LMAN
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| I 07/09/88 l Revision 15 I Page 7 CABLE TRAY SUPPORTS Review Issues List I I
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| : 13. Communications Report between G. Ashley (Impell); S. Harrison i
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| (TU Electric); and W. Horstman, D. I.cong, et al (Cygna) dated May 14,1987, 230 p.m.
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| : 14. Communications Report between G. Ashley and C. Aboujaoude (Impell); and, W. Horstman, D. Leong and B. Shakibnia (Cygna) dated May 15,1987,11.00 a.m.
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| : 15. Communications Report between B. Chen, J. Christandias, P.
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| Harrison, and J. Swanson (Ebasco); and W. Horstman and B. !
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| Shakibnia (Cygna) dated June 23,1987,1000 a.m.
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| : 16. Communications Report between S. Harrison (TU Electric); P.
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| Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al l (Cygna), dated September 24,1987, 220 p.m.
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| I
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| : 17. Communications Report between S. Harrison (TU Electric); P. ,
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| Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al l (Cygna), dated October 12,1987, 930 a.m.
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| : 18. Communications Report between S. Harrison (TU Electric); P. ,
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| Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al l (Cygna), dated November 17,1987, 3D0 p.m.
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| : 19. Communications Report between S. Harrison (TU Electric); P.
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| Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated November 19,1987, 920 a.m.
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| : 20. Communications Report between S. Harrison et al (TU Ele.:tric);
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| P. Harrison (Ebasco); G. Ashley et al (Impell); and J. Rust et al (Cygna), dated December 9,1987,1:30 p.m.
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| : 21. Communications Report between S. Harrison et al (*U Electric);
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| P. Harrison et al (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated December 10,1987, 920 a.m.
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| TU Electric nc Electric Station Program . All Phases TUEs84056\RII,1. MAN
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| l 07/09/88 Revision 15 Page 8 CABLE TRAY SUPPORTS Review Issues List Summary: A. Closely, Spaced Modes (10% Modal Combination) in Spectral Analysis 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.
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| 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.
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| Response: A. Ebexo, in Section IV3.C of Reference 6, and Impell, in Section 33.5 of Reference 8, indicate that the modal components of response from response spectrum analyses will be combined in accordance with USNRC Regulatory Guide 1.92 (Reference 3)
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| B. Ebasco, in Attachment F of Reference 7, and, Impell, in Sections 33.2,33.5 and 33.6 of Reference 8, indicate that the results of the dead weight analyses will be combined with the SRSS of the three directional components of the seismic analysis. The following combinations are used-DW + SEISMIC DW- SEISMIC Where: DW = dead y eight forces / stresses (signed)
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| SEISMIC = seismic forces / stresses (unsigned)
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| Cygna obser,ed the combinations noted above may not capture the critical loadings for the support members or the anchor bolts because the directional aspects of the 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 TU Electric Comanche Peak Steam Electric Station A NJ6 1 Independent A-ment Program - All Phases l 111111111111111111111111ll1111 Job No. M056 Revision 15 TUE\84056\RII 1. MAN 1
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| 07/09/88 Revision 15 Page 9 CABLE TRAY SUPPOR'I3 Review Issues List enveloped and appl!cd to the base plate models by hand to analyze for the critical inading case (Reference 12)
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| Subsequent to the above discussion, Cygna reviewed Ebasco's method of response combination and determined that Ebasco did combine at the stress level without consideration of sig or location of maximum bending stress (Reference 22). Ts method will capture the critical loading.
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| Impell provided an evaluation of the load combination methods used in their procedures in References 10 and 11. After reviewing these documents, Cygna noted that the conclusions were based on a comparison between a time history analysis and response sxctrum analysis of a number of sample cable tray systems. His comparison simply showed the conservatism inherent in the latter method with respect to the former method and did not address the load combination method.
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| Impell provided further analysis and a revised response. Impell stated that the response spectra and time histories used in the load combination comparison were conservative with respect to the target spectra and members with high stress interactions were chosen. Therefore, the comparison also demonstrated the conservatism of their load combination method (Reference 14).
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| Subsequent to the above discussions with Impell, Cygna reviewed Impell's revised response. As a result of the review, Cygna had many concerns which are described in detail in References 20 and 2L In response to Cygna concerns, Impell again revised their response to include an OBE analysis and regenerated the time history and response spectrum which were previously used.
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| Thus, the affected systems had more input energy. After making these revisions, Impell found that only one supprt was an outlier, i.e., that the interaction ratio based on Joads calculated using Impell's combination method differed from the interaction ratio based on loads from the time history analysis by greater than 0.02. This support was on a riser.
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| In summary, Impell stated that their calculation included 58 supports on 10 systems that covered many building elevations.
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| Impell further stated that given its unique geometry and loading, TU Electric Comanche Peak Steam Electric Station dbJt A Independent Aw= ment Program - All Phases ll111llll111111111111111111111Job No. 84056 Revision 15 TUE\84056\RII 1. MAN
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| 07/09/88 Revision 15 Page 10 CABLE TRAY SUPPORTS Review Issues List they had expected the riser su: port to be an outlier. Given the results of the analysis, Impell xlieved that an outlier could be predicted. Impell added that they did not expect similar outliers to occur in production analyses. The evaluatxm of support on risers is generally conservative since, when using the uniform response spectra method, the input spectra corresponds to a enbelope including the highest point of attachment to the building structure. They added that the load combination method is most sensitive to the ratio of dead weight to vertical seismic loading and since there was very little vertical amplification in the building, the ratio of gravity to vertical seismic accelerations is fairly consistent for all building elevations.
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| Cygna acknowledged that the systems that Impell had analyzed appeared to be representative of those in the plant and agreed with their conslusions regarding the vertical spectra. ;
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| Status: A. Closed.
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| B. Closed. Cygna will consider this issue as a part of their Cumulative Effects review. See Issue No. 29.
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| I 07/09/88 i Revision 15 Page 11 CABLE TRAY SUPPORTS Review Issues List
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| : 3. Anchor Bolt Design
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| ==References:==
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| : 1. Gibbs & Hill Calculation, "Evaluation of Detail 1, Single-Bolt Connection," Cygua Technical File 8405611.1.7 4)
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| : 2. Gibbs & Hill Calculation "Aux. Building Cable Tray Supports" Binder No. 2323-SCS 212C, Set 7, Sheet 4-11, Revision 0
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| : 3. Gibbs & Hill Calculations, "Justification of the Adequacy of 1" Richmond Inserts For the Effects of Prying Action," Cygna Technical File 84056111.?19
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| : 4. Brown & Root Procedure CEI 20, "Installation of Hilti Drilled-In Bolts" Revision 9
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| : 5. Hilti, Inc., "Architects & Engineers Anchor and Fastener Design Manual"
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| : 6. TUGCO SDAR CP-8012, "Reduced Allowable Loads for Hilti Kwik-bolts"
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| : 7. TUGCO Instructions CP-EI-4.0-49, "Evaluation of Thermo Lag Fire Barrier Material on Class 1E Electrical Raceways" Revision 1
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| : 8. USNRC Inspection Reports 50445/8114; 50446/81-14, dated October 27, 1981.
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| : 9. Communication Report between R.M. Kissinger (TUGCO); B.K. l Bhujang et al (Gibbs & Hill); and W.R. Horstman, et al (Cygna) dated October 10, 1984 1
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| : 10. N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO), "Cable ;
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| Tray / Conduit Support Review Questions" 84056.089, dated October 21, 1985
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| : 11. USNRC Office of Inspection and Enforcement, IE Bulletin No.
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| 79-02
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| : 12. American Concrete Institute, "Code Rec uirements for Nuclear Safety-Related Concrete Structures (AC" 349-76)"
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| l 07/09/88 Revision 15 Page 12 CABLE TRAY SUPPORTS Review Issues List
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| : 13. Gibbs & Hill Interoffice Memo, T.D. Hawkins to M. Strange, dated July 25,1964 l
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| : 14. Ebasco Procedures SAG.CP4, "Seismic Design Criteria for Cable Tray Hangers for CFSES Unit 1", Revision 6 and SAG.CP3, )
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| "Seismic Design Criteria for Cable Tray Hangers for CPSES, Unit 2", Revision 9 ,
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| : 15. Ebasco Instruction SAG.CP34, "General Instructions for Cable Tray Hanger Analysis for CPSES Nos.1 and 2", Revision 11 f
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| : 16. Ebasco Calculation, "Comanche Peak SES Cable Tray Hanger l Volume I", Book 3, "Prying Action Factors & Formulas for Evaluating Anchor Bolts", Revision 1 l
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| : 17. Ebasco Calculation, "Comanche Peak SES Cable Tray Hanger Volume I", Book 11, "Concrete Compressive Stresses under CTH I Anchorage Shims and Base Plates", Revision 0
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| : 18. Impell Instruction PI.07, "Design Verification of Base Plates, Base Angles and Embedded Plates", Revision 4
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| : 19. Impell Instruction PI-02, "Dynamic Analysis of Cable Tray Sys: ems", Revision 6
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| : 20. Impell Instruction PI-11, "Cable Tray System Analysis and Qualification Closcout", Revision 3
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| : 26. Impell Special Study No. 5.2, "Diamond Cored Bolt Holes",
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| Preliminary Issue
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| : 27. Gibbs & Hill Specification 232MS-30, "Structural Embedments",
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| Revision 2 1
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| 2& Communications Report between S. Harrison, R. Hooten, J. l Muffett, J. Redding (TU Electric); R. Alexandru, P. Harrison, E.
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| Odar, M. Strehlow, (Ebasco); G. Ashley, R. Grubb, B. Ramsey (Impell); and J. Russ, D. Leong, S. Tumminelli, W. Horstman, N. ;
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| Williams (Cygna), dated February 13,1987,11:30 a.m.
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| t TU Electric Comanche Peak Steam Electric Station d I. 6 A Independent Assessment Program - All Phases l111111111111111ll1111llll1111 Job No. 84056 Revision 15 TUE\84056\RIL-1. MAN i
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| i
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| 07/09/88 Revision 15 Page 13 CABLE TRAY SUPPORTS Review Issues List
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| : 29. 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
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| : 30. Ebasco Calculation, Tocunche Peak SES Cable Tray Hanger Volume 1", Book 12, 'UTH Anchorage Base Plate Flexibility Study", Revision 0 3L Impell Calculation M 04, "Base Angle Stiffness", Revision 4
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| : 32. J. Metcalf (Hilti) letter to J. Russ (Cygna), "Data Sheets for Pullout Performance of Kwik bolts", dated February 3,1%7
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| : 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
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| : 34. Impell Report IM T 0210040238, "Impell/Ebasco Approach Towards Design Verification of Inaccessible Attributes" dated !
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| May 15,1987
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| : 35. Cygna, "Civil / Structured Review Issues List," Revision 0, dated July 21,1987
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| : 36. Communications Report between G. Ashley, et al (Impell); S.
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| Harrison (TU Electric); and W. Horstman et al (Cygna), dated May 14,1987,10:45 a.m.
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| : 37. Impell Calculation M 15, "Base Angle Interaction Diagram i Development," Revision 6 i
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| : 38. Impell Calculation M 25, "Prying Action Factors for Two-bolt Base Plate", Revision 3 l I
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| : 39. Communications Report between G. Ashley (Impell); S. Harrison (TU Electric); and W. Horstman et al (Cygna), dated May 14, 1967, 2:30 p.m.
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| : 40. Communications Report between S. Harrison (TU Electric); S. J.
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| Chen, P. Harrison and F. Hettinger (Ebasco); and W. Horstman, D.
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| Leong, et al (Cygna), dated May 1,1987, 2:30 p.m.
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| TU Electric Comanche Peak Steam Electric Station 6N N k A Independent Asseesment Program - All Phases 111ll11llll1llll1111111ll11111 Job No. 84056 Revision 15 TUE\84056\RIL 1. MAN
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| 07/09/88 Revision 15 Page 14 CABLE TRAY SUPPORTS Review Issues List
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| : 41. Communications Report between S. Harrison (TU Electric); P.
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| Harrison (Ebasco); G. Ashley Impell); and J. Russ et al (Cygna),
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| dated December 1,1987,11:10 (am
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| : 42. Impell Calculations M 95, "Effects of Gap Under Base Angles",
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| Revision 2
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| : 43. Communications Report between S. Harrison et al (TU Electric);
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| P. Harrison et al (Ebasco); R. Kaczkowski et al (Impell); and J.
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| Russ et al (Cygna), dated January 21,1988, 2:30 p.m.
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| : 44. Communications Report between S. Harrison (TU Electric); P.
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| Harrison (Ebasco); R. Kazcowski (Impell); and W. Horstman, (Cygna), dated February 24,1988, 900 a.m.
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| : 45. Communications Report between S. Harrison (TU Electric); P.
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| Harrison, et al (Ebasco); R. Kazcowski (Impell); and J. Russ, et al (Cygna), dated March 7,1988,12:00 p.m.
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| : 46. Communications Report between S. Harrison et al (TU Electric);
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| R. Alexandru et al et al (Cygna), dated March(Ebasco); 17,1988,9d)0G.
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| a.m.Ashley et al (Impell); and J. R
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| : 47. TU Electric Document DBD.CS15,"Qualification of Embedments in Concrete," Revision 2.
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| 4& Communications Report between S. Harrison (TU Electric);
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| P. Harrison (Ebasco); G. Ashley (Impell); and J. Russ et al (Cygna), dated September 15,1987,2:15 pm
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| : 49. Inspell Calculation M 90, "Effect of Sheer on One-Bolt Base Angles," Revision 1.
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| : 50. Impell Calculation M 95, "Effects of Gaps Under Base Angles" Revision 2.
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| =
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| TU Electric Comanche Peak Steam Electric Station A LD L A Independent Assessment Program - All Phases Job No. 84056 Revision 15 1111lll11ll1111111111111111111 'l - - i
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| -, _ _ . _ . - . _ . _ _ _ _ _ _ _ _ _ . - - ._ __ _ . . ~ . . . _ , _ . , _ ,
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| l 07/09/88 Revision 15 Page 15 CABLE TRAY SUPPORTS l Review Issues List Summary: A. Frame Connection Point and Anchor Bolt Pattern Centroid Eccentricity In the design for the anchor bolts, Gibbs & Hill did not properly l account for the eccentricity between the frame connection point ,
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| to the base angle and the anchor bolt pattern centroid. The ;
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| moment due to the eccentricity may cause the base angle to 1 rotate about its longitudinal axis, resulting in: (1) a compressive force along the toe of the angle section and (2) additional l tension in the anchor bolt (s) l l
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| In the design of one-bolt connections, the eccentricity between )
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| the centerline of the anchor bolt and the center of gravity of the attached member was not considered. For the transfer of 1 shear loading from the support frame to the anchorage, this I eccentricity will result in the development of torsion in the support member. j B. Safety Factor on Hilti Expansion Anchors at SSE Levels Gibbs & Hi!rs cable tray support designs employed a safety factor of 4.0 for Hilti expansion anchors for the 1/2 SSE load level. As 1 discussed in Issue No.1, the 1/2 SSE event was assumed to l
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| govern the support desips, without consideration of the reduced j factor of safety on Hilti expansion anchors for the SSE event. l The safety factor for the SSE event will range from 2.5 to 3.0, depending on building and floor elevation.
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| C. Inconsistent Application of ACI 349-76, Appendix B Gibbs & Hill has used the provisions of Reference 12 to qualify several designs. Examples include the qualification of anc wrages and the use of(code provisions as justification for the factors o safety used for Richmor,d Inserts. However, the designs do not comply with other sections of ACI 349-76, Appendix B. For example, Section B.73 statec
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| ! A single expansion anchor used to anchor an attachment i
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| shall be desiped for one-half of the design strength defined herem.
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| l TU Electric Comanche Peak Steam Electric Station 6.8 ( ) 6 A Independent Assessment Program - All Phases
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| 07/09/88 l Revision 15 Page 16 CABLE TRAY SUPPORTS Review Issues List For any of the cable tray support designs em, ploying a single expansion anchor connection, this code provtsion would require a major reduction in the expansion anchor capacity. Cygna beheves that the l>hilosophy of the entire .:xxle appendix should be considered, ratwr than employing selected portions of the code.
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| D. Factor of Safety on Richmond Inserts Gibbs & Hill's cable tray support designs em.)loyed a safety factor of 3.0 for Richmond Inserts for the 1/2 SSE cad level As discussed in Issue 1, the 1/2 SSE event was assumed to govern the support designs, without consideration of the reduced factor of safety on Richmond Inserts for the SSE event. The safety factor for the SSE event will range from 1B to 2.0, depending on the building and elevation. See Item C, above, foi a discussion of ACI 349-76 as it has been applied to Richmond Inserts.
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| E. Richmond Insert Design
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| : 1. Prying action was not considered in the original design of Richmond Insert connec: ions for cable tray supports. To qualify those connections which use Richmond Inserts, Gibbs
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| & Hill performed cakulations which reference the results of the Richmond Insert testing program rerformed 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 l type, but rather that the Hilti expansion anchors were the Itmiting case. Cygna has the following comments regarding these calculations:
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| o The calculations do not account for the instances where the allowable values for 1" diameter Richmond Inserts taken from Gibbs & Hill Specification 2323-SS-30 (Ta =
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| : Va = 11.5 ki;x) may have been used without the prying l factor. This situation could occur whenever a new design was performed after the issue of this specification
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| : or a CMC /DCA allowed a change which affected the Richmond Inserts used in a support installation. Although TU Electric l Comanche Peak Steam Electric Station l AI 6 A Independent Am=rnent Program - All Phases l Job No. 84056 Revision 15 1111111111:1111111111111111111 TUE\84056\RIL-1. MAN l 1
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| 07/09/88 Revision 15 Page 17 CABLE TRAY SUPPORTS Review Issues List Gibbs & Hill has stated that their engineers were instructed to include the prying factor, Cygna could not locate any supporting documentation.
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| o Cygna has concerns on the use of the site testing of Richmond Inserts to justify higher allowable loads than considered in the original design. See Pipe Support Review Issues List, Item 3, for additional detad.
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| : 2. The oript 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 Richmond Inserts in cluster arrangements, Richmond Inserts embedded in the sides of concrete beams, and Richmond Inserts used in spacings less than those originally considered in Gibbs & Hill desips. Since these restrictions were imposed after the origmal design of the Richmond Insert connections was completed, Cygna is concerned that cable tray supports installed using Richmond Insert clusters or Richmond Inserts in the sides of concrete beams may not have been evaluated for the required reduction in allowables.
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| 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 TUGCO ;goup, and a corresponding evaluation of the installation should ave been performed. However, Cygna could not locate any TUGCO Quality Control instructions or procedures regardmg the use of these Richmond Insert clusters (Reference 10),
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| F. Connection Designs
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| : 1. The cable tray supmrt designs use angles or plates at base connections. The cesign drawings and associated design change documents (i.e., CMC /DCAs) specify anchor bolt spacing and member placement tolerances However, these tolerances may be outside the original design limits. Gibbs &
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| 07/09/88 Revision 15 Page 18 CABLE TRAY SUPPORTS _
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| Review Issues List Hill has not fully evaluated the effects of all possible icstallation tolerances on the base member stresses or the anchorages.
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| Cygna's Phase 2 Cheervations CISOO.05 and CIS0007 respectively addrmoed the design of base connections for Detail "E" supports with three directional loadings and Details "A D" base platt, designs (drawing number 2323 E1060101 S).
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| These support connection designs must also be reviewed to assure that the above concerns are addressed. For several additional support types considered in Cygna's Phase 4 review, the installatx>n tolerances allowed by the design drawings were not considered in the design calculations.
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| : 2. For most support t,ypes, the design drawings n'Jow the use of either Hilti expansion anchors or Richmond Inserts for their anchorage to the concrete. For support types A1, A2, A4, D1, D2, Detail "A" (Drawing 2323-E1070001-S and Detail 11 (Drawing 2323-S0905), the design calculations e) valuate the attachments for Hilti expansion anchors, but not for J
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| Rkhmond Inserts.
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| 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. De value of this factor is dependent on the applied load, bolt pattern geometry, and angle thickness. Justification for the une of this factor has not been provided.
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| The installation procedures for cable tray supports allowed the installation of shims between the base angle / base plate and concrete if adequate bearing could not be achieved due to irregularities in the concrete surface, ne use of shims will reduce the contact foot print of the anchorage and may significantly impact the prying effects. De impact of shims was not considered m the base connection designs.
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| 4 TU Electric Comanche Peak Stenn Electric Station
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| l 07/09/88 Revision 15 Page 19 CABLE TRAY SUPPOR'I3 Review Issues List H. Anchor Bolt Substitutions for Detail 1/1H and Details B, C and D For Detail 1H (Gibbs & Hill Drawing 232%S0909), "Hanger Connection Using Hilti Bolts for Regular Cable Tray Supports" a substitution of Richmond Inserts for anchors is allowed by Note 14d (Gibbs & Hill Drawing 232M0901):
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| Detail "1H" with existing (Drawing 1" diameter 232M0909) or 11/2" Richmond Insert Any Hilti exceptmay for be substitute the 11/4" x 131/8" Super Kwik bolt which may be substituted only with 11/2" diameter Richmond Insert.
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| Additional information on the allowable bolt substitutions are provided in DCA 2103, Revision 0:
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| Question: When only one Richmond Insert is available for a twobolt hanger connection, may a combination of one Richmond Insert and one Hilti bolt be used? If so, what is the minimum and maximum distance between the bolts, and what is the allowable tolerance?
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| 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 ;
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| Connection," and the "a" and "b" dimensions shown in '
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| Two Bolt Beam Connection" Tolerances shall be as shown in "Detail 1H," and in 7wo Bolt Beam Connection."
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| The DCA expands the scope of the substitution to include the i Two Bolt Beam Connection" (Details B, C and D on Gibbs &. Hill Drawing 2323-S0903), and does not include the restriction on the i use of a 11/2" diameter Richmond Insert as a substitute for the '
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| 11/4" x 13-1/8" Hilti Super Kwik-bolts.
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| These substitutions are inconsistent with several aspects of the i cable tray su port design calculations. The minimum bolt spacings are 7,15" and 16" for 1" diameter Hilti Kwik bolts, 11/4" diameter Hilti Super Kwik bolts, and 1" diameter Richmond TU Electric Comanche Peak Steam Electric Station I Ai*A Independent Assessment Program - All Phases il11lll;illl11lllll11111111111 Job No. 84056 Revision 15 TUE\S4056\RIL 1. MAN
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| 07/09/88 Revision 15 Page 20 CABLE TRAY SUPPORM Review Issues List l Iraerta, respectively. 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 moment loads on the base connectons, the tensile load in each anchor is calculated by '
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| dividing the a ylied moment by the minimum bolt spacing. The tensile load cistribution due to direct pullout is calculated based on the allowed connection eccentricity. By substituting a Richmond Insert for a Hilti expansion anchor at the spacing and eccentricity, the tensile load in the Richmond Insert may be greater than the previously calculated load. The effect of this substitution on Rxhmond Insert tensile loads has not been considered in the cable tray support designs. In add tion, since DCA 2103 does not limit the size of the Richmond 'nsert to be i substituted for a 11/4" x 13-1/8" Hilti Super Kwik-bo't in the ,
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| beam connection, a 1" Richmond Insert, which has e lower i ca meity than the indicated Kwik bolt, could be uaid as c su stitute.
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| 1 Gibbs & HillfrUGCO was not able to provide the design ;
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| verification documentation for DCA 2103 (Reference 13) l I. Base Angle Boundary Condition Assumptions For trapeze type supports, Gibbs & Hill has assumed that the hanger connections employ,ing two. bolt base angles are free to rotate about the strong axis of the hanger. Since both the welds between the hanger and its base angle and the base angle itself have significant flexural stiffness, this assumption requires timt the connection allow the calculated rotation without base connection failure. Gibbs & Hill has not justified such connection behavior. (See Review Issue 26)
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| Gibbs & Hill assumed that the generic transverse trapeze frames were planar frames. 'Ihe analytical models of the frames, with the exception of the NASTRAN system models, were also modeled as planar frames. By modeling the supports as planar frames, rotations and translations out-ef-plane were prevented.
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| Therefore, at the support reaction points, which were generally base angles, the only reactions that would le recovered were tension and : hear on the base angle and anchor bolt (s) It must TU Electric Comanche Peak Seam Electric Station A NJL A Independent Assessment Program - All Phases
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| 07/09/88 Revision 15 Page 21 ,
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| CABLE TRAY SUPPORTS Review Issues List be noted that the attachment point of the hanger members was eccentric to the anchor bolt centerline, general y on the back of the out**=ading leg of the base angle.
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| When evaluating the base angles, Gibbs & Hill simply applied a tension and shear to the base angle. The distributen in tensile load to the anchor bolts due to the location of the hanger along the length of the anchor bolts was accounted for. However, the shear load was simply divided by the number of bolts. Gibbs &
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| 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.
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| Gibbs & Hill did not properly consider the case of a one-bolt :
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| base angle. These base angles were simply evaluated for the !
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| tensile and shear loads app ied 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 l been noted. Since the connection to the concrete is via a single l bolt, to resist the torsion due to the eccentric application of a l shear reaction, friction between the concrete and the base angle j must be provided. Such considerations were not addressed.
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| J. Installation of Expansion Anchors in Diamond Cored Holes 3
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| Section 3.1.4.23 of Reference 4 discusses the installation of an expansion bolt in an empty but "pre used" hole. Paragraph (a) of that section states:
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| The bolt being replaced has been removed from the I concrete using a clamond core bit of the same nominal outside diameter as the replacement expansion bolt.
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| The replacement bolt shalL be one diameter size larger than the bolt being removed.
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| The Hilti "Architects and Engineers Design Manual" (Reference 5) addresses the bit typ used in drilling holes for Hilti Kwik bolts and Super Kwik bo ts. On page C 4, Note 6a states:
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| i 07/09/88 Revision 15 Page 22 CABLE TRAY SUPPOR'13 Review Issues List All of the technical information pertaining to Kwik-bolts herein (e.g., pullout and shear data) was accomplished using HILTI masonry carbide bits. Before installing the Kwik bolt using another means of drilling (
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| core), contact your local HILTI Field eer forEngm, advice e.g., diamon and proper procedures. l l
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| On page C 1 (Reference 5) a footnote to the installation process description states.
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| To obtain maximum published holding values, use only )
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| HILTI carbide bits. 1 i
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| In discussions with Hilti, Inc., Cygna learned that Hilti expansion anchors installed in diamond core-bored holes will provide ultirnate strengths that are less than those published in the Hilti Design Manual Primarily, the strength reduction is due to the diameter of the core bore bit itself. It has been Hilti's i experience that core bore bits are intentionally supplied at a l larger diameter than the nominal size to account for the !
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| propessive reduction in bit diameter over its life. Thus, at the uuttal bit usage, the bit diameter will be larger than that I required for the bolt hole. It is this hole oversize which causes the reduction in expansion anchor espacity.
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| In order to avoid any such strength reductions, careful control on the bolt hole diameter must be established. Control may be established by measuring the core bit diameter or the ho!c diameter. Cygna has not observed any QC procedures wl.ich l 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. .
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| K. Reduced Allowable I. cads for 1" Diameter Hilti Kwik bolts.
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| Based on expansion anchor capacity tests performed by Hitti, Inc.
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| 4 in 1960, Hilti issued a letter pving reduced ultimate ca scities :
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| for 1" diameter Kwik-bolts. n response to this letter, "UGCO l issued a Significant Deficiency Analysis Report (SDAR) l 4
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| (Reference 6) to evaluate the effect of the reduced anchor bolt j 1 TU Electric ,
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| 07/09/88 Revision 15 Page 23 CABLE TRAY SUPPORTS !
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| Review Issues List j I
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| capacities for support instaliations at CPSES. The resolution of 1 this SDAR was to accept all existing dealgns employing 1" diameter Kwik-bolts by allowing a reduced safety factor of 3.41, and require that all future deaipi efforts use the reduced capacity. 'Ihe USNRC accepteci this resolution (Reference 8)
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| For the review of cable tray supports where the cable tray load with Thermo-lag exceeds the design load, Reference 7, section 3.2.2.1, paragraph (b) stater All hangers shall then be evaluated for actual loads.
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| During this evaluation, all pertinent design changes shall be taken into account. Consideration shall be given to use of actual tolerances, weld undercut undersize,1" diameter Hilti Kwik-bolt revised criteria and actual field 'as-built' configuration.
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| However, Cygna's review of the subject Gibbs & Hill calculttions and a discussion with TUGCO/Gibbs & Hill (Reference 9), veni fied Hilti Kwik bolt allowables had been that used.the original (unrevised)ll TUGCO/Gibbs & Hi felt that the use of the origm' al allowables was warranted, since the calculations reviewed an existing design. This is not consistent with the requirements of .
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| Reference 7.
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| Response: A. Impell and Ebasco have performed studies to determine the magnitude of the effect of the eccentric loading on base plates '
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| and base angles. These studies were performec. using finite element models of typical anchorage configurations and accounted for both the effects of eccentric loading and of plate flexibility t The studies are contained in Reference 16 (ie.
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| and summarized prying action) m Attachments G1 through G6 of Reference 15 and Attachments A and F of Reference 18.
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| i For support anchorage configurations not addressed by the I studies, Impell and Ebasco perform individual analyses using finite element models of the specific anchorage detail Ebasco and Impell have also prepared studies addressing the ,
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| torsion due to eccentric load application on one bolt base angles.
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| 07/09/88 Revision 15 Page 24 CABLE TRAY SUPPORTS l Review Issues List !
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| Ebesco indicated that the eccentricity between the post center of gravity and the anchor bolt centerline was always considered in i RSM ardyses. This was documented in the "Supplemental Directive No. 3(a) for RSM", dated July 25, 1986 which required the use of a rigid link from the member to the bolt location.
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| This directive was issued to amend Ebasco Procedure SAG.CP11, Revision 1.
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| A similar approach was generally used in the ESM models, but was not formally documented. Ebasco has since then revised I sheet 33 of SAG.CP34 to require the modeling of this eccentricity for ESM models. This revised sheet has been issued as an addendum to SAG.CP34. Ebasco will identify all supports which has one bolt base angles and check these to assure that the eccentricities are considered. (Reference 46).
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| Cygna reviewed the Supplemental Directive 3(a) and sheet 33 of SAG.CP34 and accepted the contents.
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| Impell's studies are included in Calculation M-90 (Reference 49)
| |
| This study included an evaluation of a representative sample of 38 one-bolt base angles selected from Impell's scope. The results from finite element models including this eccentricity were compared with those from the production analyses for the same supports. Attributes examined included the support stiffness, support reactions, tray reactions and member stresses. The only significantly impacted attribute was the torsion in the post. The evaluation compar:d the stress interaction ratio for the posts, ,
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| both with and without including the added torsion. In no case !
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| did the consideration of the eccentricity result in a support failure. Based on these results, Impell indicated that it was not necessary to consider this eccentricity in the cable tray support design validation effort.
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| R As discussed under Issue No.1, the cable tray support design I verification evaluates each support for both OBE and SSE loading.
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| In accordance with Section IV.I.f.il of Reference 14, Section 33.6 of Reference 19 and Sections 4.13 and 5.1 of Reference 18, safety factors of 5.0 and 4.0 are used for Hilti expansion anchors i for the OBE and SSE load cases, respectively. !
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| TU Electric Comanche Peak Steam Electric Station d iA Independent Assessment Program - All Phases ll111ll11111111111111ll1111lll Job No. 84056 Revision 15 TUE\84056\RIL-1. MAN 1
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| 07/09/88 Revision 15 Page 25 CABLE TRAY SUPPORTS Review Issues List C. See Reference 35, Civil / Structural Res Issue No. L D. See Reference 35, Civil / Structural Review Issue No. L E. All cable tray support anchorages, including those using Richmond Inserts are individually design verified. As discussed under Issue Na 3.A, Nam and Impell have performed studies to determine the narrect anchor bolt loads, including the effect of prying action.
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| Per Reference 33, Richmond Insert capacities are being verified by SWEC. For a discussion of Richmond Insert allovzables, capacities of Richmond Inserts located in beam sides, capacities of Richmond Insert clusters, etc., see Reference 35, Civil / Structural Review, Issue No. 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 design changes is no longer e concern. See Section III.2 of Reference 14 and Section 4.0 of Reference 18 for the Project requirements. However, as discussed in Reference 29, Ebasco evaluates certsin supports by grouping like supports and analyzing an enveloping support canfig-Han See Issue No. 27 for a discussion of the support grouping techniques. .
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| G. The finite element models used in the base plate and base angle studies discussed in Issue No. 3.A provided justification for the prying factors now used by the Project.
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| A review of the results of the independent studies performed by ImpeJJ and Ebasco showed several differences in the magnitudes of the prying factors developed. Impell stated that there were certain conservatisms inherent in the methods employed by Ebasco. However, for the sake of consistency, Impell elected to ,
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| use Ebasco's more conservative values (Reference 48) l In accordanm with the as-built inspection procedures, the contact area between the anchorage and the concrete is checked. Sh'Jns are also identified on the as-built support drawings. If the gap between the anchorage and the concrete exceeds 1/16", the gap TU Electric Comanche Peak Steam Electric Station dbk A Independent Assessment Program - All Phases 111111111111lll111111ll11lll11 Job No. 84056 Revision 15 TUE\84056\RIL-LMAN l
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| I l
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| 07/09/88 Revision 15 Page 26 CABLE TRAY SUPPORTS Review Issues List is pressure grouted. As a result, only gaps of 1/16" on shimmed anchorages must be evaluated.
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| A joint position was developed by Impell and Ebasco to address the effect of a 1/16" gap on the preducted anchor bolt loads.
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| This position is basec on finite ek; ment analyses of represettative base angle configurations. These at.!yses showed that the gap did not have a significant impact on the anchor bolt interaction ratios when the revised anchor bolt criteria provided in DBDCS-15 (Reference 47) was used. TU Ebetric stated that the DBDCS15 methods would not be used unless a walkdowc was performed to determine if shims existed under the base angle.
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| H. In accordance with Section III.2 of Reference 14 and Section 4.0 1 of Reference 18, the design verification of support anchorage will !
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| be based on the as. built support configurations. For supports which are fully accessible, anchor bolt substitution is no longer a concern. For supports which have inaccessible attributes (e.g.,
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| anchor bolts that are covered with Thermo. lag, inaccessibility due to congestion, etc.) the Project has issued a joint Impell/Ebasco approach towards design verification of inaccessible attributes (Reference 34). This document requires that the worst case anchor bolt substitution be considered for inaccessible bolts.
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| I. Ebasco and Impell have performed finite element studies to ;
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| develop the appropriate boundary conditions for use with the cable tray support modeling.
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| 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 transla'ional displacements and spring constants are developed for the three rotational displacements. The spring constants were ,
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| developed for a large number of standard anchorage l configurations, and Reference 15 requires that spring constants be developed individually for any, support which does not conform to one of the standard configurations.
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| )
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| The Impell study is documented in Reference 31, and summarized in Section 3.2.5 of Reference 19. Impell assumes that the anchorage is rigid for translational displacements and for
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| ~ ~'~
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| TU Electric
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| -= Comanche Peak Steam Electric Station t *!! NJ L Id Independent Assessment Program - All Phases 11111ll111lll11111111111111ll1 Job No. 84056 Revision 15 TUE\84056\RIL-1. MAN
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| l l
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| 1 07/09/88 Revision 15 Page 27 CABLE TRAY SUPPORTS Review Issues List rotations about the two pometric axes of the base angle. Spring constants were developec for rotation about the longitudinal axis ,
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| of the base angle only. The stiffness values are only a function of the number of anchor bolts and thickness of the base angle. i Unlike Ebasco, Impell does provide a large number of stiffness !
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| values and does not require that spring constants be developi '
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| for non-standard anchorage configurations. This is discusseci in Reference 2& See the response to Issue 3A for a discussion of one-bolt base angles. ,
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| J. See Reference 35, CiviUStructural Review Issue No. 7.
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| K. The cable tray support design verifications effert will use the reduced capacities for 1 inch diameter Hilti Kwik bolts. These values are specified in Appendix 2 of Reference 14 and Attachment B of Reference 18. l l
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| Status: A. Closed. l B. Closed.
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| C. Closed for cable trays. For status see Reference 35, I CiviUStructural Review Issue No. L l 1
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| D. Closed for cable trays. For status see Reference 35, !
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| CiviUStructural Issue No. L l E. Closed for cable trays. See Reference 35, CiviUStructural Review Issue No. L for the status of the review of the Richmond Insert allowables.
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| F. Closed. Generic designs are no longer used. However, see Issue No. 27 for the status regarding Ebasco's support grouping method which affects this issue.
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| G. Closed.
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| H. Closed.
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| I. Clo ed. l TU Electric Comanche Peak Steam Electric Station
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| : 6. #n i PJ6 d Independent Assessment Program - All Phases 111ll111!I111111111111111Hl11Job No. 84056 Revision 15 TUE\84056\RIl LMAN
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| 07/09/88 Revision 15 Page 28 CABLE TRAY SUPPORTS Review Issues List J. Closed for cable trays. For status see Reference 35, Civil / Structural Reymw Issue No. 7.
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| K. Closed.
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| 07/09/88 l Revision 15 l Page 29 l CABLE TRAY SUPPORTS Review Issues List
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| : 4. Design of Comoression Members
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| ==References:==
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| : 1. Gibbs & Hill Calculation Binder 232SSCS-101C, Set 1
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| : 2. Gibbs & Hill Calculation Binder 2323 SCS-215C, Sets 2-6
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| : 3. N.H. Williams (Cygna) letter to J.B. George (TUGCO), "Cable Tray Support Review Questions", 84056.022, dated August 17, 1984, Question No. 4
| |
| : 4. Timoshenko and Gere, ' Theory of Elastic Stability",2nd Edition, pages 99 and 100
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| : 5. N.H. Williams (Cygna) letter to J.B. George (TUGCO), "Cable Tray Support Review Questions", 84056.041, dated February 12, 1985
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| : 6. Ebasco Instruction SAG.CP34, "General Instructions for Cable Tray Hanger Analyses for Comanche Peak SES Nos.1 and 2",
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| Revision 11 7 Ebasco Calculation, "Comanche Peak SES Cable Tray Hanger Volume 1", Book 6, "Buckling Study", Revision 1
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| : 8. Impell Report No. 0102101470, "Effective Length Factors or Buckling of Cable Tray Supports", Revision 1
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| : 9. Impell Report No. 0902100018, "Slenderness Ratio Limits for CPSES Cable Tray Supports", Revision 0
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| : 10. Ebasco Procedure SAG.CP.9, "Instructions for Re-Evaluation of Cable Tray Ihngers Affected by the Longitudinal Tie of Transverse Pangers to the Tray for Commanche Peak SES Unit 2", Revision 0 IL Nuclear Construction Issue Group Procedure NCIG-01, "Visual Weld Acceptance Criteria", Revision 2
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| : 12. Ebasco Calculation, "Comanche Peak SES Cable Tray Hanger Volume 1", Book 16, "CTH Dimensional Tolerances", Revision 1 TU Electric Comanche Peak Steam Electric Station ANL A Independent Assessment Program - All Phases l
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| 11:1111111lll111111llltll111ll Job No. 84056 Revision 15 TUE\84056\RIL-1. MAN
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| i 1
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| 07/09/88 Revision 15 Page 30 I
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| I CABLE TRAY SUPPORTS -
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| Review Issues List l
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| : 13. Ebasco Procedures SAG.CP4,"Seismic Design Criteria for Cable Tray Hangers for CPSES Unit 1", Revision 6 and SAG.CP3, "Seismic Design Criteria for Cable Tray Hangers for CPSES Unit 2", Revision 9
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| : 14. Impell Instruction PI-03, "Qualification of cable tray supports",
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| Revision 5
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| : 15. Impell Instruction PI.02, "Dynamic Analysis of Cable Tray Systems", Revision 6
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| : 16. Impell Report 09-0210@l7, "CPSES Cable Tray System Analysisfrest Correlations", Revision 0
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| : 17. Communications Report between S. Harrison, J. Muffett (TU Electric); P. Harrison (Ebasco); R. Wheaton, B.Ramsey (Impell);
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| and N. Williams, S. Tumminelli, D.Leong, J. Russ, W. Horstman (Cygna), dated March 6,1987,11:30 a.rn.
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| : 18. Transcripts of Cable Tray Hanger Design Verifications Meeting between TU Electric, Cygna, Ebasco and Impell held at the CPSES Site, January 26 and 27,1987
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| : 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
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| : 20. Impell Calculation M 56 "Procedure for Refined Effective Length l Factors", Revision 1 l l
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| 2L Communications Report between G. Ashley (Impell) and W.
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| Horstman et al (Cygna) dated May 15,1987,12:30 p.m.
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| : 22. Communications Report between S. Harrison (TU Electric); G. ,
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| Ashley and R. Kaczkowski (Impell); D. Williams (QEST); and J. l Russ (Cygna) dated July 10,1987,10M a.m. j
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| : 23. Communications Report between P. Harrison and F. Hettinger (Ebasco); S. Harrison and J. Nandi (TU Electric); and J. Russ and N. Wilhams (Cygna) dated July 13,1987, 7:00 a.m.
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| TU Electric Comanche Peak Steam Electric Station
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| ,AbpJL A Independent Assessment Program - All Phases 111111111111lll1111111111111ll Job No. 84056 Revision 15 TUE\84056\RIL-1. MAN
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| 07/09/88 Revision 15 Page 31 CABLE TRAY SUPPORTS Review Issues List
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| : 24. Ebasco Response EB.T 3426, "K-factors for Longitudinal Supports", dated August 27, 1967
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| : 25. Communication Report between P. Harrison (Ebasco); S. Harrison et al (TU Electric); G. Ashley (Impell); and J. Russ et al (Cygna),
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| dated September 3,1987,1000 a.m.
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| : 26. Communication Report between H. Schoppmann et al (Ebasco) and W. Horstman (Cygaa), dated September 23,1987,11:50 a.m.
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| : 27. Communication Report between S. Harrison (TU Electric); P.
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| Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated October 12,1987, 9:30 a.m.
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| : 28. Communications Report between S. Harrison (TU Electric); P.
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| Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated November 17,1987, 3:00 p.m.
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| : 29. Impell Calculation B-04, "Effective Length Factors for !
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| Longitudinal Cable Tray Supports" Revision 0
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| : 30. Communications Report between S. Harrison et al (TU Electric);
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| P. Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated February 4,1988,1000 a.m.
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| Summary: A. Compression Members with Slenderness Ratios in 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 A4 and B4, respectively). If the correct unsupported lengths and pinned end conditions are assumed, the slenderness ratio of these members ,
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| for bending about their weak axis will exceed 200. AISC l Specification Section 1.8.4. limits the slenderness ratio for l compression members to 200.
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| 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 TU Electric Comanche Peak Steam Electric Station A WJL i Independent Assessment Program - All Phases Job No. 84056 Revision 15 1111111111lll11111111111111111 TUE\84056\RIL-LMAN
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| 07/09/88 Revision 15 Page 32 CABLE TRAY SUPPORTS Review Issues List 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.
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| 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, Details E, F, G, and H on Drawing 2323-El-060101-S, etc.) Gibbs & Hill used the distance from the face of the concrete to the centerline 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.
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| A value of k = 1.0 was used to calculate the minor axis slenderness ratio, rather than the value of k = 2.0 for cantilevers. A value of k = 1.0 is based on the assumption that the tray will provide lateral bracing at the clamp location.
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| 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.
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| E. Effect of Out of Plumbness on Compression Members The design of compression members assumed that the applied axial load was parallel to the member axis. Gibbs & Hill Installation Specifications 2323-SS.16b 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 for a discussion of this issue.
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| TU Electric Comanche Peak Steam Electric Station A NJL d Independent Assessment Program - All Phases lll11111lll111111ll1ll11111111 Job No. 84056 Revision 15 TUE\84056\RIL-1. MAN
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| 07/09/88 Revision 15 ,
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| Page 33 CABLE TRAY SUPPORTS i Review Issues List 1
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| F. Reduction in Unsupported Length of Compression Members Due to l 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 the L5x5x3/4 base angle is rigid with respect to the 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.
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| G. Consideration of the Allowed Range of Brace Slopes 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 have reduced capacity due to a longer member length.
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| 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). I 1
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| and Impell Studies were (Reference 8) to performed determine theby Ebasco effect appropriate (Reference 7)ive length These k(factors are used in conjunction with the unsupportedfact member lengths to calculate the member slenderness ratios.
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| 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. Impell feels that friction is justified based on the results of the cable tray system testing program (Reference 16). See Issue No.18 for a TU Electric Comanche Peak Steam Electric Station A()L i Independent Assessment Program - All Phases Job No. 84056 Revision 15 111111111111111111111111111111 TUE\84056\RIL-1. MAN
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| 07/09/88 Revision 15 Page 34 CABLE TRAY SUPPORTS Review Issues List discussion of tray clamp behavior In Ebasco's development of k factors, no friction between the tra and clamps is assumed.
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| The calculated k-factors are generall larger than those used by Impell. However, Reference 6 inc two sets of k-factors, those based on Ebasco's studies without friction and those based on Impell's studies with friction.
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| The AISC has provided an interpretation clarifying the definition !
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| of "compression members" and "tension members" as used in Section 13.4 of the AISC Specifications. Members meeting the definition of compression members must satisfy a slenderness ratio limit of 200 and other limits on member compressive stress levels. Tension member slenderness ratios are limited to 300. This is documented in Reference 9.
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| Cygna raised concerns regarding the application of the results of the k factor studies (discussed above) to support configurations i not addressed in the studies. To support their position, Impell and Ebasco performed an additional study (Reference 29) which Cygna has reviewed and accepted.
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| B. The design verification of cable tray supports does 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 minor axis. Since the minor axis slenderness ratio typically governs, there is no need to consider in-plane sidesway.
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| Ebasco, in Reference 6, requires the use of k = 1.0 for in-plane buckling of trapeze type support posts, k = 2.0 for cantilevered supports and k = 2.0 for both components of I< shaped supports.
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| Impell provides similar requirements in Section 413 of Reference 14.
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| Cygna questioned the applicability of the k factors to support posts oriented with the minor axis on the plane of the support, since this configuration was not included in the k factor development studies. In References 21,22 and 23. Impell and Ebasco agreed to provide a study of k factors for in plane N
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| 07/09/88 Revision 15 Page 35 CABLE TRAY SUPPOR'IS Review Issues List sidesway for those supports whose posts are rotated 900 from the orientation considered in the original k factor development. ;
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| Cygna has reviewed the joint response from Impell and Ebasco, l Reference 29, and has found the results acceptable.
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| l C. In accordance with Reference 14, Section 413, Impell uses the distance from the face of the concrete to the 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.
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| Referer.ce 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.
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| The unsupported length is equal to the distance from the face of the concrete to the clamp which will transmit compressive axial load. A value of k = 2.0 is used for buckling about each axis.
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| However, Paragraph 10 of Attachment E allows the consideration of connectivity 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 buckling.
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| D. 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 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 undercut will be repaired. Therefore, there is no need to :onsider weld undercut in the regions of maximum compression. Cygna notes that the USNRC staff has accepted the NCIG VWAC criteria (Reference 11) for use at CPSES.
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| E. Only members that are greater than two degrees out-of plumb are to be individually evaluated. If a member's orientation is within two degrees from plumb, any effects on the member are considered negligible. This conclusion is based on a study periormed by Ebasco (Reference 12) and the results of the cable
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| ~:
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| l l 07/09/88 Revision 15 Page 36 CABLE TRAY SUPPORTS Review Imues List tray system testing (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.
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| Cygna has reviewed the above documents (Reference 12 and 16) anc have accepted the approach. However, see Issue No. 29 for the cumulative effects of this allowance.
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| F. The entire member length, measured from the face of the concrete, will be used by both Ebasco and Impell in calculating the unsupported member length. Ebasco's procedure is contained in Reference 6, Attachment E. Impell's procedure is noted in Reference 15, Section 3.2, Reference 14, Section 4.0 and Reference 8.
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| G. This is no longer an issue. The design verification is based on the as-built configurations of all supports. Therefore, actual brace slopes are used without the need to consider the range of slopes allowed by the original design.
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| Status: A. Closed.
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| B. Closed.
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| C. Closed.
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| D. Closed.
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| E. Closed. The effect of this must be considered in the cumulative effects evaluation. See Issue No. 29.
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| F. Closed.
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| G. Closed.
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| I 1
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| TU Electric Comanche Peak Steam Electric Station 6.8 (p) 6 d Independent Assessment Program - All Phases ,
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| l 07/09/88 l Revision 15 :
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| l CABLE TRAY SUPPORM Review Issues List i
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| : 5. Vertical and Transverse Lnadine on Loneitudinal Tvoe Sunoorts l
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| | |
| ==References:==
| |
| : 1. Gibbs & Hill Calculation Binder 2323-SCS101C, Set 2 l l
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| : 2. N.H. Williams (Cygna) letter to J.B. George (TUGCO),"Cable Tray l Support Review Questions," 84056.025, dated August 21, 1984, questions 3 and 4 1
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| : 3. R.E. Ballard (Gibbs & Hill) letter to N.H. Williams (Cygna),
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| GTN.69437, dated September 10, 1984, with attached calculations l
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| : 4. Gibbs & Hill Calculaton Binder 2323SCS-101C, Set 5 S. Ebasco Instruction SAG.Ct'34, "General Instructions for Cable Tray Hanger Analysis for CPSES Nos. I and 2", Revision 11
| |
| : 6. Ebasco Instruction SAG.CPil,"System Analysis for Cable Tray and Hanger Assembly for CPSES, Units 1 & 2", Revision 4
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| : 7. Impell Instructions PI-02, "Dynamic Analysis of Cable Tray Systems", Revision 6 Summary: Longitudinal trapeze type supports (e.g., L-A1, L-A4, L.C4, etc.) were assumed to act independently of the transverse supports (sec ;
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| Reference 4. Calculations for these longitudinal supports (Reference )
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| : 1) only cons)dered i longitudinal cable tray loads in the design of I frame members and anchor bolts. Since these supports are rigidly 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 the transverse supports (References 2 and 3).
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| Response: The Ebasco and Impell cable tray support evaluations will consider the effects of three dimensional loading on longitudinal trapeze supports.
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| This is implemented in Reference 6 and Attachments B2, Y and Z of Reference 5 for Ebasco's evaluations and Section 33.5 of Reference 2 for Impell's evaluation.
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| Status: Closed.
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| 1 TU Electric Comanche Peak Steam Electric Station dNk A Independent Assessment Program - All Phases !
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| 07/09/88 Revision 15 Page 38 CABLE TRAY SUPPORTS Review Issues List
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| : 6. Sunoort Frame Dead and Inertial Loads
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| ==References:==
| |
| L Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 5,"Cable Tray Supports (Design Criteria and Reference)"
| |
| : 2. Ebasco Instruction SAG.CP34, Tsencral Instructions for Cable Tray Hanger Analysis for CPSES Nos. I and 2", Revision 11
| |
| : 3. Impell Instruction PI.02, "Dynamic Analysis of Cable Tray Systems", Revision 6
| |
| : 4. Impell Report, 09-02104)017, "CPSES Cable Tray System Analysisfrest Correlation", Revision 0
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| : 5. Ebasco Procedure SAGCP11, "System Analysis for Cable Tray and Hanger Assembly for CPSES Units 1 & 2", Revision 4
| |
| : 6. 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
| |
| : 7. Ebasco Respoase EB-T-3029, Attachment 5, "Nodal Point Spacing for Braces", dated 05/15/87
| |
| : 8. Communications Report between P. Harrison et al (Ebasco) and W.
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| Horstman, et al (Cygna), dated June 23,1987,1000 a.m. ;
| |
| : 9. Communications Report between S. Harrison et al (TU Electric);
| |
| P. Harrison (Ebasco); G. Ashley (Impell); and J. Russ et al (Cygna), dated September 3,1987, 2000 a.m.
| |
| : 10. Communications Report between S. Harrison (TU Electric); P.
| |
| Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated October 12,1987, 9.30 a.m.
| |
| : 11. Communications Report between S. Harrison, et al (TU Electric);
| |
| R. Alexandru, et al (Ebasco); G. Ashley, et al (Impell); and J.
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| Russ, et al (Cygna), dated January 18,1988, 9.10 a.m.
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| l TU Electric Comanche Peak Steam Electric Station A NJi l A Independent Assessment Program - All Phases 1111111lllI1111lll11ll11111111 Job No. 84056 Revision 15 TUE\84056\RIL-1. MAN l
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| 07/09/88 Revision 15 Page 39 CABLE TRAY SUPPORTS Review Issues List Summary: 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 deaip of two-way cable tray supports. Such loads should, as a mmimum, be considered m the design of base connections and anchorages.
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| 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 member and anchorage design of longitudinal supports. (See Issue No.18.)
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| 1 B. Support Dead Weight l 1
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| Gibbs & Hill did not consistently consider support dead loads.
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| The support design calculations considered support weight in one of the following ways:
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| (a) The support weight was not considered.
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| (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.
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| (c) The support weight was calculated by considering the actual weight of each of the support's frame members. l (d) A dead load equal to one half the support weight was used .
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| as required by Reference 1, Sheet 3. l Method (b) also led to other problems in the support design.
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| Initially, the tray unit weight was considered 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 psi, or even 35 psi, 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.
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| TU Electric Comanche Peak Steam Electric Station A NJi d Independent Assessment Program - All Phases ll11111111111llll1111lll111lll Job No. 84056 Revision 15 TUE\84056\RIL-LMAN
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| 07/09/88 Revision 15 Page 40 CABLE TRAY SUPPORTS Review Issues List Response: A. The dynamic testing of cable tray system models, as discussed in Reference 4, has demonstrated that friction type clamps will prevent relative displacement between the supports and the cable trays in the tray axial direction. This effect allows the transfer of a portion of the out of plane inertial loads for a transverse support to a longitudinal support elsewhere in the cable tray system (See Issue No.18).
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| 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 the tray and the support for the transfer of out-of-plane loads. This assumption is noted in Attachments B1, Y and Z of Reference 2. Thus, the out-of plane inertial loads are resisted solely by the transverse support. For cases where the support evaluation is performed using the response spectrum method, as discussed in Reference 5, connectivity between the tray and any transverse support is not initially considered. However, in accordance with Attachment Z of Reference 2, all support analyses will be redone assuming connectivity in order to show that the assumption of no connectivity is conservative.
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| 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 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 longitudinal supports elsewhere in the cable tray system.
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| When modeling the cable tray supports, Impell provides nodes at load application points, member connection points, and at intermediate points within an individual member's length in order to represent the distributed member self weight. Ebasco provides nodes only at load application and member connection pomts. In support of such modeling practices, Ebasco provided a study, Reference 7, to quantify the effect of this modeling approach.
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| The study considered the member self weight and mettial effects TU Electric Comanche Peak Steam Electric Station NWJifb A Independent Assessment Program - All Phases 111111lll111111lla111ll111111 Job No. 84056 Revision 15 TUE\84056\RIL-1. MAN
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| i 07/09/88 i Revision 15 '
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| Page 41 ,
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| CABLE TRAY SUPPORTS l Review Issues List l
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| 1 within the member's length 'or a sample of 200 support members. '
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| The sampling was biased to include only highly stressed support members and was intended to envelop all supports within Ebasco's scope. 'Ihe member interaction ratios were compared with those !
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| oripily calculated without considering the distributed self I weight. The study showed that the change in interaction ratio '
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| was not significant. l i
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| B. The support member dead weight is included in the support l models, for both the equivalent static and response spectrum 4 analysis methods. This is specified in Attachments B1, B2, Y and 1 Z of Reference 2 and Reference 5 for Ebasco and in Section 33.2 of Reference 3 for Impelt Status: A. Closed.
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| B. Closed.
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| i l
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| 1 TU Electric Comanche Peak Steam Electric Station L*I ( ) 6 A Independent Assessment Program - All Phases lll1111llll111111111ll1111ll11 Job No. 84056 Revision 15 TUE\84056\RIL-1. MAN
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| 07/09/88 Revision 15 Page 42 CABLE TRAY SUPPOR'IS Review Issues List
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| : 7. Design of Annie Bram Nealectin, Inadine Eccentricity
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| | |
| ==References:==
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| L N.H. Williams (Cygna) letter to J.B. George (TUGCO), "Cable Tray Support Review Questions," 84056.025, dated August 21, 1984, Question Nos. 3 and 4 letter to J.B. George TUGCO), "Cable Tray
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| : 2. N.H. Support WilliamsReview(Cygna)
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| Quest ions" 84056.027, dated (August 27, 1984, Question No. 2
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| : 3. AISC,"Specifications for the Design, Fabrication and Erection of Structural Steel for Buildings",7th Edition, Sections L15.2 and L18.2.4
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| : 4. Gibbs & Hill Calculation, "Cable Tray Support Type SP-7 With Brace. Brace Eccentricity Calculations." Cygna Technical File 84056.11 L223
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| : 5. Gibbs & Hill Calculation Binder 2323-SCS 101C, Set 1, "Verify the Adequacy of Brace L3x3x3/8 of the Governing Support Case C3," Revision 1
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| : 6. Gibbs & Hill Calculation Binder 232MCS101C, Set 2, "Justify the Use of Two L3-1/2 x 3-1/2 x 3/8 Angles to Take the Appropriate 1. cad and Moment Individually in the Longitudinal Tray Supports at the Lower Brace," Revision 6
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| : 7. Ebasco Instruction SAG.CP34, "General Instructions for Cable Tray Hanger Analysis for CPSES Nos.1 and 2", Revision 11
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| : 8. Impell Calculation M.12, "Qualification Procedure for Cable Tray Support Evaluations", Revision 6
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| : 9. Impell Instruction PI.03, "Design Verification of Cable Tray Supports," Revision 5
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| : 10. Impell Instruction PI.02, "Dynamic Analysis of Cable Tray Systems", Revision 6 TU Electric Comanche Peak Steam Electric Station A b Ji i Independent Assessment Program - All Phases 11111ll111lll111111111llll1111 Job No. 84056 Revision 15 TUE\84056\RIL-LMAN
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| 07/09/88 Revision 15 Page 43 CABLE TRAY SUPPORTS Review Issues List
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| : 11. Transcripts of Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna, Ebasco and Impell held at the CPSES Site on January 26 and 27,1987
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| : 12. Communications Report between S. Harrison, J. Muffett (TU Electric); P. Harrison (Ebasco); R. Wheaton, B. Ramsey (Impell); )
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| and N. Williams, S. Tumminelli, D. Leong, J. Russ, W. Horstman 1 (Cygna), dated March 6,1987,11:30 a.m. ;
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| : 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
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| : 14. Impell Report IM P-010,
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| * Criteria for Single Angle Design,"
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| Revision 0, dated May 15, 1987
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| : 15. Impell Calculation M 22, "Compaetness Criteria," Revision 5
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| : 16. Communications Report between G. Ashley (Impell); S. Harrison (TU Electric); and W. Horstman (Cygna), dated, May 14, 1987, 2:30 p.m.
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| : 17. Communications Report between G. Ashley (Impell); S. Harrison (TU Electric); and W. Horstman, et al (Cygna), dated, May 12, 1987, 300 p.m.
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| : 18. Communications Report between G. Ashley (Impell) and W.
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| Horstman (Cygna), dated, May 13,1987,1000 a.m.
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| : 19. J. P. Padalino (Ebasco) letter to O. W. Lowe (TU Electric) !
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| "Design Criten,a for Resolution of (Cygna) Concerns", EB T-3126, dated June 18, 1987
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| : 20. Communications Report between S. Harrison (TU Electric); G.
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| Ashley, R. Kaczkowski (Impell); D. Williams (QEST); and J. Russ (Cygna), dated July 10,1987,10:00 a.m.
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| : 21. Communications Report between S. Harrison, J. Nandi (TU Electric); S. J. Chen, P. Harrison, F. Hettinger (Ebasco); and, J.
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| Russ, N. Williams (Cygna), dated July 13,1987, 7.00 a.m.
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| TU Electric Comanche Peak Steam Electric Station d (p) i A Independent Assessment Program - All Phases 1111111111lll111lllll1111111ll Job No. 84056 Revision 15 TUE\84056\RIL-1. MAN
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| 07/09/88 Revision 15 Page 44 CABLE TRAY SUPPORTS Review Issues List
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| : 22. Communications Report between P. Harrison (Ebasco); G. Ashley (Impell); and M. Engleman, and J. Russ (Cygna), dated September 14,1987, 8:30 a.m.
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| : 23. Ebasco)
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| Communications and J. Russ et al (Cygna), Report datedbetween SeptemberH.24,Schoppmann 1987, 20 et al (0 p.m.
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| : 24. Communications Report between S. Harrison (TU Electric); P.
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| Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated October 12,1987, 930 a.m.
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| : 25. Communication Report between S. Harrison (TU Electric);
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| P. Harrison (Ebasco); R. Kazcowski (Impell); and W. Horstman ,
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| (Cygna), dated February 24,1988, 900 a.m. l
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| : 26. Communications Report between S. Harrison (TU Electric);
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| G. Ashley (Impell); and W. Horstman (Cygna); dated February 9, 1988, LOO p.m.
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| : 27. Impell Instruction PI11, "Cable Tray System Analysis and Qualification Closeout," Revision 3.
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| Summary: A. Double Angle Braces Longitudinal cable tray supports freguently use double angle sections as bracing to resist the longitudinal loads (e.g., L-A4, :
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| L B4, etc), For the member design, loads were assumed to I produce only axial stresses. The induced bending stresses due to I the eccentric end connections were not considered. Neglecting these flexural stresses can result in members which are i under-designed. The design of the double angles assume that j 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.
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| B. Single Angle Braces Transverse and longitudinal cable tray supports typically use angle sections as in. plane braces to resist transverse loads and TU Electric Comanche Peak Steam Electric Station d Ni A Independent Assessment Program - All Phases 111llll1111111ll11111111111111Job No. 84056 Revision 15 TUE\84056\RIL-1. MAN
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| 07/09/88 Revision 15 Page 45 CABLE TRAY SUPPORTS Review Issues List provide bracing points on the vertical members (e.g, A3, A4, B3, 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 axkl stresses. The induced bending stresses Cw to eccentric end conditions were not ccesidered. Thongh it is not explicitly 1 stated in the AISC Specifications, it is standard practice (Reference 3, Sheet 3-59) to consider the bending stresses due to end connection eccentricity and check the interaction ratio considering the principal axes section moduli.
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| C. Twist Buckling Single angle longitudinal braces are typically connected to the support frame by welding along the legs of the angle. 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 twist buckling at load levels below the critical value for Euler buckling. Twist buckling may also be a concern for angles which are supported by evekling on the same leg at each end.
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| Response: A. In Reference 7, Attachment E and Reference 10 Section 3.2.3, it is required that filler plate spacing he checked in accordance with Section 1182.4 of the AISC Specification. If these require-ments are not satisfied, composite action will not be assumed.
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| Further, Cygna's audit indicates that Impell conservatively includes only one of the two angles in the support model when the requirements of Section 1.182.4 are not met for double angles.
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| l See Issue No. 7.B for a discussion of bending of angle sections.
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| 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 multiSied by the connection eccentricity. This is done using hanc calculations performed after the finite element analysis has been completed. The bending moment is resolved TU Electric Comanche Peak Steam Electric Station d i A Independent Assessment Program All Phases 1111111llllll11111111111111111Job No,' 84056 Revision 15 TUE\84056\RIL-1. MAN
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| 07/09/88 Revision 15 Page 46 CABLE TRAY SUPPORTS Review Issues List into two components relative to the angle section's principal axes and bending stresses are calculated in accordance with Reference 3, sheet 3 59.
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| Ebasco calculates axial allowables for single angles using the minor principal axis radius of gyration. The bendin.g stress allowable is 60% of the yield stress for the normal ;oad condition (OBE) allowab le was less than that specified bySince Ebasco.Cygna the AISC had exp Specifications do not provide guidance on allowable bending stresses for angles, it was necessary to review other design codes. Ebasco performed a comparison between the bending allowable specified in the Australian steel specifications and the bending allowable used in the cable tray support evaluations.
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| This comparison showed that the bending allowable was used less than, or equal to, the bending allowables specified in the.
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| Australian code for the range of brace lengths within Ebasco's scope (Reference 19) 1 Impell models brace members using beam elements with full I moment connectivity at the ends for braces welded directly to the support posts and releases one moment when gusset plate
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| )
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| connections are used and ignores the connection eccentricities.
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| Impell performed a study (Reference 8, Appendix B) which showed that neglecting the connectxm eccentricities was more conserva- ;
| |
| tive in the calculation of axial forces in the brace. However, '
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| this study does not address the impact of the end eccentricities !
| |
| on the bending moments in the brace. In addition, the study l concluded that proper end condition assumptions for the brace were important to obtain the proper member response. Impell 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.
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| Impell's conclusion regarding the boundary conditions of brace angle members only addresses the moment connectivity between i the brace and the post, i.e., braces modeled as pin ended 1
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| TU Electric j Comanche Peak Steam Electric Station A bgJL i Independent Assessment Program All Phases 1111llll1lll1lll11111111111111 Job No. 84056 Revision 15 TUE\84056\RIL 1. MAN 1
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| l
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| _ -~ __ - . - - _ - _ _ , . _ . _ , . _ , _ . - . _ - . - - . . _ _ - _ _ . . . _ _ . . . _ . . . . _ . - - - _ ,
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| I l
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| l l
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| 07/09/88 Revision 15 Page 47 l
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| CABLE TRAY SUPPORTS Review Issues List I
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| 1 members will only have axial loads transferred to them from the !
| |
| structure that they are connected to while those members with ,
| |
| rotational connectivity at their ends will transfer moments.
| |
| Given the studies above, Impel has not considered the moments due to eccentricities between the brace angle and post neutral axes. I Impell calculates axial allowables for single angles using the ;
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| minor principal axiu radius cf gyration. Impell Project j Instruction, PI-11 allowed the use of the geometric axis radius of gyration to reduce the slenderness ratio of the brace members if the slenderness ratio exceeds 200. Cygna did not ,
| |
| accept this practice. Impell revised Prop Instruction PI11 to !
| |
| specify only the use of the minor principal axis radius of i gyration (Reference 16) 1 Impell's bending stress allowables are based on equation 6.11 from the Structural Stability Research Council guide on buckling.
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| Cygna questioned Impell's use of these equations for angle sections. (Reference 17) Impell performed a numerical comparison between the allowables specified in the Australian j steel specifications and their bending allowable criteria. This l comparison showed that the allowable bending stress used for the cable tray support evaluations was less than or equal to the l allowable bending stress specified in the Australian code for the i' range of brace lengths within Impell's scope (Reference 14).
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| Cygna understands that Impell's comparison also included a consideration of the compactness criteiia of the angle sections.
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| All but one of the angle sections included in the SUPERPOST member database are compact sections. Impell revised Project Instruction PI-03 to include the compactness criteria.
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| In both the modeling and the bending stress evaluation, Impell uses the brace member's geometric axes section properties.
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| Cygna questioned the use of the geometric axes section properties in the cable tray support models. Impell provided mformation from the LaSalle County Station docket and material based on work at Washington University that states that the use of geometric axes was appropriate when predicting the response of angle sections installed in a manner similar to their application as braces for cable tray supports at CPSES. Cygna TU Electric Comanche Peak Steam Electric Station AN6 A Independent Aenemment Program - All Phases Job No. 84056 Revision 15 1111111111111lll111111111111li TUE\84056\RIL-1. MAN
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| 1 07/09/88 Revision 15 Page 48 CABLE TRAY SUPPOR'I3 Review Issues List 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 agreec that the use of the geometric axes is acceptable in modeling the structures for the prediction of the response of the structure, but does not agree that the use of these properties member strees evaluation is correct. Impell recognized this prior to Cygna comment and increases the flexural stresses in the angle members by a factor of L2.
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| (Reference 8, Appendix F).
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| As a follow up to the above discussion, Cygna reviewed Impell's basis for the L2 factor, usage of a Cm factor of L0 and the relatively small magnitude of the axial loads in single angles.
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| Based on this review Cygna accepted Impell's method.
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| l C. Both Ebasco and Impell have provided evaluations for the twist-buckling of angles. Ebasco's method for evaluation is contained in Attachment V of Reference 7, while Impell's is in Reference 8 and Section 413 of Reference 9. These methods are based on angle sections which are uniformly loaded throughout their cross-section and with an effective length factor of LO.
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| 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 g,overn. Both Ebasco and Impell calculate the length correspondmg to the slenderness ratio where twist bucklieg behavior transitions into Euler buckling.
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| 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 buckling allowable stress. Impell calculated this slenderness ratio by equating the twist-buckling allowable stress to 95% of the Euler buckling allowable stress.
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| By using 95% of the Euler allowable stress, Impell effectively )
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| decreased the maximum length at which twist buckling governs. 1 Therefore, Impell may have checked angles which would be governed by twist buckling with Euler buckling allowables.
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| Cygna noted that the maximum lengths reported by Ebasco and Impell differed for various angle cross-sectxms. Cygna TU Electric Comanche Peak Steam Electric Station AdL 1- Independent Assessment Program - All Phases 111111111111lll111111111111111 Job No. 84056 Revision 15 TUE\84056\RIL LMAN 4
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| , . . . _ _ . . _ . . --c.,.. , . - - - _ . - - - , . , _ ,-
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| _ . _ . _ . _ , , . , _ . - - ,,,.,..,__.,,--,_.,.m -
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| 1 I
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| 07/09/88 l Revision 15 Page 49 l
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| CABLE TRAY SUPPORTS Review Issues List questioned Impell and Ebasco about these inconsistencies. Impell revised their methodology to conform to Ebasco's criteria, as a result of which Impell deleted the use of 95% of the Euler l allowable in determining the critical lengths for twist buckling.
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| Cygna reviewed Impell revised design criteria and noted that !
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| there was little or no difference between lengths reported by l Ebasco and Impell. l Cygna performed a study of the twist-buckling behavior of angle ;
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| sections. As an independent verification of the approach used by ;
| |
| the Project, the purpose of the study was to evaluate the critical '
| |
| buckling stress for two angle sections commonly used at LPSES, L3x3x3/8 and L3-1/2x 31/2x3/8 for three different boundary condition cases:
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| Case L Concentric loading Case 2. Opposite legs loaded at opposite ends Case 3. Same legs loaded at opposite ends.
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| The angle lengths ranged from 18 to 156 inches, which are representative of the lengths found at CPSES.
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| The study for the above cases is an eight part calculation and is discussed in detail in Reference 22. The results of Cygna's study supported the adequacy of the approach used by the Project. ,
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| i Status: A. Closed.
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| B. Closed.
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| C. Closed.
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| i TU Electric Comanche Peak Steam Electric Station N, N)6 N Independent Assessment Program All Phases liktiilllilllllillllllllitill Job No. 84056 Revision 15 TUE\84056\IUL LMAN
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| l 07/09/88 Revision 15 Page 50 CABLE TRAY SUPPORTS Review Imues List l
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| : 8. Dynamic Amolification Factors (DAF1 Tributary Trav Suooort Reuinna and -
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| Missing Mass Effects
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| ==References:==
| |
| : 1. Gibbs & Hill Report, "Justification of the Equivalent Static Imd i Method Using a Factor of 1.0 Times Peak Spectrum Acceleration for the Design of Cable Tray Supports; Comanche Peak Units 1 '
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| and 2"
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| : 2. Communications Report between J. Jan (Gibbs & Hill) and G.
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| Bjorkman (Cygna) dated October 4,1984, 4:00 p.m.
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| : 3. Communications Report between J. Jan, P. Huang, J. Pier (Gibbs I
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| & Hill) and N. Williams, G. Bjorkman (Cygna) 1 September 13,1984, 3:00 p.m. )
| |
| : 4. Communications Report between J. Jan, J. Pier (Gibbs & Hill) and G. Bjorkman (Cygna) dated October 12,1984,101)0 a.m.
| |
| : 5. Communications Report between J. Jan (Gibbs & Hill) and G.
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| Bjorkman (Cygna) dated October 18, 1984
| |
| : 6. Communications Report between J. Jan, et al (Gibbs & Hill); H.
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| Levin (TERA); R. Kissinger, et al (TUGCO); and N. Williams, et al. (Cygna), dated October 31,1984
| |
| : 7. CPSES, FSAR, Section 3.7B3.5
| |
| : 8. Ebasco Procedures SAG.CP4, "Seismic Design Criteria for Cable Tray Hangers for CPSES, Unit 1", Revision 6 and SAG.CP3, "Seismic Design Criteria for Cable Tray Hangers for CPSES, Unit 2", Revision 9
| |
| : 9. Ebasco Instruction SAG.CP34, "General Instructions for Cable Tray Hanger Analysis for CPSES Nos.1 and 2", Revision 11
| |
| : 10. Ebasco Calculation, "CPSES Cable Tray Hanger Volume 1", Books 9 & 10, "Multimode Response Multiplier Studies", Revision 0
| |
| : 11. Ebasco Calculation. "CPSES Cable Tray Hanger Volume 1", Book 15, "Cable Tray Dynamic Load Redistnbution Effects", Revision 1 TU Electric Comanche Peak Steam Electric Station dI i A Independent Assesment Program - All Phases 111lll111ll11111111!!I1111lll1 Job No. 84056 Revision 15 TUE\84056\RIL 1. MAN
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| 07/09/88 Revision 15 Page 51 CABLE TRAY SUPPORTS Review Issues List
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| : 12. Impell Instructions PI02, "Dynamic Analysis of Cable Tray Systems", Revision 6
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| : 13. Transcripts of Cable Tray Har.ger Design Verification Meeting Between TU Electric, Cygna, Ebasco and Impell held at the CPSES Site on January 26 and 27,1987
| |
| : 14. Communications Report between B. Lashkari (JBA); J. Park (Impell); J. Christoudias, D. Fong, P. Harrison, R. Alexandru, SJ.
| |
| Chen, F. Hettinger, J. Swanson (Ebasco); and W. Horstman, D.
| |
| Leong, J. Russ, S. Tumminelli (Cygna), dated February 10, 1987, 8:30 5:00 p.m.
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| : 15. Communications Report between S. Harrison, J. Nandi (TU Electric); G. Ashley, B. Ramsey (Impell); R. Alexandru, P.
| |
| Harrison, SJ. Chen, and F. Hettm, gor (Ebasco); and N. Williams, W. Horstman, D. l.cong, J. Russ, S. Tumminelli (Cygna), dated February 12,1987,1000 a.m.
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| 1
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| : 16. Communications Report between S. Harrison (TU Electric); R.
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| Alexandru, S. J. Chen, P. Harrison, F. Hettinger (Ebasco); B. ,
| |
| Atalay, D. Leong, J. Russ and S. Tumminelli (Cygna), dated July :
| |
| 23,1987,1:45 p.rn. j
| |
| : 17. Communications Report between S. Harrison (TU Electric); SJ.
| |
| Chen et al (Ebasco); and B. Atalay et al (Cygna), dated August 13,1987, 9:45 a.m.
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| l
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| : 18. Communications Report between S. Harrison (TU Electric); R.
| |
| Alexandru et al (Ebasco); and B. A'alay et al (Cygna), dated August 13,1987, 4:15 p.m.
| |
| : 19. Communications Report between SJ. Chen et al (Ebasco) and W.
| |
| Horstman et rl (Cygna), dated September 25,1987,11:30 a.m.
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| l TU Electnc Comanche Peak Steam Electric Station l
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| '. N N J k d Independent Assessment Program - All Phases Job No. 84056 Revision 15 11111lll11111111ll111111111111 TUE\84056\RIL-LMAN l
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| . - . .q. _ , . _ . - . . , . - _ . - - _m.. - g - re-- - - .-.--
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| 07/09/88 Revision 15 Page $2 CABLE TRAY SUPPORTS Review Issues List Sumraary: A. Equivalent Static Analyses Gibbs & Hill performed cable tray support designs using an "equivalent static analysis" to account for seismic loads. The tray dead load on a support was calculated by the tributary span method. The tray seismic ked was the product of the tray dead load and the peak spect:al acceleration for the jven building elevation. A dynamic amplification factor (DA3 was not included as required by Reference 7 (see also Issue No. 25.A)
| |
| An additional factor tc be considered is the ratio of the static reaction for a continuous beam to the reaction calculated by the tributary 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 performed several generic studies for cable tray support qualification using cable
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| < tray system models and the response spectrum analyses method.
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| In general, Gibbs & Hill did not check the analysis results for sufficient mass participation in the response spectrum analyses.
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| Response: A. Impell performs all cable tray support qualifications using cable tray system models and the response spectrum method. System models will accurately capture the support reactions for the continuously supported tray. A dpamic amplification factor is not required when performing respcase spectrum analyses.
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| Impell's approach is discussed in Reference 12.
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| Ebasco performs support qualifications usir/ static, equivalent static, and response spectrum methods. Se system models analyzed using the response spectrum analysis method are similar to those used by Impell and do not need to consider this issue as indicated above. When performig support qualification by the sts'ic or equivalent statx: methods, Ebasco uses a multimode respor.se multiplier (MRM) of 1.25. E he MRM accounts for both the dynamic amplification and the support reactions for the l
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| TU Electric Comanche Peak Steam Electrw Station
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| continuously supported tray. The development of this factor is l documented in References 10 and 11.
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| Cygna had numerous concerns regarding trending of results and applicability of the MRM factors to all systems at CPSES. These concerns are discussed in Reference E Ebasco provided a response to Cygna's concern in Reference 17. Cygna reviewed this response and had several additional quest %s which were clarified by Ebasco as a final submittal of their MRM position paper (Reference 18). After reviewing Reference 18, Cygna had several additional follow up questions which Ebasco verbally responded to in Reference 19. On the basis of Ebasco's calculations and verbal responses, Cygna accepted the MRM study.
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| B. For all response spectrum analyses performed for cable tray support qualification, a missing mass correction will be incorporated. Ebasco uses the missing mass option of P-Delta '
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| STRUDL and Impell uses the missing mass correction in SUPERPIPE. See References 13 and 14.
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| Status: A. Closed R Closed.
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| : 9. Reduction in Channel Section Procerties Due to Clamn Bolt Holes
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| ==References:==
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| L N.H. Williams (Cygna) letter to J.B. Geor e GCO), "Cable Tray l and Conduit Support Review Questions," 015, dated August ;
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| 6,1984, Attachment B, Question No. 2 !
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| : 2. Gibbs & Hill Calculation 2323.SCS111C, Set 8, Sheets 34-39, ;
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| included in letter GTN 69371, dated August 23, 1984 ;
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| : 3. AISC "Specification for the Design, Fabrication and Erection of Structural Steel for Buildings",7th Edition
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| : 4. Ebasco Instruction SAG.CP34, "General Instructions for Cable Tray Hanger Analysis of CPSES Nos.1 and 2", Revision 11
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| : 5. Impell Instruction PI 11, "Cable Tray System Analysis and Qualification Closcout", Revision 3, with addendum dated January :
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| 19, 1987 I
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| : 6. Impell Instructions PI 02, "Dynamic Analysis of Cable Tray Systems", Revision 6
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| : 7. Transcripts of Cable Tray Hanger Design Verification Meeting betvicen TU Electric, Cygna, Ebasco and Impell held at the l CPSES Site, January 26 and 27,1987
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| . Transcripts of Cable Tray Hanger Design Verification Meeting l between TU Electric, Cygna, Ebasco, Impell, and SWEC held at the CPSES Site, on April 21,1987
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| : 9. Ebasco Calculation, "CPSES Cable Tray Hanger Volume 1" Book 25, "Reduction in Section Properties due to Bolt Holes,"
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| Revision 0
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| : 10. Impell Calculation M 65, "Reduction in Section Properties Due to Bolt Holes" Revision 3 1L Communications Report between P. Harrison et al (Ebasco) and W.
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| Horstman et al (Cygna) dated June 23,1987,1000 a.m.
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| i TU Electric Comanche Peak Steam Electric Station !
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| : 12. Communication Report, between P. Harrisou, et al (Ebasco); S.
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| Harrison (TU Electric); and W. Horstman et al (Cygna), dated April 29,1987,10.15 a.m. and 2:00 pm
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| : 13. Communications Report between S. Harrison (TU Electric);
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| P. Harrison et al (Ebasco); G. Ashley et al (Imp:ll); and J. Russ et al (Cygna), dated November 19,1987,9.20 am Summary: The AISC Specification (Reference 3), Section 1.10.1 states:
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| Riveted and welded plate girders, cover plated beams and rolled or welded beams shall in general be proportioned by the moment of inertia of the gross section. No deduction shall be made for shop or field livet 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 1.143, exceeds 15 percent of the gross flange area, the excess shall be deducted.
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| Cygna found instances where the areas of bolt holes, used for the cable tray clamp bolts, exceeded 15 percent of the gross flange area, and the required reduction in moment of inertia had not been considered m the design calculations.
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| An evaluation of this issue should consider the following items:
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| o Cable trays may be placed anywhere in the beam span (for example, see CMC 2646) o The case for cantilevered supports where one tray is close to the wall and other trays are located further out from the wall.
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| o The effect of DCA 17838, which provides bolt hole gage tolerances, and allows the use of 3/4" diameter holes for 5/8" diameter bolts.
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| o All unused flange holes are not required to be plug welded and may be present in high moment regions. See Note 15 on Gibbs & Hill Drawing 2323 S-0901, Revision 4.
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| Response: The reduction in channel section properties due to bolt holes will be considered la the design vuification of ceble tray supports.
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| 07/09/88 Revision 15 Page 56
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| - CABLE TRAY SUPPORTS Review Issues List As a basis for the bolt hole size considered, Ebasco, in Reference 7, indicated that a sample of over 200 used bolt hoks 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 ciameter.
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| Irr.pell considers the effect of a 3/4 inch diameter bolt hole located at the tip of the channel flange or at the actual hole location, if available, per Section 23.2 of Reference 5. Used bolt holes will oc identified on the as-built support drawings. Unused bolt holes are assumed to occur at any location in the support. The unused bolt hole must be assumed to occur in the area where its presence will cause maximum stress. The effect of the section reduction will only be considered if th2 interaction values exceed specified levels.
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| Ebasco follows a similar procedure to consider the effect of bolt holes, as required by Attachment E, Item 11, of Reference 4.
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| Ebasco and Impell both derive the ratios of net to gross section properties p., area, section modulus and moment of inertia:
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| (A) net /(A) gross, (Sxx) net /(Sxx)groes and (Syy) net /(Syy)groes), Cygna noted several differences in the section property values reported by Impell and Ebasco.
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| To resolve these differences Cy reviewed Impell's calculations (References 9 and 10) and not that in calculatmg reduced section properties with the bolt holes, Impell did not consider the neutral axis shift while Ebasco did. Impell contended that such a shift was not necea,ary and provided references to several steel design text books (Gaylord and Gaylord, Salmon and Johnson) to support their position. Impell also noted that the shift in neutral axis would not ,
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| l occur for a member with bolt holes at one cross section. The stress distributien would only be distorted in the vicinity of the hole, where the local stress and the strain distribution would vary. This behavior
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| ! would be true for both major and minor axes behavior. i l
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| Cygna agreed with Impell's explanation and noted that Ebasco had l used a more conservative approach in the calculation of section properties by including the neutral axis shift.
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| 07/09/88 Revision 15 Page 57 CABLE TRAY SUPPORTS Review lesues List Status: Closed i
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| : 10. System Concent .
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| )
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| ==References:==
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| L N.H. Williams (Cygna) letter to J.B. George (TUGCO), "Cable Tray l Support Review Questions," 84056.031, dated August 31, 1984, Attachment A, Question No. 2 l
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| : 2. L.M. Popplewell (TUGCO) letter to N.H. Williams (Cygna), dated September 28, 1084 with attached cakulations )
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| : 3. Ebasco Instruction SAG.CP34, "General Instructions for Cable Tray Hanger Analysis for CPSES No.1 and 2", Revision 11 l i
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| : 4. Ebasco Procedure SAG.CP11, "System Analysis for Cable Tray and Hanger Assembly for CPSES Units 1 & 2", Revision 4 l
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| S. Ebasco Calculation, "Comanche Peak SES Cable Tray Hanger )
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| Volume 1", Book 2; "Computer Related Information", Revision 3 '
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| : 6. Ebasco Calculation, "Comanche Peak SES Cable Tray Hanger Volume 1", Book 7:"Cable Tray Hanger Load Application Location Studies", Revision 1
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| : 7. Ebasco Procedures SAG.CP4, "Seismic Design Criteria for Cable I Tray Hangers for CPSES Unit 1", Revision 6 and SAG.CP3, ;
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| "Seismic Design Criteria for Cable Tray Hangers for CPSES, Unit !
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| 2", Revision 9 l l
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| : 8. Impell Instruction PI-02, "Dynamic Analysis of Cable Tray Systems", Revision 6
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| : 9. Impell Calculation M 12, "Qualification Procedure for Cable Tray Support Evaluations", Revision 6
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| : 10. Impell Report 0102101470, "Effective-length Factors for Buckling of Cable Tray Supports", Revision 1
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| : 11. Impell Instruction PI 07, "Design Verification of Base-Plates, Base Angles, and Embedded Plates", Revision 4 j
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| 07/09/88 Revision 15 Page 59 CABLE TRAY SUPPORTS Review Isues List
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| : 12. Communications Report between S. Harrison (TU Electric);
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| P. Harrison (Ebasco); G. Ashley (Impell); and W. Horstman et al (Cygna), dated September 15,1987, 2:15 p.m.
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| : 13. Communications Report Between S. Harrison (TU Electric);
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| P. Harrison (Ebasco); R. Kazcowski (Impell); and W. Horstman (Cygna), dated February 24,1988, 9:00 a.m.
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| Summary: In order to justify certain design asumptions questioned by Cygna (Reference 1), documentation was provided indicating that Gibbs & Hill had assumed that the cable tray and suprts act as a system.
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| (Reference 2.) As part of this "systems approach, the following behavior was assumed:
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| 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 cou>les between adjacent supports. More specifically, for longitudina' supports (e.g, SP-7 with brace, Detail 8, drawing 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.
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| 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.
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| Such moment transfers as described above are only possible if full rotational and trar.Nional compatibility exists between the cable tray and suppo'.t beate The relative stiffness between the trays and their supprts can mA sffect the percentage of the moment to be balanced by the load couples between supports.
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| Gibbs & Hill asumes that the compatibility is provided by the heavy duty and friction types of tray clamps. See Review Issue TU Electric Comanche Peak Steam Electric Station A di A Independent Assessment Program - All Phases Job No. 84056 Revision 15 1111111111ll11111111111111llll TUE\84056\RIL-1. MAN
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| 1 07/09/88 j Revision 15 Page 60 CABLE TRAY SUPPORTS I 1
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| Review Issues List 18 for a discussion of Cygna's concerns regarding the clamp behavior.
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| B. Bracing for Compression 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.)
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| C. Independence of Transverse and Longitudinal Supports For trapeze ty x supports, the longitudinal and transverse support systems act incependently. Therefore, the longitudinal supports are designed for longitudinal loads only, i.e., no transverse or vertical load contribution is considered. (See Issue No. S.)
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| D. Base Angle Rotation Additional tensile forces introduced by rotation of the base angles about the bolt pattern control is minimized by to the tray.
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| (See Issue No. 3A.)
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| E. Out of Plane Inertial Loads 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 Issue No.
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| 6, these inertial loads have not been considered in Gibbs & Hill's design of longitudinal supports.
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| F. Member Connection Eccentricities The cable tray supprts use channel sections for the beam and ;
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| hanger members. The typical connection between the beam and I hanger is a lap joint, with the channels attached back-to-back. l This type of connection will introduce bending moments and J torsxm in the mere Jue to the eccentricity between the section neutral axe eference 1, Question No. 2.2.)
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| Review Imues List Gibbs & Hill addressed this issue in Reference 2, indicating that a portion of the effect is resisted as additional loads in the cable tray, and the net effection the stress level in the support is an increase of less than three percent.
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| Response: A. The design verification of cable tray hangers will 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.
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| B. See Issue No. 4.A for a discussion pertaining to the bracing for compression members.
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| C. See Issue No. 5 for a discussion pertaining to the treatment of longitudinal and transverse supports.
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| D. See Issue No. 3.A for a discussion pertaining to the treatment of base angle rotation.
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| E. See Issue No. 6.A regarding the treatment of out-of plane inertial loads.
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| F. The effects of the eccentricities between members are considered in the design verification of the cable tray supports.
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| 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.
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| Impell, in Reference 8, Section 3.2.3 and Reference 9, specifies how the eccentricities will be considered. The method used by ;
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| Impell in modeling lapped joints is consistent with Ebasco's ;
| |
| approach. However, for other connection geometries, Impell's approach differs from Ebasco's. Cygna has reviewed these ,
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| differences and found the impact not to be significant.
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| i Status: A. For status, see Issue Nos.18, 24.A, 24.B, 24.C, and 24.D.
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| 07/09/88 Revision 15 Page 62 CABLE TRAY SUPPORTS Review Imues List B. For status, see Imue No. 4.A and 18.
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| C. For status, see Imue No. 5.
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| D. For status, see Issue No. 3.A.
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| E. For status, see Issue No. 6.A.
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| F. Closed.
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| ==References:==
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| L Gibbs & Hill Calculation Binder 2323-SCS 215C, Sets 2-6
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| : 2. Gibbs & Hill Calculation Binder 2323-SCS101C, Set 3, Sheets ,
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| 234-243, Revision 9
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| : 3. Gibbs & Hill Calculation Binder 2323-DMI13C, Set 1 j
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| : 4. Gibbs & Hill Report, "Justification of the Equivalent Static Load Method Using a Factor of L0 Times Peak Spectrum Acceleration for the Design of Cable Tray Supports; Comanche Peak Units 1 and 2" i 1
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| : 5. Ebasco Procedures SAG.CP4, "Seismic Design Criteria for Cable l Tray Hangers for CPSES, Unit 1", Revision 6 and SAG.CP3, "Seismic Design Criteria for Cable Tray Hangers for CPSES, Unit 2", Revision 9
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| : 6. Impell Instructions PI-02, "Dynamic Analysis of Cable Tray Systems", Revision 6 ;
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| 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 support type D1 (References 2 (
| |
| and 3) and the Dynamic Amplification Factor Study (Reference 4).
| |
| The analysis models consist of identical supports, separated by equal spans. This modeling will influence the system frequencies and seismic response and may not be representative of an actual installation, where a mixture of support types, non-uniform spans and tees or elbows in the trays are used.
| |
| Response: The design verification for cable tray supports is based on the as-built support configurations and cable tray routing. This is specified in Reference 5, Section HL2 for Ebasco and Reference 6, Section 3.2.1 for Impell The results of the Gibbs & Hill NASTRAN models will not be used.
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| The dynamic amplification factor used by Ebasco is based on a study performed using a ser es of uniform supports at various spacings. This TU Electric Comanche Peak Steam Electric Station Ad A- Independent Assessment Program - All Phases 11111llll11llll111111111llllll Job No. 84056 Revision 15 TUE\84056\RIIA. MAN
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| Review Issues List I i
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| study is similar to the evaluation performed by Gibbs & Hill See Issue No. 8 for a discussion of this study.
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| Status: Closed for the original Gibbs & Hill NASTRAN models. See Issue No.
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| 8 for the status of the dynamic amplification factor study performed j by Ebanco. ;
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| : 12. Working Point Deviation Study
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| ==References:==
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| : 1. Gibbs & Hill Calculation Binder 2323-SCS-215C, Sets 2 6
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| : 2. Gibbs & Hill Calculation Binder 2323-SCS-216C, Sets 1-5
| |
| : 3. AISC, "Specification for the Design, Fabrication and erection of I Structural Steel for Buildings",7th edition l
| |
| : 4. Gibbs & Hill Report, "Cable Tra Raceway System Dynamic Analysis Program," March 19,198 l S. Communications Report between M. Warner (B&R/TUGCO QC) and i W. Horstman, J. Russ (Cygna) dated November 16, 1985 1
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| : 6. Gibbs & Hill Drawing 2323-S0903
| |
| : 7. Communications Report between B.K. Bhujang et al (Gibbs & Hill); ;
| |
| R.M. Kissinger (TUGCO); and W. Horstman et al (Cygna) dated ,
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| September 14, 1984 l
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| : 8. TU Electric, CPSES, "Generic Issues Report - Evaluation and Resolution of Generic Technical Issues for Cable Tray Hangers",
| |
| Revision 1
| |
| : 9. Ebasco Instruction SAG.CP34, "General Instructions for Cable Tray Hanger Analyses for CPSES Nos.1 and 2", Revision 11
| |
| : 10. Transcripts of the Cable Tray Hanger Design Verification and Meeting between TU Electric, Cygna, Ebasco, and Impell held a i the CPSES Site, January 26 and 27,1967 l
| |
| : 11. Communications Report between S. Harrison (TU Electric);
| |
| P. Harrison et al (Ebasco); G. Ashley et al (Impell); and J. Russ l et al (Cygna), dated November 19,1987, 920 a.m. I
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| : 12. Communications Report between S. Harrison et al (TU Electric); l G. Ashley (Impell); J. Russ et al (Cygna), dated December 8,1987, i 11:30 a.m.
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| l l
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| 07/09/88 Revision 15 Page 66 CABLE TRAY SUPPORTS Review Issues List
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| : 13. Communications Report between S. Harrison et al (TU Electric);
| |
| P. Harrison (Ebasco); G. Ashley et al Impell); and J. Russ et al (Cygna), dated December 9,1987,1:30 (p.m.
| |
| : 14. Communications Report between R. Kaczkowski et al (Impell) and J. Russ (Cygna), dated January 12,1968,12:40 p.m.
| |
| : 15. Impell Calculation M 92, "Effect of Working Point Deviations of In Plane Braces on Trapeze Supports" Revision 1
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| : 16. Communications Report between S. Harrison et al (TU Electric);
| |
| R. Alexandru et al (Ebasco); G. Ashley et al (Impell) and J. Russ et al (Cygna), dated January 18,1988, 9*.10 a.m.
| |
| : 17. Communications Report between S. Harrison et al (TU Electric),
| |
| P. Harrison et al (Ebasco), R. Kaczkowski et al (Impell); and J.
| |
| Russ et al (Cygna), dated January 21,1988, 2:30 p.m.
| |
| Summary: 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 of all members at a connection intersected at a common point, thus no connection eccentricities were considered.
| |
| The connection details shown on the design drawings (e.g., Details 4 and 5 on Reference 6) piovided a brace working pomt location which was not consistent with the design assumptions.
| |
| Based on a discussion with TUGCO 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. The following are comments on the analyses performed as a part of this study.
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| A. Consideration of Design Change Documentations I 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 Issue No.
| |
| 2LA.)
| |
| l 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.
| |
| B. Vertical and Transverse Loads on Longitudinal Supports The effects of vertical and transverse loads on longitudinal support frames were not considered in the Working Point Deviation Study. (See Issue Nos. 5 and 10.)
| |
| C. Assumptions Regarding Governing Components The portion of the study that evaluated longitudinal trapeze supports only checked member stress interaction as spfied in Section ild of Reference 3. No evaluation was mace to ensure ;
| |
| that the connections, base angles and anchor bolts are also l adequate. l D. Modeling Assumptions L Instead of modeling a longitudinal support in the tray run, one end of the tray was assumed to be fixed. The effect of '
| |
| this tray boundary condition on the system response was not justified. Based upon the review of the NASTRAN models used in the Dynamic Analysis Program (Reference 4), Cygna i TU Electric Comanche Peak Steam Electric Station A ("J a A Independent Auemment Program - All Phases Job No. 84056 Revision 15 11111111111111111ll1111111ll11 TUE\84056\RIL LMAN
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| 07/09/88 i Revision 15 Page 68 CABLE TRAY SUPPORTS Review Issues List learned that Gibbs & Hill's modeling of these fixed ends did l not account for the response spectrum input at those points, I but instead fixed them to an absolute rigid ground. If the l same modeling technique was applied in the Working Point Deviation Study, the results of those response spectrum analyses may be incorrect.
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| : 2. The analysis assumed a single 24-inch tray per supx>rt level and did not assess the impact of more realistic mu tiple tray loadings or other tray widths.
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| : 3. Eccentricities were not properly modeled (See Issue No.10)
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| : 4. The cable trays were modeled as translationally and rotationally fixed to the support beams. This assumption of tray attachment fixity was not justified (See Issue No.18)
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| : 5. The run configurations selected may not be representative of actual installations. Parameters include systems of identical supports, uniform 8'.6" support spacing, and the assumed worst case frame dimensions (See Issue Nos.11 and 28)
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| : 6. The base angle modeling assumed 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)
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| : 7. Excitation in the longitudinal tray direction was not considered.
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| : 8. The out.of-plane translational degrees of freedom were restrained on trapeze type supports, resulting in an unrealistically restrained system.
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| E. Controlling Element of Supports Gibbs & Hill did not check all support components when I determining the controlling support element. For example, support l type E4 was assumed to be limited by the load capacity of the i Hilti expansion anchors. Cygna's review indicated that the actual J
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| TU Electric Comanche Peak Steam Electric Station Ad6 d Independent Assessment Program - All Phases ll!!1!!!I11111111lll1111111111 Job No. 84056 Revision 15 TUE\84056\RII 1. MAN
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| -_-__.__D
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| 1 1
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| 07/09/88 ,
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| Revision 15 ;
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| Page 69 CABLE TRAY SUPPORTS Review Issues List governinj; com:x>nent was the Richmond Inserts which were not checked )y Gi>bs & Hill l 1
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| F. Working Point Location for Two. Bolt Brace Connections on Longitudinal Supports.
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| The workinj; point location shown on the design drawing does not i l
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| coincide witi the actual line of action of the brace load for two bolt brace connections, e.g., Details "F" and "G" on Gibbs & l Hill Drawing 2323-S-0903, and the brace concrete attachments for ;
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| support types L Al through L-A4, L-B1, L B2, L-B4, L C1, L-C2 l and L.C4 on Gibbs & Hii Drawing 2323-S0902. 'Ihese offsets I
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| may induce larger tensile loads in the anchorages than originally considered in the designs. These connections were not evaluated !
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| as part of the Working Point Deviation Study. l l
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| G. Arbitrary Allowed Working Point Deviations l
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| Several support types within Cygna's review scope have specified allowable working point deviations without any supporting calculations. ,
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| : 1. Detail N (Gibbs & Hill Drawing 2323 E1060101-S)
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| Gibbs & Hill Cakulation Binder 2323-SCS 216C, Set 3, Sheet 5 indicates an allowable deviation of 9" 13" for brace connection to beam. Cakulations are not included.
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| : 2. Detail V (Gibbs & Hill Drawing 2323 El.0601-01-S)
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| Gibbs & Hill Cakulation Binder 2323-SCS 216C, Set 3, Sheet 5 states "Low Stress, Brace Working Point Deviation of 6" is acceptable." Cakulations to support this statement are not included.
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| i H. Working Point Deviations by Similarity l
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| Several support types within Cygna's review scope have specified l allowable working point deviations based on similarity to standard support types.
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| i l
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| l TU Electric Comanche Peak Steam Electric Station 6.i [J6 A Independent Assessment Program - All Phases lll1111lll11ll111111ll11111111 Job No. 84056 Revision 15 TUE\84056\RIL-LMAN !
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| CABLE TRAY SUPPORTS Review Issues List ;
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| L Detail J (Gibbs & Hill Drawing 2323-E10601013) is qualified 1 by similarity to Case B3.
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| : 2. Detail 11 (Gibbs & Hill Drawing 2323.S.0905) is qualified by i similarity to Detail 8 (Gibbs & Hill Drawing 2323-S0903).
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| 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 deviatxm. Case-by. case evaluations of Case B3 and Detail 8 supports were performed to determine if all as-designed supports were acceptable. The support types which had been qualified by sunilarity were not included in these case-by-case reviews; hence, there is no assurance that they are not overstressed also.
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| I. Use of Enveloping Cases The Working Point Deviation Study evaluates several support j types by grouping them with an enveloping support of similar configuration. Reference 1, Set 2 evaluates two groups. Group 1 l includes support types A3, B3, and C3, considering type C3 to l envelope the other two. Group 2 includes support types A4, B4, i and C4, considering type C4 to envelope the others. For each l analysis, the enveloping type is found to be overstressed, and a l case by. case asdesigned review of supports of that type is i conducted. The enveloped types are not all included in the case-by. case reviews, and a separate evaluation is not performed 1 to show design adequacy of the other support types on a generic basis.
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| J. Compressive 1. cad Capacity of Members i
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| Gibbs & Hill considered the effect of multiple, discrete axial loads on the buckling capacity of the hangers. Gibbs & Hill did not properly apply the effect, since the factor is a function of 1 the applied loading, and Gibbs & Hill did not calculate it for each load case. (Reference 7.)
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| Response: In accordance with Reference 8, Appendix A12, the cable tray support !
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| design validation effort will not rely upon the results of Gibbs & Hill's i Working Point Deviation Study. Cable tray supports will be evaluated i
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| TU Electric Comanche Peak Steam Electric Station
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| : 6. N I J k A Independent Assessment Program - All Phases l Job No. 84056 Revision 15 1111111llll1111111111111111111 TUE\84056\RIL 1. MAN
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| 07/09/88 Revision 15 Page 71 CABLE TRAY SUPPORTS Review Issues List on an individual basis using as-built support configurations.
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| Reference 9, Attachment I provides details for the consideration of the brace working point deviation in the support finite element models.
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| Both Ebasco and Impell use these guidelnes. For braces attached directly to the back of a vertical channel a set of conditions are provided such that if these conditions are satisfied, the working point deviation need not have to be modeled. During a discussion between Cygna and Ebasco (Reference 10), Ebasco indicated that the specified conditions are based on the requirement that if the brace neutral axis passes through the panel zone (defined by the intersection of the post and tier), the brace working point location will have no effect on the behavior of the support. This is specified in Attachment I of Reference 9.
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| Cygna asked for the justification for the criteria used. Ebasco indicated that the criteria provided was based on engineering judgment, not an analysis. After a careful review of the enteria, Ebasco determined that the limitations on working point deviation provided in the criteria were not sufficiently stringent. As a result of this, the criteria was revised. This revised criteria required the reevaluation of all cable tray supports which employed the earlier cn'ena.
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| Impell reviewed the supports within their scope and stated that the modeling technique, as specified in Attachment I of Reference 9, was only used for design venfication of 16 cable tray su.> ports (Reference 12), and agreed to revise their design procedure to celete the tolerances allowed in Attachment I of SAG.CP34. Impell provided a calculation evaluating the 16 supports considering the revised criteria (Reference concerns regard15) ing the qualification of several individual supports.Cy These concerns were subsequently resolved.
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| Ebasco has revised their procedure for working point and reanalyzed all supports that did not conform the revised criteria (Reference 13)
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| Cygna has reviewed Ebasco's and Impell's revised procedures and found
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| , them to be acceptable.
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| Status: Closed.
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| TU Electric Comanche Peak Steam Electric Station
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| : ALJt A Independent Assessment Program - All Phases Job No. 84056 Revision 15 1111111ll11111111111111ll11111 TUE\84056\RIL 1. MAN
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| ._,____m
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| 07/09/88 Revision 15 Page 72 CABLE TRAY SUPPOR'IS Review Issues List
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| : 13. Reduced Socctral Accelerations
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| ==References:==
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| L Gibbs & Hill Calculations, "Analysis of Alternate Detail 1"
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| : 2. Gibbs & Hill Calculation Binder 2323-SCS 101C, Set 3, Sheet 247, Revision 9
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| : 3. Gibbs & Hill Calculation Binder 2323-SCS-215C, Set 4
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| : 4. Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 2, Sheets 131 ;
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| & 132, Revision 5 I
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| : 5. Ebasco Procedures SAG.CP4, "Seismic Design Criteria for Cable l Tray Hangers for CPSES Unit 1", Revision 6 and SAG.CP3, i "Seismic Design Criteria for Cable Tray Hangers for CPSES Unit 1 2", Revisioa 9 j
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| : 6. Ebasco Instruction SAG.CP34, "General Instruction for Cable Tray Hanger Analysis for CPSES, Nos. I and 2", Revision 11 i
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| : 7. Impell Instruction PI.02, "Dynamic Analysis of Cable Tray l Systems", Revision 6 j
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| : 8. Communications Report between P. Harrison, et al (Ebasco); and W. Horstman, et al (Cygna); dated, June 23,1987,1000 a.m.
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| : 9. Communications Report between S. Harrison et al (TU Electric); 1 P. Harrison (Ebasco); G. Ashley (Impell); and J. Russ et al l (Cygna), dated, September 9,1987,10:00 a.m. l
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| : 10. Coramunications Report between P. Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated December 10, 1 1987, LOO p.m. I 1L Communications Report between S. Harrison et al (TU Electric);
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| P. Harrison et al (Ebasco); R. Kaczkowski et al (Impell); and J.
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| Russ et al (Cygna), dated January 21,1988, 2:30 p.m.
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| Summary: For the qualification of the aupports discussed below, Gibbs & Hill used reduced spectral acceleratons based on a calculated support tray system frequency. '1hese analyses assumed that all supports on a tray TU Electric Comancbe Peak Steam Electric Station
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| '$M6* A Independent Awamment Program - All Phases (l!!!111111111111111111111!I11Job No. 84056 Revision 15 TUE\84056\RII-LMAN
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| 07/09/88 Revision 15 Page 73 CABLE TRAY SUPPORTS Review Issues List run are of the same type and have equal spacings (See Issue No.11.).
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| These studies are not representative of the cable tray installations at CPSES.
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| A. Transverse Supports A reduced acceleration was used for the analysis of transverse supports, such as type A4, which was used in analysis of Alternate Detail 1 (Reference 1). This acceleration corresponds to a calculated frequency which is higher than that corresponding to the spectral peak. This frequency was calculated using a system model of identical supports equally spaced at 8'6" and a tray weight of 35 psf. De results of this study may not be valid for all installations, as discussed in Issue No.11.
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| B. Longitudinal Supports For longitudinal supports (e.g., type SP-7 with brace (Reference 3), L-Al (Reference 2, etc.), the frequency calculations did not include the effect of the axial frequency of the tray and the eccentricities between the tray and support.
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| C. Effects of Base Angle Flexibility The flexural flexibility of the base angle supporting the brace of the longitudinal supports was not considered m frequency calculation (References 3,4) Flexural deformation of the base angle can result in significant reduction in support frequency.
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| Response: The current cable tray support design verification effort does not rely on the results of the Gibbs & Hill analyses discussed in this issue.
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| Cable tray supports are design verified based on the as-built tray and support configurations.
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| A. In accordance with Reference 5, Sections III.1, III.2 and IV.2.c, Ebasco calculates cable tray system frequencies based on the as-built support configurations and tray spans. De seismic input accelerations are based on these frequencies. In accordance with Reference 7, Impell analyzes the cable tray supports using response spectrum analyses of system models based on as-built TU Electric Comanche Peak Steam Electric Station ALJ6 A Independent Assessment Program - All Phases 11111111lll111ll11111111111111Job No. 84056 Revision 15 TUE\84056\RIL-1. MAN
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| 07/09/88 Revision 15 Page 74 CABLE TRAY SUPPORTS Review Issues List geometry. The techniques used by Gibbs & H.ill are not employed.
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| B. For equivalent static stress analyses of longitudinal supports.
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| Ebasco considers the axial stiffness of the tray Reference 5, Section IV.2.c) and the effect of the eccentriciti(es b support and the tray. In the calculation of the support frec uency in the longitudinal tray direction for equuvalent static ana yses, Ebasco lumps the tray mass at the tier centerline neglecting the vertical eccentricity to the tray center of gravity.
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| This will overpredict the support-tray frequency. Ebasco stated that inclusion of the eccentricity would result in an unrealistically low frequency since the tray provides rotational stiffness (Reference 8)
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| Subsequent to the above discussion Ebaxo provided a response to Refererce 9) which pertained to the vertical Cygnas location ofconcern lumpe (d masses in longitudinal supports used in frequency calculations. Ebasco's response contained an analysis of a multilevel tray system on cantilever type supports. A comparison was made between the frequencies as calculated by ESM and RSM techniques. For one tray level, the ESM overpredicted the frequency; however, when combined with an MRM of L25 for the longitudinal direction, the response of the system was conservatively over predicted. This overprediction was based on the conservative value of the MRM for longitudinal excitation (Reference 10)
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| For Ebasco's and Impeil's response spectrum systems analyses, tray stiffness and support eccentricities are considered.
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| C. Ebasco and Impell have performed studies to determine the ap3ropriate stiffness for base angle connections. These stiffness va ues are included in Ebasco's support models (Reference 6, Attachment G9) and Impell's system models (Reference 7, Sections 3.2.5) See Issue No. 3J for a discussion of the base angle stiffness studies.
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| Status: A. Closed.
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| f
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| 'I'U Electric Comanche Peak Steam Electric Station d()6 A Independent Amaraunent Program - All Phases 11111111111ll111ll111111111111 Job No. 84056 Revision 15 TUE\84056\RIL-1. MAN
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| - _ , , . . . - - , - ~,__~ .,_._.,,-.,. _- ,__._e- ..~_,-c-._,, . . . - . . - . , . _ , , . . . , . _ , ,
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| 07/09/88 Revision 15 Page 75 CABLE TRAY SUPPORTS Review Issues List B. Closed See Issue No. 24 for concerns regarding the modeling of the eccentricities between the tray and the support and Issue No.
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| 29 for the cumulative effect of this issue.
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| C. Closed l
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| l TU Electric Comanche Pea ca Electric Station 9 m at Program . All Phases iMstAi !"! K 8*56 x " "'" 5 TUEs84056\RIL-1 MAN
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| 1 07/09/88 l Revision 15 Page 76 CABLE TRAY SUPPORTS l Review Issues List
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| : 14. Non.Conformance with AISC Soecifications
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| ==References:==
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| L AISC, "Specifications for the Design, Fabrication and Erection of Structural Steel for Bulklings",7th edition
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| : 2. CPSES, FSAR, Sections 3A32 and 3a42
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| : 3. Ebasco Procedures SAG.CP4, "Seismic Design Criteria for Cable 1 Tray Hangers for CPSES, Unit 1", Revision 6 and SAG.CP3, !
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| "Seismic Design Criteria for Cable Tray Hangers for CPSES, l Unit 2", Revision 9 l
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| : 4. Transcripts of the Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna, Ebasco and Impell held at the !
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| CPSES Site on January 26 and 27,1987 j
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| : 5. Impell Instruction PI.03, "Design Verification of Cable Tray Supports", Revision 5
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| : 6. Communications Report between S. Harrison, J. Muffett (TU ;
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| Electric); P. Harrison (Ebasco); R. Wheaton, B. Ramsey (Impell);
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| and N. Williams, S. Tumminelli, D. Leong, J. Russ, W. Horstman (Cygna), dated March 6,1987,11:30 a.m.
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| 1
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| : 7. Ebasco Instruction SAG.CP24, "General Instructions for Cable !
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| Tray Hanger Analysis for CPSES Nos. I and 2", Revision 4 i
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| : 8. Impell Report No. 09021N)017, "CPSES Cable Tray System Analysisfrest Correlations", Revision 0
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| : 9. ANCO Testing laboratories, Document No. A.000150, "rest Plan - -
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| Dynamic Testing of Typicel Cable Tray Support Configurations," l Revision 1 l
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| : 10. Impell Special Study No. 5.9, "Oversize Bolt Holes", Preliminary Issue IL Transcripts o' the Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna, Ebasco, Impell, JBA and SWEC held at the CPSES Site, May 19, 1987 TU Electric Comanche Peak Steam Electric Station A NJi A Independent Assessment Program - All Phases l111111lll11111111111llll11111 Job No. 84056 Revision 15 TUEs84056\RIL-LMAN
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| l 07/09/88 l
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| Revision 15 Page 77 j CABLE TRAY SUPPORTS Review Issues List i i
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| : 12. Ebasco Response, EB T 3029, Attachment 7, "Bolt Hole Oversize j Statistical Study," dated May 15, 1987 j
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| : 13. Ebasco Position Paper, "Effects of Bolt Hole Oversize in CrH j System Adequacy," Revision 2, June 19,1987 l
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| : 14. Ebasco Calculation, "Comanche Peak SCS Cable-Tray Hanger, l Volume 1," Book 22, "Statistical Analysis of Bolt Holes /Edg.,
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| Distances," Revision 1 i
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| : 15. Communications Report between P. Harrison (Ebssco) and B. l
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| , Atalay, W. Horstman (Cygna), dated June 25,1987, 3:00 p.m.
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| : 16. Communications Report between G. Ashley (Impell); and S.
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| Tumminelli, W. Horstman (Cygna), dated May 13,1987, 5:30 p.m. ,
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| l
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| : 17. Communications Report between G. Ashley (Impell); S. Harrison (TU Electsic); and W. Horstman et al (Cygna), dated May 14, 1987,2:30 pm .
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| l
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| : 18. Impell Instruction PI11, "Cable Tray System Analysis and Qualification Closcout," Revision 3 j
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| : 19. Communications Report between P. Harrison, et al (Ebasco); and, W. Horstman, B. Shakibnia (Cygna), dated June 23, 1987, 1000 a.m.
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| I
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| : 20. Ebasco Letter EB T-3422, "Ebasco's Responses to Cygna's Questions on Calculation Volume 1, Book 22 and the Oversize ,
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| Bolt Hole Position Paper," dated August 27, 1987 j
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| : 21. Ebasco Response EB T-3426, "Unsupported Lengtli for Lateral .
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| Torsional Buckling" dated August 27, 1987 l
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| : 22. Communications Report between J. Christoudous et cl (Ebasco);
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| and J. Russ et al (Cygna), dated September 24,1987, 2:00 p.m.
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| : 23. Communications Report between S. Harrison (TU Electric); P.
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| Harrison (Ebasco) G. Ashley et al (Impell); and J. Russ et al (Cygna), dated November 17,1987, 3:00 p.m.
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| TU Electric Comanche Peak Steam Electric Station ALJL A Independent Awument Program - All Phases illilitilllilillil!Illlililiti Job No 84056 Revision 15 TUE\84056\RIlel. MAN
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| I 07/09/88 Revision 15 Page 78 CABLE TRAY SUPPORTS Review Issues List )
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| l
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| : 24. Communications Report between S. Harrison, et al (TU Electric), l P. Harrison et al (Ebasco), G. Ashley et al (Impell); and J. Russ et al (Cygno), dated December 10,1987, 9.20 a.m.
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| 25.
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| Communications Harrison Ebasco); andReport J. Russ between et al (CygnaG. Ashley),et dated Decemberal10, (Impell); P.
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| 1987,1.00 (p.m.
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| 26.
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| Communications Report between S. Harrison (d J. Russ et alTU Electri (Cygna), dated )MarchAshley 7,1988,12.00 p.m.(Impell ; P. Harrison et al (Ebas
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| : 27. Impell Analysis No. 0210041, ' Torsional Restraint Relative Tier Stiffness," dated December 17, 1987 Summary: The CPSES FSAR, Section 33, Reference 2, commits to designing the cable tray supports in accordance with the AISC Specifications, Reference L Gibbs & Hill has not properly considered the requirements of Reference 1, as discussed below.
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| A. Unbraced Length for Axial Buckling Section 1A4 (Reference 1) requires that the slenderness ratio, kl/r, be less than 200 for compression members. Depending on the approach selected 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 ;
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| direction, the L value should be taken as 2.0 for trapeze type 1 and cantilever type supports. Consequently, kl/r = 257 for a 5' 9" C6x8.2 hanger or beam. ,
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| B. Unbraced Length for Lateral Torsional Buckling l Section L5.L4.6a (Reference 1) requires that Equation L5-7 be used to cakulate the allowable bending stress for channels. In the denominate'r, T is the unbraced length of the compression flange. Cygna found the following iw=== where the AISC Specifications were not considered or were improperly applied:
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| L Gibbs & Hill's Working Point Deviation Study (Issue No.12) uses 22 kai for the allowable flexural stress without checking TU Electric '
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| Comanche Peak Steam Electric Station 6.8 I. ; 6 A Inde ndent Amnesament Program - All Phases lllll11ll111111111111111111111 Job o. 84056 Revision 15 TUE\84056\RIL LMAN
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| i I
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| 07/09/83 Revision 15 Page 79 CABLE TRAY SUPPORTS .
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| Review Issues List Equation 1.57. Since the frame heights are on the order of i 144", an allowable flexural stress of :.5 ksi is calculated by .
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| Equation 1.5-7. l
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| : 2. Detail SP-7 and similar supports consider T to be the l distance from the base attachment to the tray centerline and not to the outside tray rail where the load is applied. Use of the larger distance will result in lower allowable bending stresses. ;
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| C. Bolt Holes in Member Flanges r
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| Reductions in the section properties of beams due to bolt holes in their flanges yr Section 1.10.1 (Reference 1), were not considered (See lssue No. 9).
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| D. Iacing of Double Angles i Double angle braces are daigned as composite members, withou providing lacing per Section 1.18.2.4 (Reference 1) (See Issue No. l D i E. Eccentric Connections Section 1.152 (Reference 1) discusses eccentric connections. Thts j section requires that any axial members not meeting at a single i working point be designed for the eccentricities. For example, ;
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| this section of the specification applies to supports with single angle braces (SP 7 with brace, lea 1, etc)L The gusset plates connected to ti.ese braces must also be designed for the eccentricities.
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| F. Oversize Bolt Holes Section 1.23.4 (Reference 1) specifies bolt holes to be 1/16" larger than the nominal bolt diameter. 'Ihe 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 norr.inal bolt diameter.
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| Therefore, the bolt holes in Gibbs & Hill's designs should be TU Electric i
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| l 07/09/88 Revision 15 Page 80 CABLE TRAY SUPPOR'IE Review Issues List 1
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| considered oversized and should be treated as such in bearing )
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| connection calculations.
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| O. Use of the Allowable Compressive Stress For Secondary Members )
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| l For the design of the longitudinal brace for support type SP-7 with brace, the brace was assumed to be a secondary member, and allowable compressive stresses were calculated per section 1.5133 (Reference 1). Since this is the sole member providing longitudinal load carrying capability, it should be considered a primary member, and sections 1.5.13.1 and 1.5.13.2 are applicable.
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| H. Member Length for Use in AISC Equatior.1.6-la. l See the discussion for Item H in the Response section below. !
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| 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 Equation L5-7 or the calculation of the uasupported length. In Reference 4, Ebewo indicated that the total length of the tier members (horizontal channels) and the length of the post (vertical channeia) between tiers is to be used as the unsupported length.
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| Impell, Reference J, Section 4.1.4, specifies that the full length of the tier member shall be used as the unsupported length and that 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 channels. In Reference 18, Impell allows a reduction in the unsupported length for posts in order to reduce the number of failures for posts with high bending stresses and long unsuported lengths. By doing so, Impell has assumed that the tiers will provide bracmg to the posts to inhibit lateral torsional buckling, thus allowing the use of the distance between tiers i .t the unbraced length. Cygna, per Reference 15, was unable to locate any documentation to support this asumption and believes that the tiers may not be capable of providing bracing to the compression flanges of the posts.
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| TU Electric Comanche Peak Steam Electric Station A 5i A Independent Assessment Program - All Phases lll11llllll11111ll111111111!!1 Job No. 84056 Revision 15 TUE\84056\RIL-1. MAN
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| 1 CABLE TRAY SUPPORTS i Review Issues List '
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| l Subsequent to the above discussion _it was agreed upon that the validity of the effective torsional bracing point for the post i provided by a t!er could be evaluated through a finite element 1 analysis. Impell performed an analysis for tie support )
| |
| configuration shown in Figure 1 of Reference 25. Loading in this configuration induced torsion in post and minor axis bending in tier. Since the ratio of bending moment in the tier and the torsional moment in the post member are representative of relative stiffness of two members, it was suggested (Reference
| |
| : 24) that if this ratio exceeded 3 then the tier could be considered as a point of lateral torsional bracing for use in AISC Equation 1.5-7.
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| The results of the above analysis, Reference 27, support Impell's and Ebasco's design procedure which considered the tier to act as a lateral torsional bracing point for the post.
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| C. See Issue No. 9.
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| D. See Issue No. 7.A.
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| E. See Issue Nos. 7.A and 7.B for a discussion of the eccentricities )
| |
| associated with single and double angle braces. The effect of l eccentric loading on the gusset plates used at the ends of angle braces is also considered.
| |
| Ebasco evaluates the gusset plates for combined effects of axial load and bending by considering eccentric loading. Since the STRUDL output only provides the u.ial load, the bending moment on the gusset plate is based on the eccentricity between the gusset plate centerline and the center of one leg of the brace (Reference 7) The gusset plate is analyzed as a beam, with the cross sectional area and the section modulus calculated, based on the full width of the plate. For braces which are skewed relative to the plate, the applied loads are transformed into the geometric axes of the gusset plate. The weld between the gusset plate and the supporting member is also checked for the axial load and the bending moment (Reference 22)
| |
| TU Electric Comanche Peak Steam Electric Station dIdi i Independent Assessment Program - All Phases 1111111ll11lllll111111llllll11 Job No. 84056 Revision 15 TUE\84056\RIL-1. MAN
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| 07/09/88 Revision 15 Page 82 CABLE TRAY SUPPORTS Review Issues List A similar approach is followed by Impell, Reference 5, i Attachment 7. However, since Impell models the braces as fixed l ended members, applied moments are developed in the finite i element models.
| |
| F. In Reference 10, Impell addresses the oversized bolt holes used for the anchor bolts and the tray clamps. 'Ihis report indicates j that the use of 1/8" oversized holes is standard practice for ;
| |
| anchor bolts and, therefore, their vae is not an issue. For the clamp bolts, it is indicated that the additional relative i displacement of the tray and support is not significant. In fact, j 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 supports used in the ANCO dynamic testing !
| |
| program (Reference 9) include installations with oversized bolt j holes. T: t impact of the oversized heles is investigated in the ;
| |
| correlations of the tes', results to those for finite element I models (References 8 and 14). Cygna's review of the ANCO test l plan indicates that 1/S" overstzed bolt holes are used in two test i configurations. j Ebasco has prepared a calculation involving a statistical analysis ;
| |
| of a sample of bolt hole sizes and edge distances. The ,
| |
| calculation was to determine the maximum bolt hole size present :
| |
| in the cable tray support components (Reference 14). Ebasco has i also prepared a position paper, "Effect of Bolt Hole Oversize on CTH Adequacy" (Reference 13), which summarizes the results of ,
| |
| the statistical analysis end offers quantitative justification for !
| |
| the adequacy of support iristallation with oversize bolt holes. J Cyysa provided Ebasco with a list of questbns on the validity of the conclusions of the various studies. Subsequent to the !
| |
| above discussion Ebasco provided responses to Cygna's questions !
| |
| regarding the bolt hole study. Cygna has reviewed and accepted j Ebasco's responses.
| |
| G. For the cable tray support design validation effort, all members, !
| |
| including bracing members will be evaluated using the allowable l TU Electric i Comanche Peak Steam Electric Station t ANL A Independent Assessment Program - All Phases i ll1lll111ll1111111111111111111bb No. 84056 Revision 15 TUE\84056\RIL-1. MAN l i
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| _ _ . _ _ , _ . . _ . . . _ . . . ~ . , _ , _ . - , _ , , . . - _ _ _ , _ . . _ _ , , _ . . _ , _ . .
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| t 1 ;
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| 07/09/88 Revision 15 ;
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| Page 83 ;
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| I CABLE TRAY SUPPORTS i
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| Review Imues List i
| |
| compresnon stremes for primary members. This is required in !
| |
| Reference 7, Attachment E for Ebesco and Reference 5, Section 4.L3 and Attachments 4 & 5 for Impell.
| |
| H. Members behaving as beam columns, i.e., those subjected to l combined axial and flexural loads, are to be evaluated per the ;
| |
| requirements of Sections 141 and 1A2 of Keference L Cn page !
| |
| 5132 of the Commentary to Reference 1, it states: 'The l maximum bending moment between points of support, however, is i used to compute the bending stress for use in Formula (L6 la)."
| |
| Formula 14.la is applicable to those members which are ,
| |
| experiencing compressive axial stresses as well as flexural l stresses, j Impell and Ebasco use the code checking capabilities of their finite element analysis programs (SUPERPOST for Impell and :
| |
| STRUDL for Ebasco) to qualify the various members which j comprise a cable tray support. In performing the code check for ;
| |
| Formula L6.la, both of tbese programs scan an individual element's stresses and moments, select the highest values for the :
| |
| quantity and then use these quantities in the formula. However, !
| |
| each individual element may only be a portion of an actual ;
| |
| member. For example,if the member in question is a post fmm ;
| |
| a tmpeze support with two tiers, the programs would look at two indnadual post segments: Between the uppermost tier and the ;
| |
| ceiling anchorage and bctween the two tiers. However, Cygna '
| |
| amerted that the entire member length, front the a..-horage to the elevation of the lower most tier is the correct lergth to scan over for 11, maximum moments *o be used in Formula L6-la.
| |
| Impell stated the use of a Cm value of LO would i ecw.t for not scanning over the member length. (Reference 161 Eoasco stated that they believe that the STRUDL code check module is correct in its interpretation (Reference 19). Subsequent to the above discussiors with both consultants, Cygna agreed that the approach used was conservative.
| |
| Status: A. See Issue No. 4.A.
| |
| l B. Closed.
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| TU Electric Comanche Peak Steam Electric Station
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| : 6. 8 N J i a Independent Assessment Program - All Phases 1111111lllll11!!!Il111;,111111 Job I'o. 84056 Revision 15 TUE\84056\RIL-LMAN i
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| a-,4 , --m -
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| 4 i
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| L lillllllllllllllllllllllllllIl
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| - - ,-. - -... .. _ _ _ .. , . . -....,,.. --. .._ . , . ~-..
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| l 07/00/88 Revision 15 Page 84 CABLE TRAY SUPPORTS Review Issues List 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 i angle braces. The issue pertaining to the evaluation method for gusset plates is closed l F. Closed 1
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| G. Closed I
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| l H. Closed l
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| i 1
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| l l
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| l TU Electric Comanche Peak Steam Electric Station rd i l i d Independent Assessment Program - All Phases 11111111ll1lllll1111111111ll11 Job No. 84056 Revision 15 TUE\84056\RIL-LMAN
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| I l
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| 1 07/09/88 Revision 15 Page 85 ,
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| CABLE TRAY SUPPORE Review Issues List
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| : 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 345 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 6 and SAG.CP3, '
| |
| "Seismic Design Criteria for Cable Tray Hangers for CPSES, Unit 2", Revision 9
| |
| : 5. Ebasco Instruction SAG.CP34, "General Instructions for Cable Tray Har.ger Analysis for CPSES Nos. I and 2", Revision 11
| |
| : 6. Impell Instruction PI.02, "Dynamic Analysis of Cable Tray Systems", Revision 6
| |
| : 7. 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 1
| |
| : 8. Impell Instructions PI11, "Cable Tray System Analysis and Qualification Closecut", Revision 3
| |
| : 9. Transcripts of the Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna, Ebasco, Impell, JBA and SWEC held at the CPSES Site, May 19, 1987
| |
| : 10. Impell Report IM-T 0210440 238, "Joint Impell/Ebasco Approach Toward Design Verification of Inaccessible Attributes," dated May 15, 1987.
| |
| IL Communication Report between S. Harrison (TU Electric); I P. Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al .
| |
| (Cygna), dated October 12,1987, 9.30 a.m.
| |
| TU Electric Comanche Peak Steam Glectric Station A L A Independent Assessmcat Program - All Phases lililllilllilllllinlilllillli Job No. 84056 Revision 15 TUE\84056\RIl 1. MAN
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| l 1
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| l l
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| 07/09/88 Revision 15 Page 86 CABLE TRAY SUPPORTS Review Issues List l
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| l Summary: Note 9 on Gibbs & Hill Drawing 2323 4 0901, Revision 4, states: )
| |
| Structural members shown on drawing numbers 232:LS-900 serics may be substituted by one step heavier shape of the same size.
| |
| l This note can be interpreted to allow the craft to substitute a j member from one series with a member from another series, e.g., an ,
| |
| American Standard Channel (C) for a Miscellaneous Channel (MC) or l vice versa, as long as the substituted shape is heavier than, but of the '
| |
| same depth as the original memb::r. Cygna is concerned that this note !
| |
| allows the use of substitute s:ctions which are heavier, but have lower l section moduli.
| |
| At a later date, Reference 2 was issued, providing the following I clarification:
| |
| Structural members shown on drawing numbers 2323-S-900 series may be substituted by a member of the same size and next heavier shape determined by the material on site. The next step heavier l shape will be governed by sections as shown in AISC Manual of Steel Construction. Examples are shown on sheet 2 of 2. l The examples shown on sect 2 of Reference 2 include the substitution of a C4x7.2' er a C4x5.4, a C6x10.5 for a C6x8.2, etc.
| |
| This clearly indicates that de substitution should be of the same series as the specified member.
| |
| Cygna's concern is what types of substitutions were perfermed by the craft and accepted by the QC !nspectors during the time between the issuance of Reference 3 and Reference 2. C)gna was unable to locate any requirements for documenting membei substitutions.
| |
| Within Cygna's walkdown scope, such a substitution was identified i for support numbu 6654 (See Issue No. 20). The design required an MC6x12, and the krtalled member was a C6x13, which has a smaller section modulus (Sx = 5.80 in3 for a C6x13 compared to Sx = 6.24 in3 for an MC6x12)L For the other supports listed in TU Electric Comanche Peak Steam Electric Station L*h @ji i. Independent Assessment Program - All Phases 111111lllll1I111ll1111ll111111 Job No. 84056 Revision 15 TUE\84056\RIL-1. MAN !
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| l
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| 07/09/88 Revision 15 Page 87 CABLE TRAY SUPPORTS Review Issues List Issue No. 20, the required MC6x12's were substituted with C6x82's, a substitution not permitted by Reference 2.
| |
| Response: The design verifications for cable tray supports will use the as. built support drawings. The analyses and stress evaluations will be based on the installed member sizes. 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 determined (inaccessible attributes) the as-designed member size will be used, considering the potential substitution of an American Standard channel
| |
| ("C") of one step heavier for a miscellaneous channel ("MC") if the substitution will result 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 for the Impell/Ebasco unified approach for inaccessible attributes.
| |
| l Status: Closed.
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| TU Electric Comanche Peak Steam Electric Station s.N (d 6 d Independent Assessment Program - All Phases ll11lll11111111111111111111111Job No. 84056 Revision 15 TUE\84056\RIL 1. MAN
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| 07/09/88 Revision 15 Page 88 CABLE TRAY SUPPORTS Review Issues List
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| : 16. Weld Design and Soccifications
| |
| | |
| ==References:==
| |
| L 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 & 2 Mill) and W. Horstman, J. Russ, N. Williams (Cygna) dated October i 27, 1984 i
| |
| : 3. Communications R.y>rt between S. Chang, P. Huang (Gibbs & :
| |
| Hill) and W. Horstman, J. Russ, N. Williams (Cygna) dated l November 13, 1984
| |
| : 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 Review Questions," 84056.041, dated February 12, 1985
| |
| : 7. Ebasco Procedures SAG.CP4, "Seismic Design Criteria for Cable Tray Hangers for CPSES, Unit 1", Revision 6, and SAG.CP3, "Seismic Design Criteria for Cable Tray Hangers for CPSES, Unit
| |
| - 2", Revision 9
| |
| : 8. Ebasco Instruction SAG.CP34, "General Instruction for Cable Tray Hanger Analysis for CPSES Nos.1 and 2", Revision 11
| |
| : 9. Impell Instruction PI.03, "Design Verification of Cable Tray Supports", Revision 5
| |
| : 10. 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 TU Electric Comancte Peak Steam Electric Station
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| -[JL A Independent Amessment Program - All Phases llllll111111111111ll1111111111 Job No. *G56 Revision 15 TUE\84056\RIL-2. MAN wew
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| 1 l 07/09/88 I Revision 15 Page 89 CABLE TRAY SUPPOTfS Review Issues List I
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| : 11. Ebasco Cable Tray Hanger Calculations:
| |
| CTH 1102, Revision 0 CTH 1-121, Revision O CTH 1125, Revision 0
| |
| : 12. Communications Report between G. Ashley, et al (Impell); J.
| |
| Russ, et al (Cygna); R. Alexandru, et. al. (Ebarco); and S.
| |
| Harrison, et al (TU Electric), dated February 13,1987,11:30 a.m.
| |
| : 13. AISC, "Specifications for the Design, Fabrication and Erection of Structural Steel for Buildings",7th Edition
| |
| : 14. American Welding Society, AWS DL1-79, "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 i Computer Program", Revision 2 !
| |
| l
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| : 17. Communicaticas Report between R. Wheaton, et al (Impell); J.
| |
| Muffett, et al (TU Electric); and N. Williams, et al (Cygna), dated March 6,1987
| |
| : 18. Transcripts of the Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna, Ebasco, Impell, JBA and SWEC held at the CPSES Site, May 19, 1987
| |
| : 19. Impell Report IM T-0210-040 238, "Joint Impell/Ebasco Approach Toward Design Verification of Ip;ccessible Attributes", dated May 15,1987
| |
| : 20. Impell Report IM P-003, "Analysis of Welds Connecting Base Angles to Embedded Plates", Revision 0
| |
| : 21. Impell Report IM P-005, "Evaluation of Composite T channel Stitch Welds for Torsional Stresses", Revision 1 WL A 11lllllllIl111tllll11111111lll TU Electric Comanche Peak Steam Electric Station Independent Assessment Program - All Phases Job No. 84056 Revision 15 TUE\84056\RIl 2. MAN wsw
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| . _ . _ - . . , , , _ . .~.._. ._ _... _ _ - ..,_.. _ _ .-. _ . . . , _ . . . - . _ . _ _ - . _ .
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| 07/09/88 Revision 15 Page 90 CABLE TRAY SUPPORTS Review Issues List
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| : 22. Ebasco Report EB-T-3029, Attachment 6, "Weld Base Metal Evaluation", dated May 15, 1987
| |
| : 23. Communications Report between P. Harrison, et al (Ebasco); and W. Horstman, et al (Cygna), dated June 231987, 2:15 p.m.
| |
| : 24. Communications Report between G. Ashley (Impell); S. Harrison (TU Electric); and W. Horstman et al (Cygna), dated May 13, 1987, 3:30 p.m.
| |
| : 25. Communications Report between G. Ashley (Impell); S. Harrison (TU Electric); and W. Horstman et al (Cygna), dated May 14, 1937, 2:30 p.m.
| |
| : 26. Communications Report between P. Harrison et al (Ebasco) and W.
| |
| Horstman et al (Cygna) dated June 22,1987, 2.00 p.m.
| |
| : 27. Communications Report between P. Harrison and F. Hettinger )
| |
| (Ebosco); S. Harrison and J. Nandi (TU Electric); and J. Russ and N. Williams (Cygna), dated July 13,1987, 7:00 a.m.
| |
| 2R Communications Report between P. Harrison et al (Ebasco); S.
| |
| Harrison (TU Electric); and B. Shakibnia, et al (Cygna), dated July 14,1987.1030 a.m.
| |
| : 29. Ebasco Response EB-T-3256, "Ebasco's Response to Cygna's Generic Questions on Weld Base Metal Overstress", dated July 1, 1987
| |
| : 30. Impell Report IM P 016, "Evaluation of Weld Eccentricity Between Member and Weld Plane", Revision 0
| |
| : 31. Impell Calculation M-59, ' Tee Channel Stitch Welds and Web Crippling", Revision 3
| |
| : 32. Ebasco Response EB T-3426, "Base Metal Damage in Thermo-lagged Supports", dated August 27,1%7
| |
| : 33. Communications Report between P. Harrison et al (Ebasco) and J.
| |
| Russ et al (Cygna), dated September 8,1987,11:30 a.m.
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| ML L A TU Electric Comanche Peak Steam Electric Station Independent Assessment Program All Phases 111111111111111111111111111111 Job No. 84056 Revision 15 TUE\84056\RIL 2. MAN mm
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| -. . . - . _ _~ _ _ . . . . . . _ _ _ . . . _ _ . _ _ . . . . . _ _ . . . . _ _ _ . , . . _ . _ . , . . , _ . . - _ _ . _ . _ . _ .
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| 07/09/88 Revision 15 Page 91 CABLE TRAY SUPPORTS Review Issues List
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| : 34. Communications Report between SJ. Chen et al (Ebasco) and J.
| |
| Russ et al (Cygna), dated September 24,1987, 200 p.m.
| |
| : 35. Ebasco Calculation, "Commanche Peak SES Cable Tray Hanger Volume 1", Book 20, Section 3, "Inaccessible Attributes !
| |
| Calculation for Weld Metal"
| |
| : 36. Communications Report between S. Harrison (TU Electric);
| |
| P. Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al l I
| |
| (Cygna), dated October 12,1987, 9.30 a.m.
| |
| : 37. Communications Report between S. Harrison (TU Electric); P.
| |
| Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated November 17,1987, 3:00 p.m.
| |
| : 38. Communications Report between S. Harrison (TU Electric); P.
| |
| Harrison et al (Ebasco); G. Ashley et al (Impell); and J. Russ et
| |
| , al (Cygna), dated November 19,1987, 9.20 a.m.
| |
| : 39. Communications Report between S. Harrison (TU Electric); P.
| |
| Harrison et al (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated January 8,1988, 290 p.m.
| |
| : 40. Communications Report between S. Harrison (TU Electric); R.
| |
| Alexandru et al (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated January 18,1988, 9d0 a.m.
| |
| 4L Communications Report between S. Harrison (TU Electric); P.
| |
| Harrison et al (Ebasco); G. Ashley et al Impell); and J. Russ et al (Cygna), dated January 27,1988,1000 (a.m.
| |
| : 42. Communications Report between S. Harrison (TU Electric); R.
| |
| Alexandru et al (Ebasco); G. Ashley et al (Impell); and J. Russ et ,
| |
| al (Cygna), dated March 17,1988, 9:00 a.m.
| |
| : 43. Communications Report between S. Harrison (TU Electric); R.
| |
| Alexandru et al (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated March 18,1988,1000 a.m.
| |
| I TU Electric Comanche Peak Steam Electric Station Ob JL A Independent Assessment Program - All Phases lllIIl11lll1111111lllI11111ll1 Job No. 84056 Revision 15 TUE\M056\RIL-2. MAN wsw
| |
| | |
| I l
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| 07/09/88 l Revision 15 l Page 92 i l
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| l CABLE TRAY SUPPORTS l Review Issues List
| |
| : 44. Ebasco Calculation, "Commanche Peak SES Cable Tray Hanger l Volume 1", Book 20, Section 2.4: "Statistical Weld Related Studies," Revision 2
| |
| : 45. Communications Report between S. Harrison et al (TU Electric);
| |
| P. Harrison (Ebasco); and J. Russ et al (Cygna), dated March 4, 1988,1000 a.m.
| |
| Summary: Cygna has noted the following discrepancies in the weld designs for I cable tray supports.
| |
| A. Weld Details Not Shown on Design Drawings The design drawings are missing the weld details for several support types as described in Reference 1, Attachment C.
| |
| B. Weld Size Discrepancy between Design and Assembly Drawings Per discussions with Gibbs & HillfrUGCO (References 2,3,4 and 5), Cygna has noted that the weld sizes shown on the assembly drawmgs 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 require a partial penetration groove weld at the gusset plate / beam i connection. The design calculations did not consider the i eccentric load transfer from the brace member. The eccentricity of the brace loads results in a weld stress in excess of the allowable. l
| |
| : 2. Weld designs for the lap joints between channels and tetween the base angle and attached channel did not consider the eccentricity between the applied loads from the connecting members and the plane of the weld.
| |
| TU Electric Comanche Peak Steam Electric Station Jt A Independent Assessment Program - All Phases 1111lllll11llll1lll11111llllll Job No. 84056 Revision 15 TUE\84056\RIl 2. MAN mm
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| 1 1
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| 07/09/88 Revision 15 Page 93 CABLE TRAY SUPPORTS Review Issues List 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 calculations. Gibbs & Hill's weld designs assumed that the full weld throat would be developec without considering the thickness of the connected member. For example, the weld size for support designs employing C6 x 82 channels with a fillet weld crossing the web of the channel is limited to the 0.2 inch web thickness. Gibbs &
| |
| Hill designs specified a 5/16" fillet weld size and did not reduce j the throat to account for the minimum material thickness. Cases where this may be a problem include: Details E, F, G, H, J and K on Gibbs & Hill Drawing 2323-E1060101-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.
| |
| E. Minimum Weld Lengths 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 and k = distance from i back of angle leg to end of fillet. However, because of the j existence of the curve at the angle toe with radius, r ;
| |
| (approximately equal to one-half the leg thickness), the actual weld length is 1 k r.
| |
| F. Minimum Weld Size Requirements Table L17.5 of the AISC Specifications (Reference 13) specifies ,
| |
| the minimum weld sizes to be used in connection 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 DL1 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 700 F is required. For WA TU Electric Comanche Peak Steam Electric Station L Independent Assessment Program All Phases 111111111lll;llllll1111111ll11 Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN mm
| |
| | |
| 07/09/88 Revision 15 Page 94 CABLE TRAY SUPPORTS Review Issues List material greater than 3/4", but less than 1-1/2" thick, a preheat temperature of 1500 F is required.
| |
| Within Cygna's review scope, a minimum of eight supports do not meet the minimum weld size requirements of AISC.
| |
| G. Intermittent Fillet Welds l Several cable tray support designs employ composite sections (e.g. ,
| |
| SP-7 with brace, Detail 11 on drawing 232MM)905, etc.) which )
| |
| are joined using intermittent fillet welds. 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 torsion.
| |
| H. Base Angles Welded to Embedded Plates Cable tray supports can be attached to embedded plates by providing a fillet weld along the toe and heel of the base angle as a substitute for the required anchor bolts (DCA 3423, Revision j 1). The CVC for this DCA indicates that calculations were not required in the design verification of this DCA.
| |
| I. Partial Penetration Groove Weld Qualification. l See Item I in Response section below. l Response: A. The design verification is based on the as-built weld sizes and configurations per Reference 7, Section III.2 for Ebasco and Reference 9, Sections 3.0 and 4.3 for Impelt The approach to be used for inaccessible welds is described in Reference 19.
| |
| Ebasco's weld related studies are contained in References 35 and 44 and are summarized in Reference 32. The studies were concerned with the development of reduction factors for fillet welds and an evaluation of base metal defects. Cygna's review of weld reduction factors found Ebasco's approach to be acceptable. During review of Ebasco's evaluation of base metal defects, Cygna requested clarification of the sample size used in 4
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| Mk 111111111111111111111111111111 A
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| TU Electric Comanche Peak Steam Electric Station Independent Assessment Program - All Phases Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN mm
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| - - - - . . . . . . . - , . - ,- - .,, , , . . - . - , , - , - - , - - , , , - _ . - - . , . . - - ~ . . , - - . , . , . - - - . - - - - . . , - .
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| 1 07/09/88 Revision 15 Page 95 J CABLE TRAY SUPPORTS Review Issues List the study. As a result of these questions, Ebasco was able to show that only 35 supports out of a sample of 2,062 supports had welds with undercut. Given that 35 supports was less than 5% of the randomly selected sample, Ebasco concluded, and Cygna concurred, that weld undercut was not a problem.
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| (Reference 45.)
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| B. See response for Issue No.16.A.
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| C. The project design criteria (References 8 and 9) do not consistently address the consideration of eccentric loadings on the welds.
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| Based on a review of several Ebasco calculations, (Reference 11),
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| Cygna determined that Ebasco evaluates welds by obtaining end forces for the member attached to the 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.
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| 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.
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| To justify their methodology, as indicated in Reference 25, Impell provided calculation M 12 (Reference 30), Appendix I, for Cygna review. In this calculation, Impell evaluated the welds on a random sample of 60 supports. The results showed an average increase in weld interaction of 3% when eccentricities were considerea. Three categories of welds were evaluated:
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| Category 1: Weld between tier and post.
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| Category 2: Weld between post and base angle.
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| Category 3: Weld between bracing and post.
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| The sample included thirty welds in Categories 1 and 2 which showed an increase in interaction ratio of less than 1% The welds in Category 3 showed a maximum increase of 16.7%
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| However, this large increase did not result in any weld overstresses, since all of the original interaction ratios were less than 0.6.
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| MA 111lllll1lll111lll111111111111 TU Electric Comanche Peak Steam Electric Station Independent Assessment Program - All Phases Job No. 84056 Revision 15 TUE\84056\RII 2. MAN mm
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| . . . - - , , _ . . - , _ , . . _ . _ _ . . . _ . . . , - . . - - . - . - . ~ _ - . . . - - - - . _ - ~ . . . - . . . . . . , . - - - ~ . - - .
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| 07/09/88 Revision 15 Page %
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| CABLE TRAY SUPPORN Review Tamen List In Impell Calculation M-12, Appendix H, Revision 3, Impell evaluated the eccentricity of the weld between the outof-plane bracing and post members. A total of 46 supports were evaluated in this category. Significant increases in the weld stress interaction ratio were noted; however, the revised interaction ratios, after considering the eccentricity, were less than 1.0 in all sample cases.
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| Based on above results it was concluded that neglecting the eccentricity in welded connection would not have a significant effect on the design validation process.
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| 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 43 states that Impell will check the base metal shear stresses when an allowable stress greater than 21 ksi is used for fillet welds. Cygne
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| , 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.
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| In Reference 10, Impell indicated that Reference 9 will be revised to require checking using the thickness of the thinner part joinec. Ebasco provided a report summarizing the approach used to evaluate the base metal shear stresses (Reference 22). Based on comments from Cygna's review of this report, Reference 23, Ebasco revised the report. Cygna accepted the revised report.
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| E. See response for Issue No.16.A.
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| F. In Reference 15, Ebasco stated that a review of the Brown &
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| Root welding procedures indicated that low hydrogen electrodes had been used for the cable tray supports. These electrodes require a minimum preheat temperature of 500F. A review of purchase orders showed that only these electrodes were used at the CPSES site. For the low preheat temperature required, the welds used are acceptable.
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| W' L
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| litillitilllilllillllllitillli 2 048 00 TU Electric Comanche Peak Steam Electric Station Independent Assessment Program - All Phases Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN
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| l 07/09/88 Revision 15 Page 97 CABLE TRAY SUPPORTS Review Issues List G. Both consultants will evaluate the adequacy of intermittent fillet welds on the basis of the as-built weld patterns.
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| In Reference 9, Section 43 and Attachment 8, Impell requires that intermittent fillet welds be evaluated. This evaluation is "based on the capacity necessary to resist slip or movement between the two channel sections" The stresses in the weld due to torsion were not considered In response to Cygna's request for an evaluation of the shear stresses due to torsion, Impell provided Calculation M-59 and Report IM P005 (Reference 21) The (Reference response provi31)ded an evaluation of a sample of 30 cantilevered supports with Tee-channel stitch welds having an interaction ratio greater than 0.6. The increase in interaction ratio due to pure torsional and warping normal stresses was calculated For the sample, the resulting maximum interaction ratio was 0.71 for OBE and 0.68 for SSE. Therefore, the inclusion of the additional stresses will not result in support failure.
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| Ebasco evaluates the composite sections using an in-hcum computer program COMBS, (Reference 16) This program includes an evaluation of the stressec in the intermittent fillet welds which considers the shear due to flexure and the shear and normal stremes due to torsional loading.
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| H. This type of connection does not occur frequently at CPSES and individual occurrences are evaluated on a case-by-case basis by the design validation program.
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| During Cygna's audit of Ebasco's cable tray hanger design verification effort, several supports which had the base angle welded to an embedded plate were identified. The analysts of the base angles and welds for these supports were performed via finite element models representing the base angle, welds and l substrate. This approach is acceptable.
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| During the Impell audit, Cygna noted that such connections were evaluated via hand calculations. As 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 WL L A 1111llllll1111ll111lllI1ll11ll TU Electric Comanche Peak Steam Electric Station Independent Assessment Program - All Phases Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN 20d4 00
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| __ _ _ , _ __ _. . _ - . _ _ _ ,_ _ ..,._._ . ., .._.._... .,__ ,_ -__.__ ,_ - _.m
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| 07/09/88 Revision 15 Page 98 CABLE TRAY SUPPORTS Review Issues List effect of the outstanding leg of the base angle or the location of the applied load with respect to the centroid of the weld pattern.
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| Impell provided a study, Reference 20, in response to Cygna's l concerns. Cygna's concerns were satisfactorily resolved.
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| I. In certain cable tray support installations, partial penetration groove welds are used to attach gusset plates to the support members. Cygna asked for discussion of the evaluation methods used in the cable tray support design validation program. Ebasco provided information on the method used for the partial penetration groove welds used in the cable tray supports. The evaluation considers both tne effective throat to be used when calculating weld stress as well as the qualification of the actual weld joint. The latter was accomplished by fabricating several sample weld joints for testing (Reference 26)
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| The test configuration is in the form of a tee-joint in which the stem has a prepared face which butts against another plate to form a tee. Two preparation angles were used, with the edge of the stem butting the other plate beveled at 300 and 450 angles.
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| These configurations were selected to cover the common joints of this type found at CPSES, which include the connection between the gusset plate from a longitudinal brace to the back of a tier web such as the support types with Gibbs & Hill designation "SP-7 with brace."
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| Cygna noted that certain support types allowed a range of brace slopes that are not fully covered by the Ebasco qualification.
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| Ebasco was requested to provide an evaluation for additional brace slopes.
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| Subsequent to above dimension, Ebasco performed additional partial penetration weld testing using a slope equal to the worst case slopes found at CPSES. Cygna reviewed the testing program results and noted reductions in allowable weld capacities. The results were acceptable (References 38 and 40) l Status: A. Closed.
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| B. See status for Issue No.16.A.
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| Mk A 11lll111lll1111111111111111111 TU Electric Comanche Peak Steam Electric Station Independent Assessment Program - All Phases Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN um m
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| _ - - . _ . _ _ _ , _ . . . . _ . . . _ , . _ _ . _ . _ , . _ . _ . - - , ~ . . _ _ _ . . _ . . . . . - ~ . . , _ _ . . _ , , , . , , . . . ,..-- ..._..
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| 1 07/09/88 Revision 15 Page 99 CABLE TRAY SUPPORTS Review Issues List C. Closed .
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| 1 D. Closed l I
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| E. See status for Issue No.16.A.
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| F. Closed l G. Closed i H. Closed l I. Closed l
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| TU Electric Comanche Peak Steam Electric Station j k k A Independent Assessment Program - All Phases '
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| 07/09/88 Revision 15 Page 100 CABLE TRAY SUPPORTS Review Issues List
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| : 17. Embedded Plate Desien
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| ==References:==
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| L N.H. Williams (Cygna) letter to J.B. George (TUGCO), "Cable Tray l Support Review Questions" 84056.041, dated February 12, 1985, Attachment A, Question No.1
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| : 2. LM. Popplewell (TUGCO) letter to N.H. Williams (Cygna) dated April 19,1984, page 11
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| : 3. Communications Report between N. Williams, J. Russ, W. Horstman (Cygna); R. Kissinger, T. Keiss (TUGCO); and B. Bhujang, P.
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| Huang, S. Chang (Gibbs & Hill), dated September 15, 1984
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| : 4. Communications Report between M. Warner (TUGCO) and N.
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| Williams, J. Minichiello, J. Russ (Cygna), dated February 27, 1985
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| : 5. Gibbs & Hill Calculation Binder 2323-SCS-146C, Set 4, Sheet 3-9, 21
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| : 6. Gibbs & Hill Drawing 2323-S-0919, Revision 3 l 1
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| : 7. Brown & Root Installation Procedure CCP-45, "Permanent and Temporary Attachments to Weld Plates," Revision 1, August 18, 1980.
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| : 8. Gibbs & Hill Specification 2323-SS-30, Appendix 4, "Design Criteria For Embedded Plate Strips," Revision 1
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| : 9. N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO), "Cable Tray / Conduit Support Review Questions," 84056.089, dated October 21,1985
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| : 10. Transcripts of the Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna, Ebasco and Impell at the CPSES Site, January 26 and 27,1987.
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| : 11. Transcripts of the Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna, Ebasco, Impell, JBA and SWEC held at the CPSES Site, May 19, 1987.
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| TU Electric Comanche Peak Steam Electric Station a Al Independent Assessment Program - All Phases 11i11llllll11111111111111lllll Job No. 84056 Revision 15 TUE\S4056\RIL-2. MAN wsw
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| 07/09/88 l Revision 15 Page 101 CABLE TRAY SUPPORTS Review Issues List
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| : 12. Cygna Energy Services, "Civil / Structural Review Issues List,"
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| Revision 0, dated July 21, 1987.
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| Summary: A. Prying Action on Nelson Studs Gibbs & Hill performed capacity calculations for cable tray support attachments to embedded strip plates. Cygn,a'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.
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| 1 B. Stiffening Requirements for Moment Attachments Questions from Cygnc's pipe support reviewers and cable tray reviewers on the stiffening requirements for embedded plate moment connections elicited conflicting responses from TUGCO personnel. The pipe support 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 ,
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| 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).
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| Cygna has requested any documents which address the corrective action associated with the issuance of Specification,2323-SS-30 (Reference 9).
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| D. Inspection Requirements for Attachment Spacing 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 i discussion between Cygna and TUGCO (Reference 4), it was determined that even though the installation procedure requires this separation, the inspection procedures for cable tray supports TU Electric Comanche Peak Steam Electric Station "L A' Independent Assessment Program - All Phases ll1111lll111111111lllll11lllll Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN em w
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| 07/09/88 Revision 15 Page 102 CABLE TRAY SUPPORTS Review Issues List do not require an inspection of this attribute.
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| Cygna walkdowns noted several instances where the separation between attachments to embedded plates were less than 12" (See Pipe Support Review Issue No. 9). Cygna is concerned that the lack of control of attachment spacing may have an impact on the design adequacy of the attachments.
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| E. Installation of Details E, F, F, G, and H on Embedded Plates Reference 5 is the design calculation for the installation of Support Details E,F,G, and H (Gibbs & Hill Drawing 2323-E10601-01-S) on embec'ded strip plates. A maximum tributary tray span of 7'-6" is used in these calculations. Note 9 on Reference 6 statu-The supports will have a location tolerance of 12" in the direction parallel to the tray and 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.
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| Supports installed in accordance with this drawing note may have ,
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| to resist loads due to a 9'-0" tributary span, l'-6" greater than :
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| the design tributary span.
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| F. Spacing Requirements Between Embedded Plates and Concrete Anchors 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 l applied to situations whce the expansion anchor is installed in a surface perpendi.ular to the embedded plate.
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| TU Electric Comanche Peak Steam Electric Station
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| ' L A Independent Assessment Program - All Phases 1111!I1111lll11111111lllllllll Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN mx
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| l 07/09/88 Revision 15 Page 103 CABLE TRAY SUPPORTS Review Issues List Respon;e: The evaluation of embedded plates at CPSES is covered under the Civil / Structural Corrective Action Program. The cable tray support issues relating to embedded plates are now covered in the Civil / Structural Review Issues List (Reference 12).
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| I A. See Reference 12, Civil / Structural Review Issue No. 4 j B. See Reference 12, Civil / Structural Review Issue No. 4 C. See Reference 12, Civil / Structural Review Issue No. 4 ;
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| D. See Reference 12, Civil / Structural Review Issue No. 2 l l
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| E. Attachment loads from cable tray supports are calculated using ,
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| as-built span data. These attaclanent loads are transmitted to l SWEC for use in the embedded plate evaluations. <
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| I F. See Reference 12, Civil /St.mictural Review Issue No. 2 Status: A. See Reference 12, Civil / Structural Review Issue No. 4 B. See Reference 12, Civil / Structural Review Issue No. 4 C. See Reference 12, Civil / Structural Review Issue No. 4 j D. See Reference 12, Civil / Structural Review Issue No. 2 E. See Reference 12, Civil / Structural Review Issue No. 4 F. See Reference 12, Civil / Structural Review Yssue No. 2 l
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| TU Electric Comanche Peak Steam Electric Station
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| ' bJ' ' Independent Assessment Program - All Phases
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| 07/09/88 Revision 15 Page 104 CABLE TRAY SUPPORTS Review Issues List
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| : 18. Cable Trr,v Clamos
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| ==References:==
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| L Gibbs & Hill Drawing 2323-S-0902, Revision 5
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| : 2. TUGCO Drawing TNE-S10902 02, Revision CP-2
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| : 3. Communication Report between T. Keiss (TUGCO) and W.
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| Horstman (Cygna), dated November 15, 1984
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| : 4. Ebssco Instruction SAG.CP34, "General Instructions for Cable Tray Hanger Analysis for Comanche Peak SES Nos.1 and 2,"
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| Revision 11
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| : 5. Ebasco Procedure SAG.CP11, "System Analysis for Cable Tray and Hanger Assembly for CPSES Units 1 and 2," Revision 4
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| : 6. Impell Calculation M 10, "Clip Angle Stiffness" Revision 3
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| : 7. Impell Calculation M 19, "Clip Stiffness Production Values" Revision 2 8 Impell Report 09-02104)017, "CPSES Cable Tray System Analysisfrest Correlation," Revision 0
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| : 9. Impell Instruction PI02, "Dynamic Analysis of Cable Tray Systems," Revision 6
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| : 10. Impell Calculation M 28, "Justification for Clip Modeling Procedures," Revision 6 IL Impell Instruction PI11, "Cable Tray, System Analysis and Qualification Closecut" Revision 3
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| : 12. Ebasco Calculation, "Comanche Peak SES Cable Tray Hanger Volume I," Book 2J, "CTH Clamp Qualification, Methodology and Development," Revision 1
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| : 13. Ebasco Report SAG. CP-19, "Design Criteria and Procedures for Design Verification of Cable Tray Clamps" Revision 5 TU Electric
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| >q( ,, , Comanche Peak Steam Electric Station IIlllilillilllllilitilllililli Independent Assessment Program - All Phases Job No. 84056 Revision 15 TUE\84056\RIl 2. MAN
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| 07/09/88 Revision 15 Page 105 CABLE TRAY SUPPORTS Review Issues List
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| : 14. Communications Report between F. Hettinger et al (Ebasco); S.
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| Harrison (TU Electric); and B. Shakibnia et al (Cygna), dated July 14,1987,10:10 a.m.
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| : 15. CCL Test Report, Report No. A-717 86, dated January 27, 1988 and Report No. A-721-86, dated July 13, 1986
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| : 16. ASME "Boiler and Pressure Vessel Code," Section III, Subsection NF 3282.4
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| : 17. Impell Instruction PI.06, "Design Verification of Cable Treys and Tray Clamps" Revision 2 l
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| : 18. Communications Report between P. Harrison et al (Ebasco); S.
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| Harrison (TU Electric); and W. Horstman et al (Cygna), dated June 26,1987,1:00 p.m.
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| : 19. Communications Report between S. Harrison et al (TU Electric);
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| P. Harrison (Ebasco); G. Ashley et al (Impell); ;nd J. Russ et al (Cygna), dated December 9,19 7,1:30 p.m. j
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| : 20. Communications Report between S. Harrison et al (TU Electric);
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| P. Harrison et al (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated December 10,1987, 9:20 a.m.
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| : 21. Communications Report between G. Ashley et al (Impell); P.
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| Harrison et al (Ebasco); and J. Russ et al (Cygna), dated December 10,1987,1.00 p.m.
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| : 22. Communications Report between P. Harrison et al (Ebasco); S.
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| Harrison et al (TU Electric); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated December 18,1987,12:30 p.m.
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| : 23. Communications Report between S. Harrison et al (TU Electric);
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| R. Alexander et al (Ebasco); G. Ashley (Impell); and J. Russ et al l (Cygna), dated January 6,1988, 9.20 a.m. j
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| : 24. Communications Report between S. Harrison et 81 (TU Electric) and J. Russ et al (Cygna), dated January 8,1988, 2.00 p.rn.
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| TU Electric 4g,, Comanche Peak Steam Electric Station Independent Assessment Program - All Phases IIllililillifilillitilitilliti Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN
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| )
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| l 07/09/88 Revision 15 Page 106 CABLE TRAY SUPPORTS Review Issues List 1 l
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| : 25. Communications Report between S. Harrison et al (TU Electric);
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| P. Harrison et al basco); G. Ashley et al Gmpell); and J. Russ !
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| et al (Cygna), dat January 19,1988, 2:20 p.m.
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| : 26. Communications Report between S. Harrison et al (TU 1lectric);
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| P. Harrison et al (Ebasco); R. Kaczkowski et al (Impell); and J.
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| Russ et al (Cygna), dated January 21,1988, 2:30 p.m.
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| : 27. Communications Report between S. Harrison et al (TU Electric); j P. Harrison et al (Ebasco); G. Ashley et al (Impell); and J. Russ -
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| et al (Cygna), dated January 25,1988,1:50 p.m.
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| : 28. Communications Report between S. Harrison et al (TU Electiic);
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| P. Harrison et al (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated January 27,1988,1000 a.m.
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| : 29. Communications Report between J. Veikos et al (Ebasco) and B.
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| Shakibnia (Cygna), dated February 4,1988, 930 a.m.
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| : 30. Communications Report between P. Harrt , et al (Ebasco); S.
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| Harrison (TU Electric); G. Ashley et al :m 411); R. Nickell (AST); and J. Russ et al (Cygna), dated brut.ry 5, 1988, 10 0 0 !
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| a.m.
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| : 31. Communications Report between J. Veikos (Ebasco) and B.
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| Shakibnia (Cygna), dated February 5,1988,10.30 a.m.
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| : 32. Communications Report between J. Veikos et al (Ebasco) and B.
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| Shakibnia (Cygna), dated February 5,1988, 2:15 p.m.
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| : 33. Communications Report between R. Kazcowski (Impell) and W.
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| Horstman (Cygna), dated February 17,1988,1100 a.m.
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| : 34. Communications Report between S. Harrison (I'U Ele,:tric); P.
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| Harrison (Ebasco); R. Kazcowski (Impell); and W. Horstman (Cygna), dated February 24,1988, 9:00 a.m.
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| : 35. Communications Report betweet S. Harrison (TU Electric); G.
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| Ashley (Impell); P. Harrison et al (Ebasco); and J. Russ et al (Cygna), dated March 7,1988,12:00 p.m. ;
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| i 4
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| TU Electric g Comanche Peak Steam Electric Station flilllilililillilifililllilli Independent Assessment Psogram All Phases ,
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| Job No. 84056 Revision 15 TUE\84056\RIl 2. MAN ;
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| : 36. Communications Report between S. Harrison et al (TU Electric);
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| P. Harrison et al (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated March 17,1988, 900 a.m.
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| : 37. Communications Report between S. Harrisen et al (TU Electeic);
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| P. Harrison et al (Ebasco); G. Ashley et al (Impell); and J. Rus et al (Cygna), dated March 17,1988,11:15 a.m.
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| : 38. Communications Report between S. Harrison et al (TU Electric);
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| P. Harrison et al (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated March 18,1988,10.20 a.m.
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| : 39. Communications Report between S. Harrisen (TU Ele tric); P.
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| Harrison et al (Ebasco); G. Ashley (Impell); ud W.11 >rstman et al (Cygna), dated March 22,1988,12:20 p.m.
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| : 40. Communications Report between S. Harrison ('l?) Ele:tric); G.
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| Ashley (Impell); and J. Russ et al (Cygna), date/ Mar:h 23, 1988, 9:00 a.m.
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| : 41. Communications Report between S. Harrison (TU Electric); G.
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| Ashely (Impell);and J. Russ (Cygna), dated March 30, 1988, 7:15 a.m.
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| : 42. Impell Calculation M-51, "Clamp Allowables from Test Data,"
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| Revishn 5.
| |
| : 43. Impell Report IM-P-020, "Respor.sc to Evaluation of Longitudinal Load at Tran verse Supports," Revision 1.
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| : 44. Communications Report between S. Harrison (TU Electric) and J.
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| Russ et al (Cygna), dated March 25,1983, 8:35 a.m.
| |
| Summary: Two general categories of cable tray clamps are used at CPSES.
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| "Friction" type clamps are installed on transverse type supports (e.g.,
| |
| A1, B1, SP-7, etc.) These clamps are assumed to provide vertical and horizomal transverse load transfer. "Heavy duty" clamps are installed on longitudinal trapeze supoorts (e.g., L-A1, L-B1, etc.), three-way supports (e.g., SP-7 with brace, Detail 8 on drawing 2323-S-0903, etc.),
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| a and transverse supports, where interferences (e.g, tray splice plates, fittin , etc.) prevent the installation of friction type clamps. Heavy TU Electric q Comanche Peak Steam Electric Station )
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| Independent Assessment Progam - All Phases l I
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| IllllilllililllillIlllillilliJob No. 84056 Revisicn 15 TUE\84056\RIL-2.Mf.N
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| l CABLE TRAY SUPPORTS Review Issues List l
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| duty clamps are designed to transfer vertical, horizontal transverse, j and longitudinal tray loads to the cable tray support beam. ;
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| References 1 and 2; DCA 3464, Revision 23; DCA 6299, Revision 7; and l DCA 20331, Revision 0 provide clamp configuration details. l 1
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| In addition to the indicated load transfers between trays and supports, i Gibbs & Hill has assumed other load transfer mechanisms in onder to justify behavioral assumptions made in the support designs.
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| A. Friction Type Clamps l For "friction" type clamps, the following assumptions have been i made in order to justify the system concept (See Issue No.10) l 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.)
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| 1 o The trays will provide lateral bracing to the compression i flanges of the horizontal beams (See Issue No. 24) l o The trays will provide out-of plane bracing to supports to !
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| prevent frame translation which would result in increased l anchor bolt tensile loads (See Issue No. 3) i 1
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| o The cabic trays will transfer out of-plane inertial loads from transverse supports to longitudinal supports on the same tray run. (See Issue No. 6.)
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| o The development of minor axis bending moment in the beams due to the horizontal eccentricity between the beam neutral axis and the clamp bolt is minimized by a bending moment in the cable tray (See Issue No. 24) o For vertical loading, the development of torsion in the beam due to the eccentricity between the clamp location and the beam shear center is prevented by flexure of the cable tray.
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| This assumes a full moment fixity between the tray and the support beam (See Issue No. 24)
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| TU Electric Comanclie Peak Steam Electric Station
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| B. Heavy Duty Type Clamps For heavy duty clamps, all of the above assumptions are applicable. Additionally, the following assumption was made by Gibbs & Hill:
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| o The development of torsion due to longitudinal loads on three-way supports using composite beam sections (e.g., SP-7 with brace and Detail 8 on Drawing 2323-S-0903, etc.) is prevented by flexure of the cable tray. This assumes a full moment fixi between the tray and the support beam (See Issue No. 24 The asumptions described above are valid only if the clamps can provide suitable displacement and rotational compatibility between the tray and the support beam. Based on a discussion with TUGCO (Reference 3), Cygna determined that installation tolerances (Reference 2; DCA 6299, Revision 7; DCA 20331, Revision 0; and CMC 93450, Revision 4) were adopted to allow gaps between the tray side rails, the support beam, and the tray clamps. In order to provide the assumed compatibility, "friction" i type clamps must be cinched sufficiently to develep friction at the tray / beam and tray / clamp interfaces. The existence of gaps will preclude the development of the normal contact force {
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| required for frictional resistance.
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| C. Clamp Qualification This issue was raised based on the review of the cable tray support design validation program. See the Reponse Section below for a discwsion of the issue.
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| D. Clamp Stiffness Values This issue was raised based on the review of the cable tray support design validation program. See the Response section below for a discussion of the issue.
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| Response: A. The effects of the connectivity provided by friction type clamps !
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| between cable trays and transverse supports are considered in the design verification in two ways. These assumptions on TU Electric Comanche Peak Steam Electric Station
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| connectivity affect the issues regarding out of plane inertial loads, base angle rotation, effective length for compression members, etc. !
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| In all analyses performed by Impell, the clamps are assumed to provide full connectivity between the cable trays and the supports. In References 6 and 7 hnpell itas developed clamp stiffness values associated with the three translational and three rotational degrees of freedom of the tray to support connections. These stiffnesses are summarized m Section 3.2.4 of Reference 9.
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| The transmission of forces and moments between the cable tray and the cable tray support, in spite of the potentially significant gaps between the clamps and the tray, is justified based on the mterpretation of the results of a series of dynamic tests of full scale models of cable tray systems. The test results are summarized in Reference 8. Analytical justification is provided in Reference 10.
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| In a large portion of the analyses performed by Ebasco, the friction type clamps are assumed to be incapable of 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 l modeling guidelines. I In light of the connectivity assumption used by Impell, and in l order to achieve consistency in the desigu validation program, ;
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| Ebasco evaluated the impact of the differences beWeen tle 1 assumptions used by the two consultants. In accordance with Attachment Z of Reference 4, Ebasco is reevaluating cable tray supports analyzed by the ESM to de'.crmine the impact of tray / support connectivity on the supports previously qualified assuming no connectivity. Similarly, for supports analyzed by RSM, all previously analyzed systems will be reanalyzed, including tray / support connectivity, to evaluate the impact of this change in assumptions.
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| l TU Electric Comanche Peak Steam Electric Station
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| ' b2' A .
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| Independent Assessment Program - All Phases lililililllilitillitilllitml Job No. 84056 Revision 15 TUE\84056\RII 2. MAN
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| CABLE TRAY SUPPORTS Review Issues List Therefore, the current cable tray support design verification -
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| effort asumes connectivity between the tray and the support and ,
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| thus, includes the same load transfer mechanisms employed by Gibbs & Hill B. For supports anal by the equivalent static method, Ebasco assumes that the vy duty clamps provide three directional force transfer without any moment transfer (Reference 4, Attachment B2) Thus, the heavy duty clamps do not reduce the torsion or bending moments due to the eccentricities between the cable tray and the support.
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| For cable tray supports included in response spectrum analyses (Ebasco's RSM models and Impell's system models), heavy duty clamps are assumed to provide force and moment transfer between the tray and the support. The clamps are modeled as linear elastic spring elements having the rotational and translational stiffness properties calculated in References 6 and 7.
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| These values are documented in References 5 and 9.
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| C. Cable tray clamps are evaluated for the load transfer between :
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| the cable trays and the su > port members. The allowable loads ;
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| and load interaction equat.ons are based on analysis in combination with the results of clamp capacity testing performed ,
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| by CCL, Reference 15. Ebasco performs clary, quahfication in accordance with the procedures provided in References 12 and
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| : 13. Similar procedures arc provided in Refeience 17 for Impell.
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| l The clamp test program included unidirectional static testing to I determine clamp ultimate capacity, multidirectional static testing l to determine the interaction relationship for combined loading i and cyclic (dynamic) testing to determine the degradation of !
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| clamp stiffness and capacity under repeated load cycles, representing seismic loadin;. The results of these tests were used by Ebasco and Impel, to develap their respective clamp qualificatiui procedures. Cygna has reviewed the test report, the qualification procedures and the associated back-up calculations.
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| The clamp qualification procedures provide allowable loads for various clamp types. Vertical and transverse load capacities are provided for friction type clamps (Types A, C, and G) Three TU Electric y ,
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| Comanche Peak Steam Electric Station Independent Assessment Program - All Phases IIllilililllilliidilllil!IllJob No. 84056 Revision 15 TUE\84056\RIL-2. MAN i
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| directional load capacities are provided for heavy duty type l clamps (all other type designations). Since clamps are considered l to restst forces and moments when included in the system (RSM) analyses, the resulting moments are transformed into equivalent couples and added to the directly calculated forces Cygna's review of the clamp qualification resulted in several comments and concerns which were discussed and resolved with Ebasco and l Impell. j 1r Ebasco's Application of ASME Loading Rating.
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| In the development of allowable loads for clamps, Ebasco, in Reference 14, used the ultimate load capacities from the ,
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| static clamp testing and the load rating requirements of l ASME B&PV, Section III, Subsection NF3282.4:
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| ' oad Rating =
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| l x Fe SS- x 0.5 1
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| Tu u Safety Factor = 1" 1 Load Rating Where: Tu= i Ultimate Test Load ;
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| S = Allowable Material Stress l l
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| Su = Ultimate Material Tensile Stress i Fc = Capacity Factor = 1.0 for OBE 1.5 for SSE j Howe.ver, Ebasco substituted 'he material yield stress for Su and the allowable shest stress for S.
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| In Reference 14, Ebasco provided justifkation for the noted substitutions in the load rating equation. The yielo stress was used for Sus ince the failure mode for the tricticn type clamps is generally through disengagement from the tray siderail This generally occurs at the yield of the clamp l rather than the ultimate tensile strength. The value of the j TU Electric l Comanche Peak Steam Efectric Station .
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| IIlllillilillilliiIlllillilli Independent Assessment Program - All Phases !
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| Job No. 84056 Revision 15 TUE\84056\RIL 2. MAN ,
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| 07/09/88 Revision 15 Page 113 CABLE TRAY SUPPORTS Review Issues List allowable bending stress is used for S. For heavy duty clamps, the failure mode is generally shear failure in the clamp bolts. The shear yield stress is used for Su in this case and the allowable shear stress for S.
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| : 2. Consideration of Load Component Mz As dicussed above, the moment components of clamp loads from system models are resolved into force couples. For friction type clamps, this is done by considering the three momen's in Impell's evaluation, but only for two by Ebasco.
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| The Mz component, corresponding to minor axis bending of the cable tray and torsion of the support tier, is not considered by Ebasco Based on several discussions between Impell, Ebasco and Cygna, it was determined that due to the presence of gaps between the tray and clamp, and the low rotational stiffness associated with the mnent component, Mz could be ceglected by both Impell and Ebasco.
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| In support of this assumption, Impel! prepared an evaluation, Attachment F to Reference 10, to consider the impact of releasing Mz. The effects on the cable tray moments, chmp loads, support loads and system behavior were addressed.
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| The only significant change note was in the torsion in the support tier. However, since the stresses due to torsion (i.e. direct shear and warping stresses) provide a small contribution to the total member stress interaction ratio, the increase in torsion will not impact the support qualification.
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| : 3. Consideration of Longitudinal Loads on Friction Type Clamps As discussed under the response to Issue No.16.A, longitudinal connectivity between the cable trays and supports is considered for supports using friction type clamps. Though a longitudinal load is calculated, it was not initially considered in the qualification of friction ty.e clamps (Types A, C and G). Such clamps were eva:usted only for the vertical and transverse loads.
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| TU Electric Comanche Peak Steam Electric Station M J5 ' Independent Aueaunent Program All Phases tillmitillitililllilitililli Job No. 84056 Revisioc.15 TUE\84056\RIL 2. MAN
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| l Impell and Ebasco indicated that it was not n-ry to I check the clamps for longitudinal load, since this loed was assumed to be transferrec via friction between the cable tray siderails and the top of the support tier. Cygna stated that this load tramfer method was only valid so long as the '
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| downward normal force between the tray and support was sufficient to provide frictional resistance. When subjected to vertical seismic loading, the tray may uplift, and the normal force would exist between the top of the tray and the clamp. Similarly, for horizontal seismic loading, the normal force would exist between the side of the tray and the ciamp. In these cases, the clamp would be required to resist the longitudinal loading. Cygna requested an efsluation of clamps for the longitudinal loading.
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| A report, Reference 43, calculations, Reference 42, and revisions to the clamp qualification procedures were provided to address the evaluation of friction clamps for longitudinal loading. The approach used was the some for bot' Ebasco and Impell. Longitudinal load capacities were developed for each type of friction clamp and the longitudinal load component was added to the clamp interaction ratio equation.
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| The approach used varied with clamp type.
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| : a. Clamo Tyoe A l Due to the geometry of this clamp, longitudinal loading l will result in bending between the clamp and tray siderail. The load capacity is based on she material I capacity of the clamp.
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| : b. Clamo Tvoe C Longitudinal loading is resisted by a combination of friction and binding of the clamp. The capacity is based on material strength, but is limited to the normal force times a friction coefficient. As discussed in Reference 40, both clamps, considered as a pair, are assumed to resist longitudinal loading.
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| ) c. fJamo Tyne G TU Electric Comanche Peak Steam Electric Station
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| 07/09/88 Revision 15 Page 115 CABLE TRAY SUPPORTS Review Issues List This clamp will not bend; the load transfer mechanism is solely dependent upon friction. The capacity is based on
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| ' the material strength, but limited to the applied normal force times a coefficient of friction. Initially, ImpeP proposed using a coefficient of friction equal to 039.
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| Cygna indicted that this value was too large, if the clamp test data was considered. In Reference 38, a lower value was agreed upon, based on the test results.
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| : 4. Vertical Load Capacity for Type C Clamps Type C clamps lave the lowest vertical load capacity of all friction clamps. This clamp type is assumed if the actual installed clamp type is unknown or inaccessible.
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| Under the cyclic load testing, Reference 15, Type C clamps showed significant inelastic deformation and lower ultimate capacity than the static testing. In order to account for the inelastic behavior, an evaluation was performed, using the energy balance approach, to develop an equivalent capacity for purely linear behavior. His evaluation was provided m Appendix A of Impell Calculation M-51, Revision 1 (Reference 42) Cygna reviewed this calculation and provided comments in Reference 30. Cygna was concerned over Impell's consideration of the energy balance for only one cycle of the testing and the potential that the behavior may continue to degrade, without reaching a steady state response. Irapell agreed to revise the evaluation to address Cygna's concerns. Calculatiot M 51 was revised and Appendix D was added. Impell poinL-4 out that since the cable tray system will be required to survive only one SSE during the life of CPSES, the inelastic deformationa of these clamps would not be required to continue to a steady state.
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| The response addressed the behavior during the later cycles of the cyclic testing and demonstrated that the inelastic strain was actually decreasing with each cycle. This indicates that the response is "shaking down" to a steady state response, ne energy balance approach was revised to consider the inelastic energy associated with the last cycles TU Electric Comanche Peak Steam Electric Station N b. J' ' Independent Assessment Program - All Phases l16111666lllll111lllll11lll111 Job No. 84056 Revision 15 TUE\84056\RIl 2. MAN
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| t 07/09/88 Revision 15 Page 116 CABLE TRAY SUPPORTS Review Issues List of the test, rather than the first. This resulted in a marked decrease in allowable clamp loads. Impell and Ebasco agreed to review all Type C clamps considering the reduced capacity.
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| D. As discussed in the Response for Issue No.16.B, Ebasco and Impell calculated translational and rotational stiffnesses for the cable tray clamps based on the geometric and material properties of the clamps. Based on the interpretation of the system dynamic test program results (Reference 8), Impell concluded that the calculated clamp stiffnesses were too low, resulting in ficticious response modes for th: cable trays. As a result, Impell provided instructions in PI-11, Reference 11, allowing the use of mereased clamp stiffness values in the system models. Cygna expressed concern over the use of increased clamp stiffnesses.
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| These changes may cause frequency shifts for the models, and impact the predicted response.
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| Impell provided a discussion of the system test behavior, and the results of the analytical correlation effort (Reference 8) which showed that better analysis / test correlation was achieved if the higher clamp stiffnesses were used. Based on this discussion (Reference 20), Cygna accepted the use of higher clamp stiffnesses.
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| I Status: A. Closed.
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| B. Closed.
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| C. Closed.
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| D. Closed.
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| : 19. FSAR Load Combinations
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| ==References:==
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| : 1. CPSES FSAR, Section 3A43
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| : 2. Gibbs & Hill Calculation Binder 2323-SCS-103C, Set 1, Sheets 14-19
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| : 3. Gibbs & Hill Calculation Binder 2323-SCS-103C, Set 2, Sheet 32
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| : 4. Transcripts of Cable Tray Hanger Design Verification meeting between TU Electric, Cygna, Ebasco and Impell held at the CPSES Site on January 26 and 27,1987 ,
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| S. C.R. Levine (TUGCO letter to K.C. Warapius (Impell) No.
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| TSG 19043, dated Jul 2, 1986
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| : 6. 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
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| : 7. Impell report No. 0210-040/41 IM P 006, "Effects of Thermal Loading on Cable Tray Systems" Revision 0, dated May 15, 1987
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| : 8. Impell Calculation M 27, ' Thermal Load Evaluation," Revision 4 l
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| : 9. Communications Report between S. Harrison (TU Electric);
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| P. Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated November 17,1987, 3:00 p.m.
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| : 10. Communications Report between S. Harrison et al (TU Electric),
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| G. Ashley (Impell); J. Russ et al (Cygna); and P. Harnson et al (Ebasco), dated January 6,1988, 920 a.m.
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| : 11. Communications Report between S. Harrison et al (TU Electric) and J. Russ et al (Cygna), dated January 8,1988, 2:00 p.m.
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| : 12. Communications Report between R. Kazcowski et al (Impell); and J. Russ (Cygna), dated January 12,1988,12:40 p.m.
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| : 13. Communications Report between S. Harrison (TU Electric); P.
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| Harrison (Ebasco); R. Kazcowski (Impell); and W. Horstman (Cygna), dated February 24,1988, 9:00 a.m.
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| i 07/09/88 l Revision 15 Page 118 CABLE TRAY SUPPORTS Review Issues List 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 i
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| loads are considered.
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| For supports installed in the Reactor Building;s, the loads associated l with a LOCA may be applicable, including pipe whip, jet impingement, and thermal loads. Two support types within Cygna's review were designe<* for installation in the Reactor Building, Detail A (Gibbs & i Hill Drawing 2323 El 050044-S) and Detail C (Gibbc & Hill Drawing 2323.El-050001-S). The design calculations for these supports, i
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| References 2 and 3, respectively, did not consider these additional loads. i Response: Information provided in Reference 5 indicates that ssfe shutdown cable trays identified as pipe whip or jet impingement targets have either ;
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| been relocated or shielded from the potential loads. Therefore, there l is no need to evaluate the cable trays or supportt for these loads. l In Reference 4, TU Electric indicated that cable trays do not need to ,
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| be evaluated for the thermal effects associated with normal operating temperatures and had developed a position relating to the effects of ,
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| thermal loads due to the accident temperatures on support anchorages l (Reference 7) Reference 8 is listed as the basis for Reference 7. l Cygna reviewed Impell Calculation M 27, Revision 4, which pertained to the "Thermal Load Evaluation". Cygna's review comments and acceptance are discussed in Reference 9 through Reference 13.
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| Status: Closed.
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| TU Electric ;
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| : 20. Differences Between the Installation and the Desian/ Construction Drawines without Acorooriate Documentation
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| ==References:==
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| : 1. Gibbs & Hill, Inc., Support Layout Drawing 2323 El 0713-01-S
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| : 2. Brown & Root, Inc., Fabrication Drawing FSE40159
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| : 3. American Institute of Steel Construction, Inc., "Manual of Steel Construction" 7th Edition
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| : 4. Gibbs & Hill Support Layout Drawing 2323-E1060101-S
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| : 5. Gibbs & Hill Support Layout Drawing 2323-E1470001-S
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| : 6. Gibbs & Hill Cable Tray Support Design Drawings 2323-S-0900 series
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| : 7. N.H. Williams (Cygna) letter to J.B. George (TUGCO), "Cable Tray Support Walkdown Questions," 84056.026, dated August 23, 1984
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| : 8. Communication Report between M. Warner, J. van Amerongen (TUGCO) and W. Horstman (Cygna) dated October 25, 1984
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| : 9. Communication Report between T. Webb, M. Hamburg (TUGCO) and W. Horstman (Cygna), dated October 18, 1984
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| : 10. Communication Report between M. Warner, C. Biggs (TUGCO) and W. Horstman (Cygna), dated October 10, 1984
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| : 11. Brown & Root Procedure No. CEI-20, "Installation of Hilti Drilled-In Bolts" Revision 9
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| : 12. LM. Popplewell (TUGCO) letter to N.H. Williams (Cygna),
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| "Comanche Peak Steam Electric Station Cygna Review Questions,"
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| dated September 6,1984
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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 I
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| : 14. N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO), "Cable Tray / Conduit Support Review Questions," 84056.089, dated October 21, 1985
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| : 15. Brown & Root Instruction QI-QAP-11.2-28, "Fabrication, Installation Inspections of ASME Component Supports, Classes 1, 2, and 3," Revision 29
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| : 16. Transcripts of the Cable Tray HangerDesign Verification Meeting between TU Electric, Cygna, Ebasco and Impell held at the CPSES Site on January 26 and 27,1967
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| : 17. TU Electric Procedures TNE FVM.CS.001, "Field Verification Method Unit 1 Cable Tray Hanger As Builting and Design Adequacy Verification Program", Fev. 5, July 1,1986, and TNE FVM.CS-003, "Field Verification Method Unit 2 Cable Tray Hanger As Builting and Design Adequacy Verification Program,"
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| 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
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| : 18. TU Electric, CPSES, "Generic Issues Re rt Evaluation and Resolution of Generic Technical Issues r Cable Tray Hangers",
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| Revision 2
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| : 19. Transcripts of the Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna, Ebasco, Impell, JBA and SWEC held at the CPSES Site, May 19, 1987
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| : 20. Impell Report No. IM-T 0210040-288,"Impell/Ebasco Approach Towards Design Verification of Inacccasible Attributes," dated May 15,1987 2L Cygna Energy Services, Tivil/ Structural Review Issues List" Revision 0, dated July 21, 1987 l
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| : 22. TU Electric Specification CPE-S-10.1, Revision 0 l
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| : 23. Impell Calculation M 39, "Side Rail Extension Study," Revision 1 TU Electric Comanche Peak Steam Electric Station
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| _ _ - , . _ . - . . - _ . _ _ ___ . ,_..__.___ _ ,._ _ . _._ _ __., _ ,___. _ .__ ._ , _ _ _ . ,__.._ ,._. _ .._. ~ -. _ . _ .__._ _ _
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| : 24. Communications Report between S. Harrison et al (TU Electric);
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| P. Harrison (Ebasco); G. Ashley (Impell); and J. Russ et al (Cygna), dated September 3,1987,10:00 a.m.
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| : 25. Communications Report between S. Harrison (TU Electric); P.
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| Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna); dated October 12,1987, 9:30 a.m.
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| : 26. Communications Report between S. Harrison (TU Electric);
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| P. Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated November 17,1987, 300 p.m.
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| Summary: Cygna performed walkdown inspections on 49 of the 92 supports within the Independent Assessment Program review scope. Certain discrepancies between the as-built sup*rt configurations and the design requirements were as noted be ow.
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| A. Support No. 481, Type Longitudinal A4 L Single angles were installed as braces in the longitudinal direction. A pair of angles is required by the design drawing.
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| : 2. The slopes of the upper longitudinal braces exceed the design limits. 1
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| : 3. The working point locations for the lower longitudinal bracn !
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| with respect to the beam elevation at the attachment to the hanger exceed the design limit.
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| : 4. The working points for all longitudinal braces, with respect to the anchor bolts, exceed the design limits.
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| : 5. The angle sections used for the longitudinal braces are inverted.
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| : 6. The length of several of the Hilti Super Kwik-bolts is insufficient to achieve the required minimum embedment.
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| 07/09/88 Revision 15 Page 122 CABLE TRAY SUPPOR'IS Review Issues List B. Support No. 408, Type B4 L 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 l
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| sections are to be used for the prescribed modification. A 6" channel section was actually installed. The configuration of l the notch, the weld pattern attaching the added members, the elevation of the top beam, and the Richmond Insert locations )
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| do not match the requirements of CMC 9916.
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| : 2. The bottom beam is a C4x5.4. A C4x7.25 is required.
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| C. Support No. 649, Type A1 This installation uses concrete anchorage "Alternate Detail 1" (Gibbs & Hill Design Drawing 2323-S-0903), which requires the use of an L6x6x3/4. An L5x5x3/4 was installed D. Support Nos. 722 and 2606, Detail "N", Drawing 2323 E1060101-S L The working point for the brace, with respect to the anchor bolts, exceecs the design limit.
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| : 2. For Support No. 2606, the length of the C6x82 beam is less than required
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| : 3. For Support No. 2606, the base angle is an L6x6x3/4, whereas the design requires an L5x5x3/4.
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| E. Support Nos. 2992, 2994, 3005, 3017, 3021, 6654, Type A2 Reference 1 identified the above six supports as follows "A2 (except all members shall be MC6x12), "where L = 8' 3" (frame width), h = 4'-2" (frame height),
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| L The Cygna walkdown documented the installed hanger member sizes, as listed below in Table L Due to the presence of i
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| 07/09/88 Revision 15 Page 123 CABLE TRAY SUPPORTS Review Issues List Thermolag conting, which covers the entire bottom beam member and part of the hanger members, Cygna was unable to determine the installed beam member size.
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| TABLE 1 Cable Tray Suooort Hanner Member Sizes Dimensions
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| * Member Sizes Flange Support Depth Width No. (In) (In) Existine*
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| 2992 6 17/8 C6 x 8.2 2994 6 1-7/8 C 6 x 8.2 3005 6 1-7/8 C 6 x 8.2 3017 6 17/8 C6 x 8.2 3021 6 17/8 C6 x 8.2 6654 6 2-1/8 C6 x 13 Dimensions of the vertical channels (hangers) are based on measurements by,Cygna. Member sizes are I determined by selectmg the channel type from l Reference 3 which most closely matches the measured l depth and flange width.
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| i
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| : 2. The beam for Support No. 2992 was accessible and was found to be a C4x7.25 instead of the required MC6x12.
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| : 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 dim:nsion was less than required.
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| : 4. For Support No. 2992, a separation violation was noted .
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| between a Richmond Insert on the east hanger and a Hilti !
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| Kwik-bolt on an adjacent pipe support.
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| 07/09/88 Revision 15 Page 124 CABLE TRAY SUPPORTS Review Issues List F. Support No. 455, Type SP-8
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| : 1. De brace connected to the wall on one side of the support is located cu: side of the bolt pattern on the base angle. The Detail "B" (2323-S-0903) type connection requires the brace l to be located between the two bolts.
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| : 2. The distance from the face of the concrete wall to the support is less than that required on the design drawing.
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| : 3. Gaps of up to 1/4" between the base angles and the concrete, without grout or shims, were noted.
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| : 4. The distance between the top 11/4" Hilti Super Kwik bolt on the north brace attachment and a 1/4" Hilti Kwik bolt attaching the Thermo Lag to the wall is less than the minimum spacing requirement.
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| G. Support Nos. 2998 and 13080, Special Type Supports These supports were installed on floor slabs with 2" topping.
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| Tb. topping depth was not considered in selecting the length of t'.ie atahor bolts, and the required minimum bolt embedment length was not achieved.
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| l H. Milti Super Kwik bolts Without Stars Sectl0n 3.1.3.1 of Brown & Root Procedure CEI 20 (Reference 11) requires:
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| Hilti Super Kwik bolts shall be additionally marked with a "star" on the end which will remain exposed upon installation.
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| Twenty-eijtht of the cable tray supports inspected by Cygna required t w installation of Hilti Super Kwik bolts. Of these, on.y two supports had stars stamped on the bolts. De bolts on the remaining supports were not stamped. Therefore, Cygna was unable to verify that the correct bolt type had been installed.
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| 07/09/88 Revision 15 Page 125 CABLE TRAY SUPPORD Review Issues List I. Contact Between the Component Cooling Water (CCW) Heat Exchanger and Cable Tray Support Nos. 332 and 408.
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| See Issue No. 20.K.
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| J. Support No. 2953, Detail "E" (Drawing 2323-E10601-01-S)
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| This support is attached near the end of an embedded strip plate.
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| The distance from the end of the embedded plate to a penetration through the concrete wall was less than the minimum distance required for the embedded Nelson studs used to anchor the embedded plate to the concrete.
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| K. Proximity Violations Between Cable Tray Supports and Other Components 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:
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| Suotort No. Violation Description 202 1/2" clearance between beam and insulation on pipe passing through support 299 Brace and hanger near top of support in contact with 'Ihermolag on conduits 332 0" clearance from CCW heat exchanger 408 1/2" clearance between hanger and pipe i
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| passing through support,0" clearance from CCW heat exchanger 605 1/8" clearance between end of beam and an HVAC duct TU Electric Comanche Peak Steam Electric Station k- ' A Independent Assessment Program - All Phases liliitilllilillfilillilllillil Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN
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| 07/09/88 Revision 15 Page 126 CABLE TRAY SUPPORTS Review Issues List 758 1/8" clearance between brace and pipe running parallel to support frame 765,766,767 1" clearance between braces and pipe passing through support 2986 Hangers are in contact with Thermo-lag on an 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
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| : e. pipe 3016 Bottom beam is in contact with insulation on <
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| a pipe !
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| 3022 5/8" clearance between bottom beam and ,
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| insulation on a pipe l 13131 Thermo-lag on the cable tray is in contact with the rear bracket of the strut for a pipe support L Support No. 758, Detail "V" (Drawing 2323-E1060101-S)
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| : 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.
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| : 2. An anchor bolt spacing violation existed between one Hilti Super Kwik-bolt on the south hanger and the anchorage for a rod hanger from a fire sprinkler line, l M. Support No.124, Type D2 L The channel sections installed were C6x10.5 and C4x5.4 for the bottom and top beams, respectively. The design requires C4x7.25 sections.
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| : 2. The Richmond Insert pattern for the beam anchorage does not match that shown on CMC 1078, Revision 0.
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| N. Support No. 202, Type A4 L ne channel sections installed were C4x5.4 for the beams.
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| The design requires use of C4x7.25 sections.
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| : 2. The anchor bolt length for the south hanger attachment is insufficient to achieve the required minimum embedment.
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| O. Support No. 479, Detail "C", Drawing 2323-El-050001-S
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| ; ne length of the overlap between the hanger and the base angle is less than required by the design.
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| P. Support No. 589, Type Al L This support has an angle section added as a stiffener to the east C6x8.2 hanger, per CMC 2646, Revision 5. The installed weld pattern attaching the angle does not match that shown on the CMC.
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| 1
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| : 2. Each hanger is attached to the concrete using a single Hilti l Super Kwik. bolt; however, the anchor bolts are not centered I on the hanger as required by the design.
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| O. Support No. 590, Type Al L This support has an angle section added as a stiffener to the east C6x8.2 hanger, per CMC 2646, Revision 5. De installed weld pattern attachm, g the angle does not match that shown i on the CMC.
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| : 2. The depth of the notch provided to clear the tray rail exceeds the 3/4 inch limit given on CMC 2646.
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| R. Support No. 605, Detail "A", Drawing 2323-El050004-S TU Electric Comanche Peak Steam Electric Station
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| Review Issues List The cable tray is attached to the this support using Type II friction clamps. The gage distances for the bolts attaching the clamps to the support beam are not within the design limit.
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| S. Support No. 638, Type SP-4 L The slope of the brace member exceeds the design limit of l L51 l
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| : 2. The brace is attached to the frame using a gusset plate, which is not allowed by the design. 1 I
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| : 3. The working point of the brace with respect to the base angle is not within the design tolerance.
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| T. Support No. 724, Detail "N", Drawing 2323-E10601-01-S l L The length of the C6x8.2 bearn was less than the required 6' 5r length.
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| l
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| : 2. The L3x3x3/8 brace was attached to the incorrect side of the !
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| gusset plate on the beam.
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| : 3. An L6x6x3/4 was used instead of the required L5x5x3/4 for the beam base angle.
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| : 4. The anchor bolt types and locations do not agree with the I requirements of CMC 155, Revision 0.
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| I U. Support No. 763, Detail "K", Drawing 2323-E10601-01-S i
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| The installed base plates are 11/4" thick. The design requires !
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| the use of 3/4" plates.
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| V. Support No. 764, Detail "K", Drawing 2323-E1060101-S L The installed base plates are 11/4" thick. The design requires the use of 3/4" plates.
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| : 2. The trey attachment uses heavy-duty clamps with 1/2" A307 bolts attaching the clamp to the tray. The distance from the i
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| 07/09/88 Revision 15 Page 129 CABLE TRAY SUPPORTS Review Issues List end of the clamp to the bolt on one clamp is less than required by the design.
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| : 3. The channel used as a spacer between one tray and the support beam is not the required MC3x9 shape.
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| W. Support Nos. 765, 766, 767, Detail "T, Drawing 2323.E1060101-S
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| : 1. The in-plane braces for these supports are attached directly to the supports' south base angles. The design requires that the brace be attached to the hanger member, below the base angle.
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| : 2. For Support No. 766, there is a spacing violation between one of the Richmond Imerts on the south hanger attachment and an adjacent Hilti Kwik bolt.
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| : 3. For Supx>rt No. 767, there is a spacing violation between one of tie Richmond Inserts on the south hanger attachment and the anchorage for a rod hanger.
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| X. Support No. 2602, Detail "W", Drawing 2323.E1060101-S Two non-seismic conduit supports were attached to this support at the east end of the W8x31 beam. The attachment of these conduits was not shown on any of the applicable CMCs affecting this support.
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| Y. Support No. 2986, Type A4 This support installation has one Hilti Super Kwik bolt for each hanger anchorage. The design drawing (232M0909) requires that the bolt centerlines coincide with the hanger centerlines, however the bolts are up to 1/4 inch off center.
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| Z. Support No. 3026, Type SP-4
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| 'Ihe north beam is a C4x5.4 section. The design requires the use of a C4x7.25 section. Since the other members were
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| , covered with Thermo. lag, their sizes could not be determined.
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| I)
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| = .- -
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| 07/09/88 Revision 15 Page 130 CABLE TRAY SUPPORTS Review Issues List AA. Support No. 3028, Type D1 L The east hanger is composed of two separate pieces of channel, a C6x8.2 and a C6x10.5, butt welded together approximately 11 inches above the ;able trays. This is not in accordance with the design requirements.
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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.
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| BB. Support No. 3134, Detail "11", Drawing 2323-S0905
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| : 1. The beam length is 6 inches greater than that shown on CMC 8585, Revision 3.
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| : 2. The longitudinal braces were L3x3x3/8 seccions. The design requires the use of L31/2x31/2x3/8 sections.
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| : 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.
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| CC. Support No. 5807, Type Longitudinal Al L The slope of the longitudinal braces are not with design tolerance.
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| : 2. The L3x3x3/8 sections for the braces are inverted.
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| : 3. The weld between the west brace and the hanger does not provide the required minimum weld length.
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| : 4. The welds between the guseet plates and the base angles are not per design requirements.
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| : 5. The working points of the longitudinal braces with respect to the anchor bolts are not within the design tolerance.
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| TU Electric Comanche Peak Steam Electric Station
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| ' LJ' ' Independent Assessment Program - All Phases IUU""U"'"U"""""" TUE\84056\RIL-2. MAN Job No. 84056 Revision 15
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| 07/09/88 Revision 15 Page 131 CABLE TRAY SUPPORTS Review Issues List
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| : 6. The location of the TS6x6 from the attached pipe support does not correspond with the location shown on CMC 80294, Revision 0.
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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 the required minimum embedment.
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| DD. Support No. 332, Detail "A", Drawing 2323 El 0700-01-S
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| : 1. The concrete edge distance for the Hilti expansion anchors exceeds the 10 inch limit required by DCA 4897, Revision 0,
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| : 2. Separation violations between the top anchor bolt and the anchor bolts for pipe support CC-2-01003-A33R are not documented.
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| EE. Support No. 629, Type SP-7 with brace
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| : 1. The slope of the longitudinal brace is not within the range allowed by the design.
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| : 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.
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| FF. Support No. 631, Type SP-7 )
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| i 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.
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| GG Support No. 720, Type SP-7 Separation violations between the bottom Hilti Super Kwik bolt and the anchor bolt on an adjacent support is not documented.
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| HH. Support No. 734, Detail "H", Drawing 2323-E1060101 S I
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| TU Electnc Comanche Peak Steam Electric Station '
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| l The top and bottom beams are not located within the design j location tolerance. !
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| II. Support No. 790, Type SP-7 This support is located on the surface of an opening in a i I
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| concrete wall. An embedded plate is located 8 inches from the edge of the opening. The separation between the expansion anchors for the support and the embedded plate does not meet
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| - the requirements of Gibbs & Hill Specification 2323-SS 30 (See i l
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| Issue No.17.F).
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| JJ. Support No. 2920, Type SP-7 with brace
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| : 1. This support uses a gusset plate to attach the longitudinal brace to a horizontal base angle. This connection is not !
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| allowed by the design drawing.
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| : 2. The location of the brace with respect to the anchor bolts does not meet the design requirements.
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| KK. Support No. 3016, Detail "F", Drawing 2323 El 060101-S 4 l
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| : 1. The bolt hole end distances on the base plate exceed the design limit of 3 inches.
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| : 2. The center anchor bolt is a 1 inch diameter expansion anchor. The design requires a minimum 11/4 mch diameter bolt.
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| 1 LL Support No. 3022, Detail "F", Drawing 2323 El 060101-S l
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| The locations of the Richmond Inserts do not agree with those shown on CMC 4534.
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| MM. Potential Root Causes of Construction Dis::repancies.
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| 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 TU Electric Comanche Peak Steam Electric Station
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| CABLE TRAY SUPPORTS Review Issues List propam. Specifically, Cygna raised the following questions dunng the meeting documented in Reference 16:
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| : 1. After the as-built drawing development is completed, will an effort be made to compare theec drawings with the original design drawings to identify a potential root cause of the construction defi:icncies?
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| : 2. Has an evaluation been performed to establish the root cause of the drawing quality problems?
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| : 3. What changes in project procedures have been made to prevent a reoccurrance of similar problems in futute work at CPSES7 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 20J and 20.L through 20.LL are addressed through the design verification of the as-built support configurations. j However, due to the state of the construction of CPSES, certain components on a number of supports are no longer accessible for inspection (i.e., hidden or inaccessible attributes) Reference 20 is the joint Impell/Ebasco approach towards design verification of inaccessible attributes. See Issue No.16.A.
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| Issue No. 20.K, proximity violations between supports and other components, has been addressed. Per Reference 19, TU Electric has ,
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| , developed sxcifications Q(eference 22) to address the separation /c.carance requirements between the cable tray systems and .
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| other compwents. This issue has been transferred to Reference 21, !
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| Civil / Structural Review, Issue No.10. Cygna notes that spacing violations will also be covered by SWEC (Reference 19) l 4
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| MM: Cygna understands that a 100% hardware / installation reverification is being performed and, as such, the generic implications of these discrepancies are no longer a concern with regard to cable trays.
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| i TU Electric Comanche Peak Steam Electric Station
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| CABLE TRAY SUPPORTS i Review Issues List Status: All issues regarding as-built discrepancies (A-J, I LL) are closed based on the current support as built program. Based on a review of the procedures for the development of as-built drawings (Reference 17),
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| Cygna raised several concerns. These are discussed in Issue No. 33.
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| Issue No. 20.K: See Reference 21, Civil / Structural Review Issue No.10.
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| Issue No. 20.Mht Closed.
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| ==References:==
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| L Gibbs & Hill Drawings 2323-El 060101 S, 2323-E10700-01 S, !
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| 2323-E10713 01-S
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| : 2. N.H. Williams (Cygna) letter to J.B. George (TUGCO), "Cable Tray Support Design Review Questions," 84056.022, dated August 17, ,
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| 1984, que: Sons 1, 2, and 6
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| : 3. N.H. Williams (Cygna) letter to J.B. George (TUGCO), "Cable Tray Support Design Review Questions," 84056.025, dated August 21, 1984, Question No.1 :
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| i
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| : 4. Gibbs & Hill Cable Tray Support Design Drawings 2323-S-0900 :
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| Series t
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| : 5. Gibbs & Hill Calculations for Support Numbers 3025, 3028, 2861, !
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| Cygna Technical File 84056.11.1.225 i
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| : 6. LM. Popplevcell (TUGCO) letter to N.H. Williams (Cygna), .
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| "Responses to Cygna Review Questions" dated Septemer 4, !
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| 1984, with attached calculations
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| : 7. GitN & Hill Calculation Binder 2323-SCS-101C, Set 3, Sheets 206, ,
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| Reveion 6
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| : 8. LM. Popplewell (TUGCO) letter to N.H. Williams (Cygna), l "Response to Cygna. Design Review Questions," dated September 11, 1984, with attached calculations
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| : 9. Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 5
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| : 10. Gibbs & Hill Drawing 2323-S.0901, Revision 4
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| : 11. N.H. Williams (Cygna) letter to J.B. George (TUGCO), "Cable Tray Support and Electrical Review Questions" 84056.019, dated August 10, 1984, Question Nos. 2.1 and 2.2
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| : 12. Gibbs & Hiil Drawings 2323-El-060101-S, 2323-E10700-01-S, and 2323.E10713-01-S TU Electric
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| _ _ - _ _ . _ . . _ . . - . . _ . ~ . _ . _ _ _ _ . _ _ . _ _ . . _ . . .,
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| 1 07/09/88 l Revision 15 1 Page 136
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| (
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| CABLE TRAY SUPPORTS Review Issues List
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| : 13. Gibbs & Hill Specifications 2323-ES-19, "Cable Tray ,
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| Specification," Revision 1
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| : 14. Gibbs & Hill Calculation Binder 2323-SCS.111C, Set 8
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| : 15. Communications Report between P. Huang (Gibbs & Hill) and J.
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| Russ (Cygna), dated June 13, 1984
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| : 16. LM. Popplewell (TUGCO) letter to N. Williams (Cygna), ,
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| "Comanche Peak Steam Electric Station Cygna Review Questions" dated August 27, 1984 with attachments i
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| : 17. R.E. Ballard (Gibbs & Hill) letter to J.B. George (TUGCO), Cable Tray Supports Cygna Phase 4 Audit Activities," GTN-69377, dated August 24, 1984, with attachments
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| : 18. L.M. Popplewell (TUGCO) letter to N. Williams (Cygna),
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| "Comanche Peak Steam Electric Station Cygna Review tauestions" dated September 11, 1984, with attachments
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| : 19. Gibbs & Hill Caleulations Binder 2323-SCS-111C, Set 7
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| : 20. TUGCO Instruction CP-EI-4.0-49, Revision 1 2L TUGCO, "Cable Tray Thermo-lag Evaluation, Safeguards Building, E'evation 790'6." Cygna Technical File 84056.1L1.1.315
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| : 22. N.H. Wi"iams (Cygna) letter to J.B. George (TUGCO), "Cable Tray Support Review Questions" 84056.041, dated February 12, 1985
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| : 23. Communications Report between M. Warner (TUGCO) and N. Williams et al (Cygna), lated February 27, 1985
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| : 24. N.H. Williams (Cygna) letter to V. Noonan (USNRC), "Response to i NRC Questions," 8.N.023, dated March 8,1985 1
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| : 25. Brown & Root Cable Trsy Har,ger Assembly Drawing FSE-00159
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| : 26. Gibbs & Hill Design Procedure DP 1, "Seismic Category I Electrical Cable Tray Supports," Revision 0, dated June 11, 1984 i
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| , TU Electric
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| ' g ', ' ' Comanche Peak Steam Electric Station i Independent Assessment Program - All Phases ll1111lll111111111111lll111111 Job No. 840'4 Revision 15 TUE\84056\RIL 2. MAN
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| - _ _ . . . _ . . . .1
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| 07/09/88 Revision 15 Page 137 CABLE TRAY SUPPORTS Review Issues iist
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| : 27. N.H. Williams (Cygna) letter to V!.G. Counsil (TUGCO), "Cable Tray / Conduit Support Review Questions," 84056.089, dated October 21,1985
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| : 28. N.H. Williams (Cygna) letter to J.B. George (TUGCO), "Cable Tray Support Review Questions" 84056.027, dated August 27, 1984
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| : 29. Ebasco Procedures SAG.CP4, "Seismic Design Critaria for Cable Tray Hangers for CPSES Unit 1", Revision 6 and SAG.CP3, "Seismic Design Criteria for Cable Tny Hangers for CPSES Unit 2", Revision 9
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| : 30. TU Electric Procedures TNE FVM CS001, "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 Hr.nger As-Builting and Design Adequacy Verification Progre:n",
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| Revision 1, October 18, 1986. Supplemental Procedure for Unit 2 Walkdown, TNE-FVM-CS019, "Selected Cable Tray Attributes Data Collection Unit 2", Revision 1, September 3,1986
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| : 31. Ebasco Instruction SAG.CP34, "General Instructions for Cable Tray Hanger Analysis for CPSES Nos.1 and 2", Revision 11
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| : 32. Impell Instruction PI42, "Dynamic Analysis of Cable Tray Systems", Revision 6
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| : 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
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| : 34. Impell Calculation M 39, ""Me Rail Extension Study", Revision 1
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| : 35. Transcripts of the Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna, Ebasco, Impell, JBA and SWEC held at the CPSES Site, May 19, 1987
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| : 36. Impell Report IM T-0210-040 233. "Impell/Ebasco Approach Towards Design Verification of Maccessible Attributes," dated May 15,1987 TU Electric Comanche Peak Steam Electric Station
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| 07/09/88 Revision 15 Page 138 CABLE TRAY SUPPORTS Review Issues List l
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| : 37. Communications Report between S. Harrison et al (TU Electric);
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| P. Harrison (Ebasco); G. Ashley (Impell); and J. Russ (Cygna), ;
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| dated September 3,1987,10:00 a.m.
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| : 38. Communications Report between S. Harrison (TU Electric); P. ,
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| Harrison (Eba m); G. Ashley et al (Impell); and J. Russ et al ;
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| (Cygna), deed November 17,1987, 300 p.m. ,
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| i
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| : 39. Communications Report between S. Harrison et al (TU Electric); ;
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| P. Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al ,
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| (Cygna), dated December 9,1987,1:30 p.m. .
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| Summary: A. Tracking and Consideration of Design Chenges f During the course of the design and construction of cable tray i supports, a large number of design change documents (DCAs and l CMCs) have been issued that affect the support designs. These design changes can be grouped into two categories. Generic l design changes are issued against a Gibbs & Hill support design !
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| diawing (e.g.,2323-S.0901) and may affect all installations of one ,
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| on more generic support designs. Individual design changes are I issued against a support layout plan (e.g.,2323.E1060101-S) and affect one or more individual support installations. .
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| , Cygna's review has identified several areas where oversights or !
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| errors may occur in the handling of these design changes. j These may be due in part to the large numbers of design changes ;
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| which have not been incorporated in the design drawings. l
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| : 1. Generic Evaluations l
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| In the process of performing generic evaluations of support :
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| design adequacy (e.g., the inclusion of base plate flexibility 1 in response to IE Bulletin 7902, the Working Point Deviation Study, the evaluation of the effects of weld undercut / underrun, etc.), G.bbs & Hill based their calculations on the original support designs without considering the effects of all applicable generic design changes (Reference 27).
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| : 2. Case-by-Case Design Adequacy Reviews j In some cases, as a result of the generic studies discussed above, the dengn limits for a support type were made more !
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| restrictive tl4.1 those of the original design. In order to ,
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| qualify existig supx>rts which had been specified based on the onginal design imits, a case by<::ase design adequacy review was performed for all individual supports which exceeded the revised design limits. These reviews were based on the as-designed configurations for the individual supports, and did not include the effects of applicable individual design changes (Reference 27).
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| : 3. Tracking of Design Changes Affecting Individual Supports The design changes for individual supports are tracked by the cable tray support plan drawing number rather than by the support number. In order to locate all design changes affecting a given support, one must manually search through all design changes affecting all supports on the applicable support plan. Cygna observed that some support plans have over 200 design changes outstanding. In order to exp.dite this effort, the TUGCO Field Structural Engineering Group (FSEG) maintains a list of design changes sorted by individual support number. This list is not a controlled document, and Cygna's review noted several discrepancies between the design changes listed for indivi'lual 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 engineer to determine which design changes should be considered in their evaluations of field change requests.
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| : 4. Design Changes Used For Q.C. Inspections A discussion with TUGCO cable tray support installation Q.C.
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| 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. TUGCO Q.C.
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| 07/09/88 Fevision 15 Page 140 CABLE TRAY SUPPORE Review Issues List indicated that the inspectors typically relied on the list of design changes included in the Brown & Root construction package as a basis for inspection witF out independently verifymg the completeness of the pe xage.
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| : 5. Adequacy of Design Review Cygna has noted instances where the design review for the verification of design changes may have been inadequate.
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| The design changes allowed deviations from the original design that invahdated certain 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 not assess the impact of the change on all components of a support that would be affected. r mples of this include:
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| 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 calculation of the resisting moment arm when a bending moment is applied to the base angle. CMC 1970 reduced this distance to a minimum of 1-1/4". The design review for this CMC did not consider the impact of this reduction on the anchor bolt designs.
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| o Cable tray supports are designed for a frame width based on a mimmum distance of 3" from the outside tray rail to the inside of the flar.ge of the hanger (See Issue No.
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| 28.A) CMC 2645 allows the hanger to be notched so 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 design.
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| The design review for this CMC only addressed the reduced section propcrties at the notch without considering the effect on the support width.
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| 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 TU Electric Comanche Peak Steam Electric Station
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| 07/09/88 Revision 15 Page 141 CABLE TRAY SUPPORTS Review Innes List trays and the clamps attadhing 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).
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| o Cable trays are qualified for an 8'-0" maximum span ,
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| (See Issue No. 25.B) DCA 1594 provides an installation l location tolerance for the. supports, resulting in a 1 maximum spacing of 9'# beti een supports. The design t review for this CMC does not consider the effect of the I increased span on the cable tray qualification.
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| B. Criteria Violations in Individual Support Specifications on Support Plans In the generic design of cable tray supports, support dimension and loading limitations are determined for each support type.
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| These limitations are typically stated in the design calculations, but are not shown on the generic support design drawings I (Reference 4). The riimensions for each support are specified in I a descriptive block on the support plans (Reference 1), and the I loading is indicited by the supported tray width shown.
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| The tray supports listed below were identified as having loadings or support geometries which exceeded the design limitations.
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| Prior to the Cygna review, justifying documentation did not exist for the following individual support designs.
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| : 1. Support Nos. 3025, 3028,2861, Type D1 Drawing 2323-E1071301-S specifies these supports as Type D 1(except beam to be MC6x163), L = II'#, h = 4'-2", and shows a tray width of 78". The design calculations for Type D1supports limit L s 8'-0" and the tray width to 48".
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| : 2. Support No. 2W7, Type A1 TU Electric Comanche Peak Steam Berm 6e exam Independent Assessment Pragtsun - AT Pbses killimlililliIIIllilililliJob No. 84856 Revision 15 TUE44056\RIL-2. MAN
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| 07/09/88 Revision 15 i Page 142 l CABLE TRAY SUPPORTS Review Issues List Drawing 2323-E1060101 S specifies dimensions of L = 2'-9" and h = 4'6" for this support. The design calculation for this support type limit h $ 2'-4".
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| : 3. Support No. 657, Type Al l
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| Drawing 2323-E10601-01 specifies this support as Type A1, L = 7'-0", h = 2'-0". The design calculation for this support type limit L $ 6'-0".
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| : 4. Support No. 734, Detail "H", Drawing 2323-E10601-01-S This drawing specifies that one beam is to be an MC6x151, rotated 900 from its normal orientation. The support design requires the use of C6x8.2 beam sections. The etion i modulus of MC6x15J about its weak axis,1.75 i , is smaller than that of C6x8.2 about its strong axis,4.38 in .
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| Therefore, this support should be reevaluated for vertical loads. Rotating the MC6x15.1900 from its normal orientation <
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| significantly increases the longitudinal stiffness of the I support. This rotation, together with CMC 00164, which ,
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| requires the use of a "heavy duty clamp," can introduce I significant longitudinal loads to the support. The support design requires the add: tion of a longitudinal brace if longitudinal loads are to be resisted.
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| I
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| : 5. Support No. 3011, Type SP-6 Drawing 2323-E10713 01-S specifies dimensions of L = 8'-9" and h = 4'6". The design calculation for this support type ;
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| limits L $ 6'-0".
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| : 6. Support Nos. 2992, 2994, 3005, 3017, 3021, 3111, 6654, Type A2 Drawing 2323-El-0713-01-S specifies dimensions of L = 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".
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| CABLE TRAY SUPPORTS Review Irsues List i
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| l 1
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| : 7. Support Nos. 95 and 112, Type SP-7 Drawing 2323.E1070041-S specifies these supports as Type SP-7, L = 5'-1", and shows a tray width of 48". The design calculations for Type SP-7 limits the tray width to 30".
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| : 8. Support No. 758, Detail "V", Drawing 2323-El-0601 S Drawing 2323-El-0601-01-S specifies this support as Detail "V", b l= 8'-4", h 2 = 7'-3", h3" 4' 0" 1 1= 5'-9", Ig= 2'-3", a =
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| 2'4", and shows a tray width of 66". The design for the support detail limits the tray width to 60".
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| : 9. Support Nos. 765, 766 and 767, Detail "J", Drawing i 2323-E10601-01-S Drawing 2323 E1060101-S specifies these supports as Detail "J", L = 8' 6", h = 1 10'-10", hg= 9'-6", h 3= 3'-6", and shows a tray width of 66". The design for the support detail limits the tray width to 48".
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| 1 Additionally, Gibbs & Hill was not consistent in establishing controlling criteria (i.e, support dimensions, tray width, etc.) in l 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 Cygna's scope, support types E4, SP 6 and SP 8 are affected.
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| C. Consideration of As-Built Support Conditions in Generic Reviews Which Require a Case-by-Case Review
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| : 1. The SP-7 weld underrun analysis considered 5/16" fillet welds which are specified on the design drawings. However, the FSE.00159 fabrication drawinp 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 Issue No. 21.A)
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| i CABLE TRAY SUPPORTS Review Issues List 1
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| I
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| : 2. The Working Point Deviation Study did not include the effects of all applicable design changes (See Issue No.12). ;
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| D. Inconsistencies in the Evaluation of Cable Tray Supports For Thermo. lag Application L Tray cover weights were not included in the development of the allowable span length tables (References 19 and 20) for fire-protected cable trays.
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| : 2. Cygna believes that longitudinal supports are not evaluated for the added weight of fire protection. C,,gna noted evidence of the above in the fire protection reviews for cable tray segment T120SBD07. A longitudinal support (type I A )1 was assumed to provide transverse restraint in the fire protection calculation. The calculated transverse load was compared to an assumed des'gn capacity, but no longitudinal load was calculated. The original design for this support l type assumes that only longitudinal restraint is provided.
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| Note that the calculations (Reference 21) reviewed by Cygna i had not been design reviewed at the time they were received !
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| from TUGCO. I l
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| : 3. Gibbs & Hill performed calculations to determine the design capacit; for supports for 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.
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| : 4. For several cable tray segments within Cygna's review scope, the tray weight, includm, g fire protection, exceeded the design limit of 35 psf by up to 6%, but engineering evaluations were not performed as required by Reference 20.
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| See Reference 27, Question No. 3, for a listing of the affected tray segments.
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| : 5. For tray segment no. T130SCA46, side rail extensions were installed, but a special evaluation was not provided as required by Reference 20 (See Issue No. 25.C.1),
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| Revision 15 !
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| Page 145 l l,
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| CABLE TRAY SUPPORTS !
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| Review Issues List !
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| l Cygna has requested additional information on the fire !
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| protection evaluation process in Reference 27. l l
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| E. Tray Spans Between Supports Used In the Original Support Layout L Reference 13 indicates that cable trays are to be designed and qualified for 8'-0" transverse and vertical spans.
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| Reference 10, Note 13, allows a location tolerance for supports of 1/2 of the Richmond Insert spacing parallel to ;
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| the tray, and limits the maximum spacing between supports to ;
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| 9'-0." Gibbs & Hill cable tray support design calculations assume a maximum tributary span of 8'-6," to account for a ,
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| support spacing of 8'-0" on center and an erection tolerance ;
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| of 6." l l
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| Cygna reviewed the tray support plans for segments withm i' the review scope (Reference 12) and noted 15 locations where the as<iesigned tray spans exceeded 8'-0". Cygna's walkdown i of these tray segments identified 5 locations where the !
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| as-built tray spans exceeded 9'0" (See Reference 11). This i indicates that the design and installation limitations for !
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| support spacings may not have been complied with in the !
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| preparation of support layout drawings and in the field. ;
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| : 2. Reference 13 indicates that cable trays are to be designed and qualified for 40'-0" longitudinal spans. Longitudinal i support design calculations assume a maximum ongitudinal :
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| tributary span of 40'-0". For several supports withm Cygna's review, the support plan drawings (Reference 12) showe<.
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| longitudinal supports hasing tributary spans greater than 40'-0" (See Reference 11). In addition, several horizontal tray segments were not provided with any longitudinal supports (See Reference 11). This indicates that the design limitations for the location of longitudinal supports may not have been complied within the preparation of support layout drawings.
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| 07/09/88 Revision 15 Page 146 CABLE TRAY SUPPORTS Review Issues List ;
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| F. Lack of Calculations For Change Notices Cygna has noted several design reviews of change notices where the Change Verification Checklist (CVC) was marked to indicate '
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| that new or revised calculations were not required. Cygna considers some of the design changes to be significant, such that calculations should have been provided to justify their acceptability. In some cases, calculations marked "for reference only" are attached to the CMC which the reviewer had accepted without new or revised calculations.
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| G. Design Calculation Retrievability and Completeness
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| {
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| During the course of the Phase 2 and 4 reviews, Cygna experienced difficulty in assembling complete supwrt design [
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| calculation sets. Cygna noted that Gibbs & Hill us similar l difficulty. The following exampic.s illustrate Cygna's concerns. l t
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| L In Phase 2 of Cygna's IAP, Cygna requested an evaluation of !
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| the effect of torsion in the C4x7.25 beams on the support design adequacy. Gibbs & Hill provided calculations .
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| (Reference 14, Sheets 28-33) which evaluate torsion in the !
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| beams. These calculations were performed in 1982, but were -
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| 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.
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| : 2. Cygna requested a list of all calculations relevant to several generic support designs (Reference 15), Gibbs & Hill ;
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| provided a list of calculation binder and sheet numbers for ,
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| each support type. The review of these calculations by Cygna indicated that there were additional calculations relevant to the support designs which had not been included on the list. For example, the Working Point Deviation Study involved several supports listed in Reference 15, but was not referenced in Gibbs & Hill's response.
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| l 07/09/88 l Revision 15 Page 147 CABLE TRAY SUPPORTS Review Issues List The difficolties in identifying and locating all calculations pertinent to a support design may be in part attributable to Gibbs & Hill's mthods of controlling structural design calculations. Cygna observed that, as a general rule, Gibbs &
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| Hill did not revise or supersede older calculations. In performing generic studies (e.g., Working Point Deviation Study, weld undersize / 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 superseded by the new calculations, nor are they revised to reflect the results of the design changc or gener,ic study. Hence, l it is extremely difficult, from reviewmg an origmal design 4 calculation, to determine if it is still applicable to the support design. It is also difficult to identify and locate generic study or design change review calculations that are applicable to the support design.
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| H. Lack of Controlled Design Criteria At the initiation of this review, the cable tray support 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 msufficient 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 desigr. criteria include:
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| L Cygna has noted instances where the field design review group did not utilize the proper criteria to evaluate support adequacy. He 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.
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| Since the maximum tributary span assumed in the current design calculation is 8'-6", the use of a 9'-0" span overestimates the allowable load.
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| : 2. Cygna has asked what supplements to the 7th Edition of AISC Specifications were committed to in the FSAR. No TU Electric Comanche Peak Steam Electric Station
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| 07/09/88 Revision 15 Page 148 CABLE TRAY SUPPORTS Review Issues List evidence was found to indicate that proper direction was given to design engineers to utilize the requirements of any supplements to which CPSES was committed.
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| I. Differences Between Design Drawings and Assembly Drawings Cygna performed a review of the cable tray support assembly drawings (Reference 25), which are used for 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:
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| o Incorrect weld sizes specified for fillet welds. (See Issue No.
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| 16.A) o Incorrut weld patterns o Incorrect member sizes specified in the "Bill of Material" o Incorrect anchor bolt connection details o Incorrect support dimensions o Members that are not required by the design For a detailed listing of the individual discrepancies, see Reference 24.
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| Response: A. The design verification of cable tray supports is based on the as built support configuration, as specified in 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 inaccesible attributes.
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| Design verification for supports with inaccessible attributes is discussed in Reference 36.
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| B. This is no longer an issue since all of the supports are now individually design verified.
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| Revision 15 l Page 149 CABLE TRAY SUPPORTS Review Issues List C. This is no longer an issue since the results of the Gibbs' & Hill generic studies are no longer used.
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| D. All cable tray supports will be individually evaluated, considering the weight of Thermo-lag, if applicable.
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| : 1. Per Section III of Reference 29, Ebasco considers 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 the covers.
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| : 2. The design verification of cable tray supports include all support types (transverse, longitudinal and multi-directional).
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| Thermo-lag weights are included as applicable.
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| : 3. The original Gibbs & Hill calculations for cable tray supports considering Thermo-lag are no longer used.
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| : 4. The cable tray system evaluation is based on the as-built tray and cable weights. However, References 29 and 32 indicate that if the as-built weight of the tray is unavailable, a normal weight of 35 psf should be used. This raiws several questions-
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| : a. In what cases are the as-built cable fill weights unavailable? Are there any outstanding issues relative to the accuracy or completeness of the cable and raceway schedule?
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| : b. Since Cygna has found instances where the actual tray weight exceeded 35 psf, what is the justification for using 35 psf?
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| In Reference 35, the response to these questions was given as follows-In Unit 1 the Ebasco and Impell design verification is based on as-built data, and the 2323 El1700 Report 30 to determine the cable tray analysis weights and fills. TU Electric will use the CARDS 1
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| module of the INDMS program for the long term I maintenance of cable tray weights.
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| The program inputs are as follows:
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| o The weight of tray, siderails and side covers.
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| o Cable tray hanger number to corresponding cable tray nodes.
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| o The analysis weights used in the Impell and Ebasco i calculations.
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| The program outputs will be:
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| o Actual cable tray weights and reports that give cases where actual tray weights exceed analys!* (ray weights.
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| TU Electric will only accept cable tray hanger calculations after the design and actual tray weights are reconciled.
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| Procedures to address the future cable additions-TU Electric has developed procedures to address the future cable fill additions. The procedures have to be used in conjunction with the CARDS module which requires that the CARDS module be run prior to any changes in the raceway cable filt The propam will flag any raceway in which the assumed design fill is exceeded. The raceway fill will also be checked prior to the turnover of any Ebasco and Impell cakulations to assure the accuracy of the weights used for the design verification. Cygna has reviewed and accepted these procedures. (Reference 39)
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| : 5. Ebasco includes the weight of the cable tray siterail extension in calculating the tray weight (Reference 29).
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| the impact of siderail extension (s in the cable tray syste evaluations is not significant. Cygna requested that the weight of the extensions be considered.
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| 07/09/88 Revision 15 Page 151 CABLE TRAY SUPPORTS Review Imues List Subsequent to the above discusion, Impell has agreed to reconcde all the actual cable tray weights, including the side rail extension weights. See also Issue No. 2LD.4.b.
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| 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 discussion of the evaluation of the acceptability of the cable trays, see Issue No. 25. See also Issue No. 33.C for a discussion on cable tray span walkdowns.
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| F. Since 100% of the cable tray supports are being design verified, calculations associated with the review of previously issued design changes are no longer used. TU Electric has developed procedures to control the review of any design changes that may be generated in the future. Cygna's review of this area is contained in the Design Cntrol Review Issues List.
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| G. The original Gibbs & Hill and TUGCO design calculations are superceded by the current cable tray support design verification effort.
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| H. Both Ebasco and Impell have developed sets of design criteria, project instructions and proccUres to assurs, consistency and :
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| compliance with the CPSES FSAR for all calculations associated !
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| with the cable tray support design verification program. I I. The cable tray support design verification program is based or.
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| the as built support drawings. No reliance is placed on the original Brown & Root assembly drawings.
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| Status: A. Closed.
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| B. Closed.
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| C. Closed.
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| D. L Closed.
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| : 2. Closed.
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| TU Electric
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| : 3. Closed
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| : 4. Closed.
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| : 5. Closed 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 the cable tray span walkdowns.
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| l F. Closed G. Closed H. Closed Cygna's review of the design criteria and work instructions used for the cable tray, support design verifications has noted differences in the analysis methods and assumptions used by the two consultants. Such differences are noted and reconciled in the applicable lccations within the Review Issues List.
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| Cygna has reviewed and accepted the criteria and analysis methods used individually by each consultant to assure consistency with the approach taken within their individual work scope.
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| I. Closed TU Electric Comanche Peak Steam Electric Station
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| : 22. Design of Suocort No. 3136. Detail "5". Drawing 2323.S-0905
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| ==References:==
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| L Gibbs & Hill Calculation Binder SAB-1341, Set 3, Revision 0
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| : 2. Communication Report between B.K. Bhujang (Gibbs & Hill) and N. Williams et al (Cygna), dated October 20, 1984
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| : 3. Gibbs & Hill Calculation Binder SAB1341, Set 3, Revision 1
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| : 4. N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO), "Cable Tray / Conduit Support Review Questions", 84056.089, dated i October 21, 1985 j
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| : 5. Transcripts of the Cable Tray Hanger Design Verification i
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| Meeting between TU Electric, Cygna, Ebasco and Impell at the CPSES Site, January 26 and 27,1987
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| : 6. Transcripts of the Cable Tray Hanger Design Verification Meeting l between TU Electric, Cygna, Ebasco, Impell, JBA and SWEC held I at the CPSES Site, April 21,1987
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| : 7. Cygna Energy Services, "Civil / Structural Review Issues List,"
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| Revision 0, dated July 21, 1987
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| : 8. Communications Report between S. Harrison (TU Electric); ,
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| P. Harrison et al (Ebasco); arf. J. Russ et al (Cygna), dated May l 1,1987, 2:30 p.m.
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| 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 l noted several concerns. A list of Cygna's questions was provided (Reference 2, Attachment A) to Gibbs & Hill for their review. These concerns included:
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| o Justification for not considering tornado depressurization loads was not provided.
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| o Tiie mginal cable tray support is Seismic Category I, while the fire wall is Seismic Category II.
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| TU Electric Comanche Peak Steam Electric Station f
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| 1 07/09/88 Revision 15 Page 154 CABLE TRAY SUPPORTS Review Issues List Justification for this conflict in design classification was not provided.
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| o Several errors were found in the finite element model and in the calculations.
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| Response: During the discussions in Reference 6, Ebasco provide the following response: Isolated cases of cable tray hangers supported from Category II structure are identified and evaluated on a case-by-case basis.
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| Seismic Category II walls affected by Category I attachments will be qualified by the SWEC Civil Structural Corrective Action Program.
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| Status: This issue is closed here, and is transferred to Reference 7, Civil / Structural Review Issue No. 9.
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| : 23. Loadine in STRESS Models
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| ==References:==
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| L Gibbs & Hill Computer Output Binder 2323-DMI-5P
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| : 2. Gibbs & Hill Calculation Binder 2323-SCS-215C, Set 2
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| : 3. Gibbs & Hill Drawing 2323-S-0001, Revision 4
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| : 4. Cygna Energy Services, Report No. TR-83090, "Independent Assessment Program Final Report - Volume 1, for Texas Utilities Services Inc., Comanche Peak Steam Electric Station," Revision 0
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| : 5. Ebasco Instruction SAG.CP34, "General Instructions for Cable Tray Hanger Analysis for Comanche Peak SES No.1 and 2",
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| Revision 11
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| : 6. Transcripts of the Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna, Ebasco, Impell, JBA and SWEC held at the CPSES Site, May 19, 1987
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| : 7. Communications Report between P. Harrison et al (Ebasco) and J.
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| Russ et al (Cygna), dated May 1,1987,11:20 a.m.
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| : 8. Communications Report between H. Schoppmann (Ebasco) and W.
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| Horstman (Cygna), dated September 22,1987,1000 a.m.
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| : 9. Communications Report between H. Schoppmann et al (Ebasco) and W. Horstman (Cygna), dated September 23,1987,11:50 a.m.
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| l Summary: For the design of standard support Cases Ai , Bi , Ci and D i, where i = 1 to 4, finite element analyses were performed (Reference 1) using the computer program STRESS. Single beam elements were used to model the horizontal members )
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| inaccurate due to the following(beams) con: erns: The analytical results may bl A. Tray Load Application Point Tray loads were applied at the beam / hanger intersection, rather I than within the span of the beam where the tray is physically located. Modeling the load placements in this fashion eliminates the effects of bending and torsion due to vertical loads on the TU Electric Comanche Peak Steam Electric Station
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| i t
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| beams, and for Cases Dj, will totally remove the load applied at the wall connection from the support.
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| Observation CI'0003 in Reference 4.) (See Cygna's Phase 2 1 1
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| B. Tributary Load Calculations The applied loads are calculated based on an 8'-0" tributary tray span. The actual design span is 8'-6" if installation tolerances are considered.
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| C. Modeling 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 l the top of the C4x7.25 beam. The models considered this !
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| distance to be from the concrete to the centerline of the beam, thus underestimating the support height by two inches. This error is also found in the related design calculations for the trapeze supports. )
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| Response: Under the cable tray support design validation effort all supports are ,
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| individually evaluated. The results of the Gibbs & Hill calculations are !
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| no longer used. 1 I
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| A. For response spectrum analyses of cable tray supports, both l
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| Impell and Ebasco generate cable tray system models which have the tray loads applied to the support at the tray centerline l location. This is an acceptable approach.
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| 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 locations. However, the horizontal transverse load from 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 Reference 7, Ebasco provided a study which addresses the effects of the modeling assumption.
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| l TU Electric l Comanche Peak Steam Electric Station
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| ' bJL A Independent Assessment Program - All Phases ilillinililllilllililllilliti Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN 1
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| 07/09/88 Revision 15 Page 157 CABLE TRAY SUPPORTS Review Issues List This study was in the form of preliminary calculations (Reference 8) and addresses Cygna's concern pertaining to the "Generic" as well as the "Individual Support" evaluations (Reference 9).
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| : 1. Generic Evaluations The cable tray support modeling technique was evaluated by comparing the axial stress in tier reported in the results of a detailed NASTRAN analysis with those from STRUDL analysis performed in accordance with the project modeling criteria.
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| Since the application point for transverse loads only affected the axial load in the tier, this comparison could be :
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| used to quantify the impact of the modeling technique used.
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| For the representative trapeze type hanger, the axial streu in the tier contributed less than 5% to the total member stress interaction ratio. Since the axial stress did not i govern the design of the tiers, such an effect on interaction :
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| ratio was insignificant. 1
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| : 2. Individual Support Evaluations Since the modeling technique used in RSM models correctly predicted the tier axial stress, individual supports from RSM models were chosen. A sample of eight RSM models out of 43 RSM models were selected, giving a total of 95 hangers for review. These included transverse, longitudinal and the multi-direction supports. The sample selection was based on engineering judgment rather than the random sampling. For the 95 supports, the axial stress interaction ratio, fa/Fa, was tabulated. The maximum interaction value was noted to be as 0.043. This agreed with the value of 5% noted in the generic evaluation.
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| Based on the above results, Ebasco concluded that the magnitude ,
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| of the axial stresses in tiers was insignificant with respect to the '
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| total stress interaction ratio, and hence need not be considered ;
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| (Reference 9),
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| TU Electric Comanche Peak Steam Electric Station
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| ' J' A Independent Assessment Program - All Phases ll111llllllll11111111111lll111 Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN e, - , ,, , , , , - , , . , - ,- . . , . , . , ~ - - - - , . - - , , - . - - . - , c- - . - . , . , ,,--,--r,,,-
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| CABLE TRAY SUPPOR'IS Review Issues List l
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| l R The curwnt cable tray support design verification effort does not use the results of Gibbs & Hill's support analyses. Therefore, this is no longer an issue.
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| C. See response for Issue No. 23.R Status: A. Closed. However, the 5% increase in stress interaction ratio needs to be considered in the cumulative effects evaluation (Issue No. 29).
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| R Closed.
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| C. Closed.
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| h P E ectd
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| ,g ogram 1 Phases umimillilitilllitilllilli Job No N UEWOS6\ Rib 2. MAN
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| : 24. Desien of Flexural Members
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| ==References:==
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| 1 N.H. Williams (Cygna) letter to J.B. George (TUGCO), "Cable Tray Support Review Qi-dama*' 84056.031, dated August 31, 1984
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| : 2. LM. Popplewell (TUGOO) letter to N.H. Williams (Cygna)
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| "Comanche Peak Steam Electric Station Cygna Review Q= tim" dated September 28,.1984
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| : 3. Communication Report between E. Bezkor et al (Gibbs & Hill) and M. Fngleman et al (Cygna), dated April 11, 1985
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| : 4. Gibbs & Hill Drawing 2323-S4903
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| : 5. Ebasco Instruction SAG. CP34, "General Instructions for Cable Tray Hanger Analysis for CPSES Nos.1 and 2," Revision 11
| |
| : 6. Ebasco Calculation, "Comanche Peak SES Cable Tray Hanger Volume 1," Book 2, "Computer Related Information", Revision 3
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| : 7. Ebasco Calculation, "Comanche' Peak SES Cable Tray Hanger Volume 1," Book 7,"Cable Tsay Hanger 1.oad Application Location Study," Revision 1
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| : 8. Ebasco Procedures SAG.CP4,Tw:ismic Design Criteria for Cable Tray Hangers for CPSES Unit 1," Revision 6 and SAG.CP3, "Seismic Design Criteria for Cable Tray Hangers for CPSES Unit 2," Revision 9
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| : 9. Impell Instruction PI02,"Dynamic Analysis of Cable Tray Systems," Revision 6
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| : 10. Impell Calculation M-12,' Qualification Procedures for Cable Tray Support Evaluations," Revision 6
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| : 11. Impell Instruction PI11, "Cable Tray System Analysis and Qualification Closeout" Revision 3
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| : 12. Impell Instruction PI.03,"Qualification af Cable Tray Supports," Revision 3 TU Electrr.:
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| Comanche Peak Steam Electric Station
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| : 13. Ebasco Procedure SAG.CP11, "System Analysis for Cable Tray and Hanger Assembly for CPSES Units 1 & 2", Revision 4
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| : 14. Transcripts of the Cable Tray Hanger Design Verification Meeting i between TU Electric, Cygna, Ebasco and Impell held at the CPSES Site, January 26 and 27,1987
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| : 15. Communication Report between R. Ramsey et al (Impell); S. l Harrison (TU Electric); R. Alexandru et al (Ebasco); and J. Russ, i et al (Cygna), dated February 2,1987
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| : 16. Nuclear Construction Issues Group, NCIG-01, "Visual Weld Acceptance Criteria', Revision 2
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| : 17. Ebasco Response EB-T-3029, Attachment 3, "Effective Section at Anchorage for Composite Members" dated May 15, 1987 ;
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| i
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| : 18. Ebasco Response EB-T-3029, Attachment 4, "Enhancement of COMBS Computer Program Verification Manual," dated May 15,1987
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| : 19. Impell Report IM P-005, "Evaluation of Composite T-channel Stitch Welds for Toisional Stresses," Revision 1, dated May 15, 1987
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| : 20. Ebasco Response EB-T-3029, Attachment 2, "Major Axis Bending Due to Transverse Loading," dated May 15, 1987
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| : 21. Communications Report between P. Harrison et al (Ebasco) and W. Horstman et al (Cygna), dated June 25,1987,11:40 a.m.
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| : 22. Ebasco Calculation No. 3306.514, Dept. No. 558, Revision 0
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| : 23. Communications Report between P. Harrison et al (Ebasco) and W.
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| Horstman et al (Cygna) dated June 23,1987,1000 a.m.
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| : 24. Communications Report between G. Ashley (Impell) and W.
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| Horstman et al (Cygna), dated Mcy 151987,12:30 p.m.
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| : 25. Communications Report between G. Ashley (Impell); S. Harrison (TU Electric); and W. Horstman et al (Cygna), dated May 14, 1987
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| : 26. Impell Calculation M 59, ' Tee Channel Stitch Welds and Web l Crippling" Revision 3 j l
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| : 27. Communications Report between P. Harrison (Ebasco); S. Harrison l (TU Electric); and W. Horstman et al (Cygna), dated April 29, i 1987,10.15 a.m. and 2 p.m. I
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| : 28. Communications Report between SJ. Chen, J. Christoudias, P.
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| Harrison, J. Swanson (Ebasco); and W. Horstman, J. Russ (Cygna), l dated April 30,1987, 9.00 p.m. j
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| : 29. Communications Report between S. Harrison (TU Electric); G.
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| Ashley, R. Kaczkowski (Impell)', D. Williams (QEST); and John Russ (Cygna), dated July 10,1967,1000 a.m.
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| : 30. Communications Report between P. Harrison (Ebasco) and W.
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| Horstman (Cygna), June 23,1987,600 p.m. l 3L Communications Report between S. Harrison (TU Electric); P.
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| Harrison et al (Ebasco); and W. Horstman et al (Cygna), dated May 1,1987, 2:30 p.m.
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| : 32. Communications Report between S. Harrison (TU Electric); P.
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| Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated November 17,1987, 300 p.m.
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| : 33. Communications Report between S. Harrison (TU Electric); P.
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| Harrison (Ebasco); G. Ashley (Impell); and J. Russ et al (Cygna),
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| dated December 1,1987,11:10 a.m.
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| M. Ebasco Response EB.T-3395, Figure No.1-C-2, "Response to Cygna's Generic Questions Concerning Composite Cnannels Attached to Base Angles" dated August 20, 1987 ;
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| : 35. Impell Report IM P.015, "Effect of Eccentric Bolt Holes on Weak Axis Bending of Tier Members" Revision 0, dated October 20, 1987 TU Electric Comanche Peak Steam Electric Station
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| : 36. Communications Report between P. Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated December 10, 1987, LOO pm I
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| : 37. Communications Report between S. Harrison et al (TU Electric); l P. Harrison et al (Ebasco); R. Kaczkowski et al (Impell); and J. l Rus et al (Cygna), dated January 21,19s3,2:30 p.m. i l
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| : 18. Communications Report between S. Harrison et al (TU Electric);
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| P. Harrison er, al (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna); dated January 27,1988,1000 a.m. i
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| : 39. Communications Report between J. Christudios et al (Ebasco) and l B. Shakibnia (Cygna), dated February 5,1988,11.00 am. ;
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| : 40. Communications Report between S. Harrison (TU Electric);
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| P. Harrison (Ebasco); R. Kazcowski (Impell); and W. Horstman i (Cygna), dated Febuary 24,1988, 9:00 a.m.
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| : 41. Communications Re. port between P. Harrison (Ebasco) and W. ,
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| Horstman (Cygna), dated February 26,1988,12:30 pm Summary: In the design of cable tray support flexural members (i.e., beams and i hangers, now generally referred to as tiers and posts, respectively),
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| Gibbs & Hill did not censider several important items as discussed i below.
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| A. Mejor Axis Bending Due to Transverse Loading Additional major axis bending stresses due to transverse loads are introduced by the vertical eccentricity between the cable tray centerlines and the beam neutral axis (Reference 1) Gibbs & l Hill provided calculations (Reference 2) indiceting that the I incree*, 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 loed transfer mechanism that was assumed to be provided by the tray clamps may not be applicable to all clamp configurations.
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| B. Minor Axis Bending Due to Transverse Loading Minor axis bending of the beams due to transverse loading is ,
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| introduced by the honzontal eccentricity between the beam !
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| clamp bolt holes in the :
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| neutral beam's top axis flange and(Reference the locatioc of the tray & Hill's response 1). Gibbs ;
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| i (Reference 2) did not consider the allowed tolerance in bolt hole gage per DCA 17838, Revision S. A load transfer mechanism was !
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| assumed to be provided by the clamp, allowing the trays and I supports to act as a system. This assumption results in increased !
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| transverse loads on adjacent supports and no minor axis flexure !
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| in the beams. i l
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| C. Torsion Due to Vertical Loadmg ,
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| 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 response (Reference 2),
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| the torsional moment was completely eliminated, based on an assumed moment resistance provided by the tray clamps and the tray / support system concept (See I2 sue No.10 for an evaluation !
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| of the system concept) ]
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| D. Torsion Due to longitudinal Loading Torsion is introduced into the beam by longitudinal loading can be categorized into two types-
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| : 1. The vertical offset between the tray centerline and the beam shear center (for longitudinal trapeze type supports, e.g, L-A1, L B1).
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| : 2. The vertical offset between the tray centerline and the shear center of the composite beam (for longitudinal supports similar to SP-7 with brace, Detail 8, drawing 2323-S0)03, t- )
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| Grobs & Hill's evaluation of the torsional effects are included in Reference 2. The evaluation of torsion due to Icadhg type 1 only considers the eccentricity between the shear center and the top of the tray rungs for ladder type trays or the tray bottom TU Electric Comanche Peak Steam Electric Station l
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| CABLE TRAY SUPPORTS Review Issues Lir.t I for trough type trays. The centroid of the tray fill is a more appropriate location from which to calculate the eccentricity.
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| For loading type 2, the longitudinal load is epplied at the bottom of the tray side rails, rather than the centroid of the tray fill. -
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| De tray clamps are assumed to provide rotational restraint to ,
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| the top flange of the composite beam, and all torsional moments are assumed to be resisted by a couple formed between adjacent vertical supports through flexure of the cable tray. All these assumptions must be justified per Issue Nos.10 and 18.
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| E. Reduction in Section Properties Due to Bolt Holes and Weld Undercut Gibbs & Hill has not consistently considered the reduction in the i beam section properties due to bolt holes through the fianges j (see Issue No. 9) and weld undercut effects. Based on CMC 58338, Revision 0, the welded connection between the beam and hanger can include vertical fillet welds crossing the web of the i beam, thus weld undercut would affect the beam capacity at this !
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| critical location. Weld undercut could also affect the beam i capacity at beam-to-base angle / plate connection for the i cantilever type of supports. In addition, based on the tray installation tolerances provided in Gibbs & Hill Specification 2323-ES100, Section 2.28, and the effect of CMC 2646, Revision 5, the tray clamp can be located such that the bolt hole is in the same cross-sectional plane as the effect of weld undercut.
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| Thus, it is possible that both reductions may occur simultaneously.
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| F. Evaluation of Shear Stresses Gibbs & Hill has not evaluated the effects of shear stresses on beam acceptability. Shear stresse will be introduced by two loadings-
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| : 1. Direct shear stresses due to the applied forces
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| : 2. St. Venant shear stresses associated with torsional loads l (See Items C and D above),
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| 07/09/88 Revision 15 Page 165 CABLE TRAY SUPPORTS Review Issues List Cygna's review indicates that direct shear stresses are 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 member design (Reference 3).
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| G. Unbraced Length for I.ateral Torsional Buckling Gibbs & Hill generally assumes an allowable major axis bending stress of 22 ksi for member designs. The capr.ity reduction based on the unsupported length of the beam's compression flange (AISC Equation 1.57) is either not considered at all or not :
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| 3roperly considered (See Issue No.14). Justification is provided, msed on the assumption that the tray and tray clamp will provide lateral bracing to the beam's compression flange. This assumption is dependent on the tray clamp's ability to provide bracing (see Issue No.18) and neglects compression of the bottom flange due to support frame sidesway and seismic uplift. ,
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| For cantilever type supports, the T value in Ecuntion LS 7 is improperly selected as discussed in Issue No.14.B.
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| H. Increase Factor for Warping Normal Stresses l See discussion in Response Section below.
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| Response: A. For system models, Impell, per Reference 9, Section 3.2.4, and Ebasco, per Reference 13, include an eccentricity equal to the distance from the tray center of gravity to the beam center of gravity.
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| The effect of the vertical eccentricity is considered in the analysis of the cable tray nupports. For equivalent static analyses, Elssco, per Reference 5, Attachments B1 and B2, ;
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| applies a major axis bending moment to the suppent which is l equal to the applied transverse load times the distance from the beam center of gravity to the bottom of the tray. Ta!s approach is based on Study No. 7b (Reference 6) In Refotoce 15, Ebasco indicated that the load was assumed to act at the tray bottom rather than at the tray center of gravity. Cygna did not agree with this assumption and requested additional justification.
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| TU Electric
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| [H . Comanche Peak Steam Electric Station IIttiliitttttilililliitittilli Independent Assessment Program - All Phases Job No. 84056 Revision 15 TUE\84056\RIL 2. MAN i
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| 07/09/88 Revision 15 Page 166 CABLE TRAY SUPPORTS Review Issues List Ebasco's response was based on a comparion of tier stress j interaction ratios from models which differed solely as to the point of transverse load application for three sample supports.
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| One model applied the moment based on 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 centerof gravity (Reference 20). The increase m, overall stresses was less than 3% and Ebasco concluded that this increase was negligible. Cygna reviewed Reference 22 and questioned if the three selected supports represented the supports j with the highest interaction ratios for tiers. Ebasco stated the 4 chosen samples were representative supports. but not necessarily those with the highest interaction ratios. I i
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| Cygna also asked how Attaciunent Z (Reference 5) connectivity was considered in Reference 22. Ebasco stated the calculation was performed prior to inclusion of Attachment Z loeds and that ,
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| all calculations would be revised to account for the effect of connectivity. Ebasco felt that the inclusion of connectivity will not increase the 3% difference in combined stresses, but may actually decrease it.
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| Since the increase in overall stresses was less than 3%, which may decrease due to the consideration of Attachment Z loads, Cygna accepted Ebasco's study. This issue will be considered in Cumulative Effects review in Issue No. 29.
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| B. The minor axis bending moment due to this eccentricity is I considered explicitly by Ebasco, Attachments B1 and B2 of :
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| Reference 5, in individual support models used for equivalent l static analyses. The eccentricity used is equal to the distance between the beam center of gravity and the clamp bolt location.
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| For system models, Ebasco, per Reference 13, includes a horizontal eccentricity (equal to the distance between the beam ;
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| i shear center and the web centerline) to account for torsion due the eccentricity is approx (imately equal to or greater than theto distance between the clamp bolt bole centerline and the minor neutral axis (Reference 15) i l
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| TU Electnc :
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| Comanche Peak Steam Electric Station Nb 'A Independent Assessment Program - All Phases liillilit!Illillililllllilitil Job No. 84056 Revision 15 TUE\84056\RII 2. MAN l
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| CABLE TRAY SUPPORTS Review Issues List Impell, in Reference 10, indicates that the effect of this eccentricity is not significant and will riot be considered In Reference 10, a moment egual to the 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 betwan 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 was not adquately justified.
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| During discussion between Impell and Cygna, it was demonstrated that the tier may experience significant acditional stress if minor axis bending was considered (Referenca 24). If the tier is highly stressed due to other loadings, then the additional stress due to minor axis bending may result in interaction ratios greater than unity.
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| Subsequent to the above discussion, Impell provided a report 1 addressing this topic (Reference 35) for Cygna review. This report summarized a study (Cakulation M 12, Appendix G)ier evaluating 60 sample supports. Minor axis bending in the t member was considered, resulting from an eccentricity equal to the distance between the beam center of gravity and the clamp bolt location. The calculations indicated that such additional minor axis bending increased the interaction ratio by an average !
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| of 0.01 and that the maximum increase was only 0.02. None of l the members in sample study were found to be overstressed.
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| Based on the above results, Cygna concluded that the current Impell practice of neglecting the minor axis bending of the tier due to the eccentricity was acceptable. (Reference 38.)
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| 1 C. For equivalent static analyses, Reference 5, Attachments B1 and i B2, and for system models, Reference 13, Ebasco considers an eccentricity equal to the distance between the shear center of the tier and 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 tansferred at the locatio1 of the web centerline.
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| This loading point is re' wnable for downwards loading from the l
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| l TU Electric Comanche Peak Steam Electric Station ALJa A
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| Independent Assessment Program - All PMses lilitiilillimillitililllilli Job No. 84056 Revision 15 TUE\84056\RIL 2. MAN I
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| ,, , , - . - - - . - , . ,,.,....,-,,,n , - . , , . , , . , , , , , , , , , . ,.,__.n_,_,
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| 07/09/88 Revision 15 Page 168 CABLE TRAY SUPPORTS Review Issues List tray, but may be unconservative for upwerds loading, which would I be applied at the clamp bolt location.
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| Based on additional discussions, it was concluded that the additional torsion due to upwards seismic loading was not l significant. Since dead weight counteracts upwards seismic, the l net upward accelerations are low. In addition, since the warping j normal stresses sre considered to be directly additive to bending i normal stresses, the torsional evaluation is already very )
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| conservative.
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| Impell, per Reference 9, Section 3.2.4, includes an eccentricity equal to the distance between the tier's shear center and center of gravity. This is included in the model by providing a spring capable of resisting only vertical tray loads at the end of a rigid link with a length equal to the eccentricity. However, Impell 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.
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| As discussed in Issue No.18, Impell provided an evaluation which demonstrated that releasing the rotational spring (Mz) did not i have a significant effect on the torsion in the tier.
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| {
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| 1 D. For system models, Ebasco in Reference 44, and Impell in Reference 9, Section 3.2.4, model an eccentricity equal to the l
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| distance between the center of gravities of the cable tray and '
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| l the tier. This practice is acceptable.
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| For ec uivalent static models, Ebasco, in Reference 5, Attachments B1 anc. 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 eccentricity used is the distance between the l centerline 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 modeling practice is used based on the assumption that a portion of the torsion will be resisted as minor axis bending of the cable tray since the two bolts are capable of developng a force couple.
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| TU Electric MJ' Comanche Peak Steam Electric Station A
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| 111111111111l16Ill111111111111 Independent Assessment Program - All Phases Job No. 84056 Revision 15 TUE\84056\RIL 2. MAN
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| 07/09/88 .
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| Revision 15 Page 169 CABLE TRAY SUPPORTS Review Issues List Cygna requested an evaluation of the impact of this bending moment on the cable trays. ,
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| In response, Ebasco revised the 1700 tray qualification calculations within their scope to check the impact of this additional moment on the tray stress interaction ratio. These i calculations indicated that the tray interaction ratio increased by l less than 0.02 when the moment m the tray due to the I longitudinal load was included. In the original tray evaluations only three trays were found to be overstressed out of the total population. Such failures were at mid: pan and not at the support locations. No additional failures were found when this moment was included.
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| Ebasco concluded that inclusion of the moment due to the longitudinal load had an insignificant effect on the cable tray !
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| qualification (Reference 36). I E. The evaluation of the effect of bolt holes through the channel f flange is addressed in Issue No. 9. i Since the supports will be individually evaluated based on the as-built support configuration, weld undercut does not have to be ;
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| considered on a geactic basis. The Project is performing weld l inspections in accordance with Reference 16. If the welds satisfy i the undercut limitations given in Reference 16, undercut will not !
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| be considered in the analyses. If the undercut exceeds the ,
| |
| allowable, the inspection report for the support is marked !
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| , unsatisfactory and the weld undercut will be repaired. )
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| 1 The Visual Weld Acceptance Criteria (P.eference 16) has been !
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| accepted by the NRC and is documented in SSER 12. Cygna has ,
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| reviewed this document and accepted it. l i
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| F. De evaluation of cable tray suport members locludes consideration of the effects of cirect shear and St. Venant shear stresses. This is specified in Section VI and Attachment M of Reference 5 and Attachments 4 and 5 of Reference 12. In l addition to the shear stresses associated with torsional loads, the ;
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| warping normal stresses due to torsion are included in the j member evaluations. :
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| i l
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| TU Electric g Comanche Peak Steam Electric Station hyggg[ggjn[ginjn; Independent Assessment Program - All Phases Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN !
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| f
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| 07/09/88 Revision 15 Page 170 CABLE TRAY SUPPORTS Review Issues List Impel! and Ebasco consider the entire cross-section of composite tee-channels to be effective in resisting torsional moments.
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| Cygna has expressed concern that this assumption is not correct as the anchorage connections of such members may not allow participation of the full composite cross-section. Ebasco provided an evaluation to address this issue in Reference 17.
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| Ebasco, in Reference 17, concluded that the composite channel section, when welded along one member only to the base angle, will participate in resisting torsion and that the weld was critical when compared to the shear in the composite section.
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| Cygna questioned the degree of participation of the connection in resisting torsion evaluation did no(i.e., semi-fixed or fully fixed) Also thet clearly over the shear stress in the member (Reference 23). Ebasco provided a revision to this evaluation which addressed Cygna's concerns. Ebasco's response was accepted as justification for Impell's evaluations also.
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| For the stress analysis of composite tee-channels subjected to torsional and flexural loads, Ebasco uses an in house computer program COMBS. Cygna reviewed the User's Manual and Verification Report for COMBS and identified several areas of Concern:
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| : 1. Cygna noted that the verification report considered only one set of member boundary conditions and requested that the program verification be enhanced to include all the boundary condition options. Ebasco revised the verification, Reference 18, to include all the boundary condition options in the verification.
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| . 2. Cygna asked Ebasco how composite cable tray support members with multiple bracing or connection points were evaluated using COMBS. Ebasco provided Cygna with several sample calculations which demonstrated their use of the COMBS program for this purpose (Reference 27).
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| TU Electric Comanche Peak Steam Electric Station L LJL A Independent Aeaemment Program - All Phases llll1111ll111tlllllll111111lll Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN
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| 07/09/88 Revision 15 Page 171 l
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| CABLE TRAY SUPPORTS Review Issues List I
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| Cygna evaluated these sample calculations and concluded that Ebasco's methodology was conservative and hence acceptable (Reference 37).
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| G. See Response for Issue No.14.B.
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| H. As discussed under Issue Nos. 24.C, 24.D, and 24.F, torsion induced stresses are considered in the support design validation ,
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| effort. These stresses include shear and warping normal stresses. j In the member stress evaluations, the warping normal stress is 1 conservatively added directly to the axial and bending stresses.
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| This is performed automatically by Impell's A15C code check computer program, SUPERPOST. However, Ebare uses P-delta STRUDL, which does not consider the warping normal stresses when performing a response spectrum analysis. As an f approximation for the contribution of warping normal stresses to j the total normal stress interaction ratio, Ebasco developed a l factor,130, to be applied to the results from STRUDL Cygna reviewed the development of this factor, noted that it may not i always be conservative and that it was not specified in the project work instructions, Reference 31. :
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| Subsequent to Cygna's review of this topic, Ebasco elected to eliminate the use of the factor, and now requires that support members be evaluated directly for the actual warping normal stress level, via a hand calculation to supplement the results of the STRUDL stress check.
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| Status: A. Closed. However, this must be considered under the Cumulative Effects review, Issue No. 29.
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| B. Closed. However, this must be considered under the Cumulative Effects review, Issue No. 29.
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| C. Clased. However, Cygna is considering the differences in eccentric vertical load application as part of the Cumulative Effects review, Issue No. 29.
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| D. Closed.
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| TU Electric eg Comanche Peak Steam Electric Station Independent Assessment Program - All Phav.,s IIlllilillililliIIIlilli$111 Job No. 84056 Revision 15 TUE\84056\RIL 2. MAN l
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| i l
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| CABLE TRAY SUPPORTS Review Issues List E. For the status of the evaluation of bolt holes in members, see 1 Issue No. 9. !
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| l F. Closed G. See Issue No.14.B for status. ;
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| 1 l H. Closed )
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| I I
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| I l
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| i I
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| 1 i
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| 1 TU Electric Comanche Peak Steam Electric Station
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| 07/09/88 Revision 15 Page 173 CABLE TRAY SUPPORTS Review Issues List
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| : 25. Cable Trav Ounlification
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| ==References:==
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| : 1. Gibbs & Hill Specification 2323 ES-19, Revision 1
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| : 2. Gibbs & Hill Calculation Binder 2323-SCS111C, Set 7, Revision 1
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| : 3. TJ. Cope, Test Report and Calculations for the Qualification of Cable Trays
| |
| : 4. CPSES FSAR, Section 3.10B3, Amendment 44
| |
| : 5. Gibbs & Hill Specification 2323 ES-100, Revision 2
| |
| : 6. IEEE, "Recommended Practices for Seismic Qualification of Class 1E Equipment for Nuclear Power Generating Stations,"
| |
| Standard 344-1975
| |
| : 7. CPSES FSAR Section 3.7B3.5
| |
| : 8. Gibbs & Hill Drawing 2323 4-0901, Revision 4
| |
| : 9. 1 M. Popplewell (TUGCO) letter to N.H. Williams (Cygna),
| |
| "Response to Cygna Review Question 2.1 of Letter 84056.019," dated August 27, 1984 with attached calculations
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| : 10. TUGCO Calculation, "Cable Tray Thermo. lag Evaluation Safeguards Building, Elevation 790'.6," Cygna Technical File 8405611.1.1.315
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| : 11. TUGCO Instruction CP EI-4.0-45, Revision 1
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| : 12. l Tray / Conduit S(upport Review Questions"N.H. 84056.089, dated Williams Cygna)
| |
| October 21, 1985 l
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| : 13. Ebasco Calculation, "Comanche Peak SES Cable Tray Hanger l Volume 1", Book 1, "General Input Data", Revision 3 1
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| : 14. Impell Instruction PI.02, "Dynamic Analysis of Cable Tray Systems", Revision 6 i
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| l TU Electric i Comanche Peak Steam Electric Statx>n ObJ' .
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| ' Independent Amessment Program - All Phases i
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| 11111111llllltllllll11111ll111 Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN l
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| 07/09/88 Revision 15 Page 174
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| (
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| CABLE TRAY SUPPORTS I Review Issues List l
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| : 15. Impell Instruction PI.06, "Tray and Clip Qualification", Revision 2 1
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| : 16. CCL Test Plan No. 1903.201, "Static Tests of Cable Trays and Fittings", Revision 1
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| : 17. Ebasco Instruction SAG.CP34, "General Instructions for Cable l Tray Hanger Analysis for CPSES, Nos.1 and 2", Revision 11 J
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| : 18. Transcripts of the Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna, Ebasco and Impell held at the l CPSES Site, January 26 and 27,1987 l
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| : 19. Impell Calculation M-03, "Cable Tray Properties", Revision 4 l l
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| : 20. Communications Report between P. Harrison et al (Ebasco) and J. l Russ et al (Cygna), dated May 1,1987,1120 a.m. !
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| 2L Communications Report between P. Harrison (Ebasco) W. Horstman I et al (Cygna), dated, June 23,1987, 4.00 p.m.
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| : 22. Communications Report between P. Harrison et al (Ebasco); S.
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| Harrison (TU Electric); and B. Shalibnia et al (Cygna), dated, July 14,1987,10d0 a.m.
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| : 23. Communications Report between S. Chen (Ebasco) and D. Leong (Cygna), dated November 19,1987, 300 p.m.
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| : 24. Communications Report between S. Harrison (TU Electric); P.
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| Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna) dated November 20,1987,1:15 p.m.
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| : 25. Communications Harrison Ebasco); and Report J. Russbetween G. dated et al (Cygna Ashley),et December al (Impell);
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| 10, P.
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| 1987,1.00 (p.m.
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| : 26. Communications Report between S. Harrison et al (TU Electric),
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| P. Harrison et al (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated January 25,1988,1:50 p.m.
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| TU Electric Comanche Pear Steam Electric Station
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| ' J' A Independent A-ment Program - All Phases tillimililllillilitilllillil Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN
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| 07/09/88 Revision 15 Page 175 CABLE TRAY SUPPORTS Review Issues List
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| : 27. Communications Report between S. Harrison et al (TU Electric);
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| P. Harrison et al (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated January 27,1988,10:00 a.m.
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| : 28. Communications Report between P. Harrison (Ebasco) and J. Russ (Cygna), dated March 30,1988,1:10 p.m.
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| : 29. Communications Report between P. Harrison (Ebasco) and W.
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| Horstman (Cygna), dated March 31,1988, 8:30 a.m.
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| : 30. Impell Calculation M 34, "Bending Capacity of the Cable Trays from Test Results and Axial Capacity from AISI Code Equations",
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| Revision 4 3L Impell Calculation M 54, "Interaction Equation and Factor of Safety for Cable Tray Qualification", Revision 0 l I
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| : 32. Impell Calculation M 35,"Capacities for Cable Tray Elbows Based on Test Results for Three Elbow Sizes", Revision 1 ,
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| : 33. Impell Calculation M-36,"Capacities for Cable Tray Tee and Cross Fittings Based on Analysis", Revision 0
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| : 34. Impell Calculation M 52, ' Torsional Moment Capacities for Cable Trays", Revision 1
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| : 35. Impell Calculation M 53, "Capacities of Cable Tray Reducers",
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| Revision 1
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| : 36. Ebasco Instruction SAG.CP18, "Procedure for Qualification of Cable Trays for Comanche Peak SES Units 1 and 2," Revision 3
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| : 37. Ebasco Calculation, "Comanche Peak SES Cable Tray Hanger Volume 1," Book 15, "Cable Tray Dynamic Load Redistribution Effects" Revision 4
| |
| : 38. Ebasco instruction SAG.CP28, "Procedure for Screening of Cable Tray Hangers to Assess the A plicability of a 1.25 MRM in Equivalent Static Method Ana ysis in Hanger Design Verification for Comanche Peak SES Units 1 and 2," Revision 3 TU Electric Comanche Peak Steam Electric Station
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| 07/09/88 Revision 15 Page 176 CABLE TRAY SUPPORTS Review Issues List
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| : 39. Impell Cakulation M 66, ' Transverse Behavior of Trays" Revision 2 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 noted several areas of concern.
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| A. Dynamic Amplification Factor Qualification of cable trays is performed through static load testing and calculation of loading interactions for dead load plus three components of seismic load (Rr':rence 1, Section 3.9 and Reference 3) Seismic loads are calcuated by the equivalent static load method, using total tray dead weight times the peak spectral acceleration. No apparent dynamic amplification factor (DAF) is used. Reference 6, Section 53, and Reference 7, recommend the use of a DAF = 1.5 unless justification is provided (See Issue No. 8).
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| B. Cable Tray Stress Interaction The interaction equation specified for checking cable tray capacity (Reference 1, Section 3.9.4) is limited in its apphcation and may have been used incorrectly.
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| The testing and qualification of cable trays is based on a 8'E simply supported tray span (References 1 and 3); yet Reference 8, Note 13, allows a support installation tolerance resulting in a l maximum tray span of 9'-0" for Unit 1.
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| The capacity values derived in the tray testing are total loads (lbs) uniformly distributed over an 8'0" section of cable tray (Reference 3) These values, Fn, Ft, and F1, as used with toe interaction equation, are only applicable to tray sections with 8'0" spans. However, for the fire protection evaluation calculations eference 2) and tray span violation calculations (Reference total loads for various tray spans were calculated as f' = (w)x(), where w is the tray unit weight and 1 is the tray l l
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| 1 i i 1 !
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| TU Electric ;
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| Comanche Peak Steam Electric Station i
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| 07/09/88 Revision 15 Page 177 CABLE TRAY SUPPORTS Review Issues List ,
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| I span. This load was compared with the rated tray capacity using the interaction equation.
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| l For evaluation of trays ;,ith spans other than 8'.0", a capacity comparison must bc inade p terms of tray bending moment which !
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| is proportional to (w) x (1), rather than the total oad on the i I
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| 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) wou d 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.
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| C. Modifications to Cable Tray Hardware and Siderail Extensions 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 walkdown indicates that this tray is actually a 24"x4" ladder-type tray with 6" siderail extensions added to increase the tray depth. The tray c.ualification test report does not provide qua:ification for trays using (Reference siderail extens3) ions. 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. built configuration of the tray system with actual cable weight shall be taken into account and proxr engineering evaluation performed. No stancard methodology is recommended, but shall be based on acceptable engineering practice.
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| The referenced calculations do not perform an evaluation of this tray segment. These cakulations (Reference 10) were obtained from TUGCO prior to their design review; TU Electric Comanche Peak Steam Electric Station
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| CABLE TRAY SUPPORE Review Issues List therefore, this possible omission may be corrected through the design review process.
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| : 2. Tray Segment T120SBC35 is joined to a tray reducer with siderail splice connector plates. These plates have been ;
| |
| modified by removing portions of their bottom flanges such that only the web area remains. This connector will not satisfy the requirements of Reference 1, Section 3.7, Paragraph f, which states that connectors "shall have moment and shear strengths at least equal to those of the continuous uncut siderail" Cygna was unable to locate documentation I
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| justifying this modification of vendor supplied hardware.
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| D. Cable Tray Section Properties Cable tray section properties are calculated using the static test results (Reference 3) The moment of inertia is cakulated 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 the deflection will be due to both flexure and shear deforme.tions.
| |
| This will affect the cakulated moment of inertia as used in any Gibbs & Hill analyses which consider the tray properties for .
| |
| frequency or displacement cakulations. i l
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| Response: A. Cable tray qualification is performed by Ebasco in accordance with Reference 36 and by Impell in accordance with Reference
| |
| : 15. When evaluating cable trays included in response spectra analyses, (i.e. all cabe trays in Impell's scope and all trays analyzed by the RSM in Ebasco's mope), the cable tray forces ,
| |
| and moments are taken directly from the analysis results. 1 For cable trays evaluated by the equivalent static method, (iz, Ebasco's ESM), a multimodel response multi > lier (MRM) is used.
| |
| The MRM value is dependent upon the cabe tray system spans, configuration ami support stiffnesses, but a minimum value of i I
| |
| 1.25 is used. The MRM is developed in Reference 37 and guidance for its application is provided in References 36 and 38.
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| A discussion of these cakulations and instructions are provided l
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| TU Electric i Comanche Peak Steam Electric Station ,
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| ' b ' ' Independent Assessment Program All Phases i 164i1611llll166611111111111lll Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN
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| I 1
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| l 07/09/88 l Revision 15 i Page 179 1
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| l CABLE TRAY SUPPORTS Review Issues List in Reference 23. All questions raised by Cygna have beer. l resolved. !
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| B. Cable trays are evaluated based on the individual as-built span lengths, cable fill weight and tray routing. These evaluations are performed in accordance with SAG.CP18 (Reference 36) and PI06 l (Reference 15) by Ebasco and Impell, respectively. These i instructions require that the cable trays and fittings be evaluated !
| |
| using an interaction equation which considers axial force, l torsion and two bending moments. This process replaces the I interaction equation based on axial force and total distributed l loading on the tray which was used by Gibbs & Hill, Inc.
| |
| For ESM anal is, the seismic force and moment ratios were .
| |
| combined by t e SRSS method to account for the spatial combination of earthquake components. For RSM analyses, a l linear interaction was used since the SRSS combination was performed within the response spectrum analysis (STRUDL or SUPERPIPE)
| |
| The capacities are based on a combination of original vendor test data, tray and fitting tests performed by CCL for CPSES, and l analyses, j o Ebasco developed the capacities for elbow and tee fittings from test results.
| |
| o Impell developed tee capacities analytically, so capacities used )
| |
| are different. Impell's analytical results were later verified against the test results to demonstrate conservatism. !
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| 1 o ne capacities for cross and wye fittings were developed analytically using extrapolation from the tee capacities.
| |
| l o Impell and Ebasco have made an effort to assure consistency in their development of the methods used for the cable tray and fitting evaluations. l o Impell Project Instruction PI.06 only provided the capacities for TJ. Cope trays. This is the only tray type used m the TU Electric Comanche Peak Steam Electric Station db a A Independent Assessment Program - All Phases lilllillillullillilillilillli Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN
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| 07/09/88 Revision 15 Page 180 CABLE TRAY SUPPORTS Review Issues List CPSES Unit 1 Reactor Building and Safeguards Building, which is Impell's work scope.
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| o Ebasco criteria SAG.CP18 provided capacities for both Burndy/ Husky and TJ. Cope cable trays. As a first attempt in tray qualifications, or if the actual manufacturer was unknown, the lower bound capacities for both types were used to evaluate the cable tray.
| |
| When using either test results or analysis, a factor of safety against the ultimate capacity is used. The factors of safety for cable trays were based on the AISI code.
| |
| o A factor of safety of 1.6 was used for the cable trays and fit 6ngs and 1.875 for the connections (splice plates).
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| o The same factor of safety was used for both OBE and SSE 1% dings. Therefore, only the SSE ana'ysis results were checked in cabic tray qualification. ,
| |
| i Studies performed by Impell indicated that the shear failure did i not govern the cable tray capacity for spans less than twelve feet. Therefore, shear interaction was only checked for the ;
| |
| spans greater than 12 feet, which are very rare at CPSES.
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| Ebasco procedure SAG.CP18 includes several 2ppendices which l provided detriled methods for the evaluation of specific cable I tray routings (e.g., stuJght runs, bends, offsets, crosses, etc.).
| |
| Ebasco indicated that these sections were needed for ESM analyses since ESM did not give forces and moments in t's cable trays. For RSM analyses, the procedure used was similar u Impell's procedure in PI.06.
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| C. For the desi verification Ebasco, in Attachment C of 1 Reference 1 includes the weight of siderail extersions in I calculafeg the dead weight of the tray but does not comider i their me'.ribution to tray stiffness. Impell does not consider the i mass e ciffness contributions of the siderail extensions since they ahume that the allowance for future cable routini accounts for the weight. However, at the co:npletion of the er .e tray '
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| design validation effort, TU Electric indicated that the ctual TU Electric Comanche Peak Steam Electric Station .
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| A NJa A Indepenent Amnt Prograrn All Phases l Jc' No. 84056 Revision 15 1111111111.1111llll111111111ll TUE\84056\RIL 2. MAN l
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| ._ l
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| 07/09/88 Revision 15 Page 181 CABLE TRAY SUPPORTS Review Issues List j tray weights will be verified against the value used in the evaluations. See Issue No. 21.D for a more detailed discussion. ,
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| In Reference 18, TU Electric indicated that modified splice plates l I
| |
| have been identified as a potential problem. TU Electric issued a Sipiificant Deficiency Analysis Report (SDAR 86 52) to address J this problem.
| |
| In order to resolve SDAR 86 52, a program was initiated to !
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| identify and disposition all mo$fied splice plates at CPSES.
| |
| Under the guidance of TU Electric Procedure TE FVM.CS048, l walkdowns were wrformed to identify the locations and types of !
| |
| splice plates insta. led. Raaad on the results of these walkdowns, in combination with analytical results, several worst case modified splice plate types were identified. A series of tests for modified splice plates were performed by CCL to determine their reduced capacities in minor axis bending. CapacMes for other loading i directions were developed in Appendix A of Reference 30.
| |
| The procedures used for the cable tray qualificatio.1, References 15 and 36, also require an evaluation of the :,p%e plates. As an initial cut, the lowest capacity splice plate ejg is assumed to 1;c located at the highest moment region. If it is not possible to achieve qualification with this assumpion, the actual type and i locatico of installed splice plate is d,termined. If the splice l plate still fails, replacement is performed. i D. Cable tray section properties r:e calculated based on test data (References 13,19 and 21) assuming loed-deflection behavior predominated by flexure. Impell provided a study, Reference 39, which demonstrates that the tested deflection response of the cable trays rhen compr. red with deflections calculated in accordance whh fleymal theory are in close agreement. The inclusion of shear deformation in the behavior is not significant.
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| Status: A. Closed.
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| B. Closed.
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| C. See Issue No. 2LD for the status with respect to the consideration of siderail extension weights.
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| 1 i TU Electric Comanche Peak Steam Electric Station A N'L 1 Independent Anne = ament Program - All Phases 111111llll11111111111ll11111ll Job No. 84056 Revision 15 TUE\84056\RII 2. MAN
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| 07/09/88 Revision 15 Page 182 CABLE TRAY SUPPORTS Review Issues List Closed for the effect of modified splice plates on cable tray qualification.
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| D. Closed.
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| TU Electric Comanche Peak Steam Electric Statx.>n t *hL iA Independent Assessment Program - All Phaser Job No. 840% Reymon b 111111111111111111111111111111 TUE\840%\RIL-2. MAN
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| 07/09/88 Revision 15 Page 183 CABLE TRAY SUPPOKIE Review T auen List
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| : 26. Race Angle Desion
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| ==References:==
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| : 1. Gibbs & Hill Cakulation Binder 2323.SCS 215C, Sets 2 through 6
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| : 2. Gibbs & Hill Calculation Binder 232MCS-101C, Set 1
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| : 3. Transcripts of the Cable TrayIksign Verification Meeting between TU Electric, Cygna, Ebasco and Impell held at the CPSES Site, January 26 and 27,1987.
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| : 4. Ebasco Instruction SAG.CP34, "General Instructions for Cable Tray Hanger Analysis for CPSES Nos.1 and 2", Revision 11
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| : 5. Impell Instruction PI.07, "Design Verification of Base Plates, Base Angles and Embedded Plates", Revision 4 i
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| : 6. Communications Report between G. Ashley et al (Impell); S. I Harrison (TU Electric); and W. Horstman et al (Cygna), dated May 14,1987,1045 a.m.
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| : 7. Impell Calculation M-15,"Base Angle Interaction Diagram Development," Revision 6
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| : 8. Communications Report between G. Ashley (Impell); S. Harrison (TU Electric); and W. Horstman et al (Cygna), dated May 14, 1987, 2:30 p.m.
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| : 9. Communications Report between S. Harrison (TU Electric); P.
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| Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated October 12,1987, 930 a.m.
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| Summary: A. Base Angles Modeled as Simply Supported Beams l In References 1 and 2, the base angles were modeled as simply !
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| supported beams. 'Ihis modeling technique does not include the stiffening effects of concrete bearing at the angle ends.
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| TU Electric Comanche Peak Steam Electric Staties
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| ' bJ' A Independent Assessment Program - AE Phases 11111ll11111tll1llll1111111lll Job No. 84056 Revision 15 IUE\84056\RIL-2. MAN
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| 07/09/88 ;
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| Revision 15 i Page 184 CABLE TRAY SUPPORTS Review Issues List B. Principal Axes The principal axes were not considered in the analyses of the ;
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| base angles subjected to the various loadings. l C. Maximum Base Angle lengths Not Considered The base angle lengths due to the maximum spacing of the i Richmond Inserts were not considered in the Working Point !
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| Deviation Study.
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| D. Lack of Design Calculations for Base Angles )
| |
| l For support types D1, D2, L-A1,1-A4, SP-4, SP-6, SP 8, and Detail 11 (Drawing 2323-S0905) the design calculations do not j include an evaluation of the base angles.
| |
| Response: A. Base angle behavior was - c. died in great detail in a number of finite element models by Ebasco and Impell. The stiffening ;
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| effect of the concrete was included in these models. From these models a set of boundary stiffnesses were developed for use in the support models. The oevelopment of these values are discussed under Issue No. 3.
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| Per Reference 3, no action is required for the evaluation of stresses in the base angles. By ignoring the siffening effect of the bearing on the concrete, the calculated stress level should be conservative.
| |
| B. Ebasco indicated that the principal axes section properties will be used in the calculation of bending stresses for the base angles.
| |
| This is documented in Attachment E of Reference 4. j
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| > Attachment F of Reference 5 indicates that Impell utilizes geometric properties for base angles. However, Impell multiplies l the stress interaction ratio by a factor of 1.2 to account for the conversion to principal axes. This factor is based on a study in ,
| |
| Reference 7. Based on a review of Reference 7, Cygna questioned why the stresses at one point on the base angle, due to Mx, are combined using an SRSS combination rather than an TU Electric Comanche Peak Steam Electric Station
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| ' b''' Independent Assessment Program - All Phases lllltl1111lll11111111tl111111l Job No. 84056 Revision 15 TUE\S4056\RIl 2. MAN
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| ,u -
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| r- m-~ne--~,,-,-,,------------,,n-y-,--,-,-r-~- -y. - - - - - --.+---,r--.e-w--e --, -en - , , - ,weer_r
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| 1 I
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| 1 07/09/88 l Revision 15 J Page 185 )
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| CABLE TRAY SUPPORTS :
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| Review Issues List absolute combination (Reference 6) An absolute combination will increase the correction factors for bending stressea.
| |
| In response to Cygna's concerns, Impell revised Reference 7. In the revised calculation the SRSS combination method was not used, instead the stresses at each point were summed absolutely.
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| In determining the stresses, the actual distance from the neutral axis to the stress point was used.
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| Impell justified the factor by showing that the ratio of the principal axes bending stress to the geometric axes bending stress was less than 1.2 for the commonly used base angle sizes.
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| Cygna reviewed this calculation and accepted it (Reference 9).
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| C This is no 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.
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| D. This is no longer an issue. Per Reference 3, the design ;
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| verification of base angles is done individually for each cupport.
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| Status: A. Closed. i B. Closed.
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| C. Closed.
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| D. Closed. ;
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| 1 I
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| I I
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| I TU Electric i g[ Comanche Peak Steam Electric Station i IIlllillilitilllllIlllillilli Independent Assessment Program - All Phases Job No. 840% Revision 15 TUE\84056\RIL 2. MAN ,
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| ,_ _ _. .-__,-__,.__.,_.,~__....._.-_-.--.__..._---.--,m. -
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| 07/09/88 Revision 15 Page 1% !
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| CABLE TRAY SUPPOR'I3 !
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| Review Issues List
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| : 27. Sucoort Oualification by Similarity Gibbs & Hill Calculation Binder 2323-SCS-104C, Set 1 !
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| | |
| ==References:==
| |
| : 1. 1
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| : 2. Gibbs & Hill Calculation Binder 2323-SCS104C, Set 5 l
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| : 3. R.E. Ballard (Gibbs & Hill) letter to J.B. George (TUGCO), :
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| GTN.69361, dated August 21, 1984, with attachments
| |
| : 4. R.E. Ballard (Gibbs & Hill) letter to J.B. George (TUGCO), '
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| GTN-69377, dated Augrst 29, 1984, with attachments l
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| : 5. 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
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| : 6. Ebasco Calculation,"Comanche Peak SES Cable Tray Hanger Volume 1", Books 4 & 8, "Cable Tray Hanger Geometry Grouping", Revision 1 i
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| : 7. Communications Report between B. I;ishkari (!'3A); J. Park (Impell); J. Christoudias, D. Fong, P. Harrison, R. Alexandru, S. j Chen, F. Hettinger, J. Swanson (Ebasco); and W. Horstman, D. )
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| Leong, J. Russ, S. Tumminelli (Cygna), dated February 10, 1987, l 8:30 a.m. - 5:00 p.m.
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| : 8. Communications Report between S. Harrison (TU Electric); W.
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| Horstman et al (Cygna); and P. Harrison (Ebasco), dated May 1, l 1987, 2:30 p.m. l
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| : 9. Communications Report between G. Ashley (Impell); P. Harrison (Ebasco); S. Harrison (TU Electric); and W. Horstman et al l (Cygna), dated May 13,1987, 330 p.m.
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| : 10. Communications Report between S. Harrison et al (TU Electric);
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| P. Harrison (Ebasco); G. Ashby (Impell); and J. Russ et al (Cygna), dated September 3,1987,1000 a.m.
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| : 11. Ebasco Instruction SAG.CP34, "General Instructions for Cable Tray Hanger Analysis for CPSES, Nos.1 and 2," Revision 11 l TU Electric Comanche Peak Steam Electric Station
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| ' J' A Independent Assessment Program - All Phases 1111111ll1111111111111111ll111 Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN I
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| \
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| 07/09/88 Revision 15 Page 187 CABLE TRAY SUPPORTS Review Issues List Summary: A. Qualification by Similarity in Original Design Calculations In the Gibbs & Hill desip calculations, several support types were qualified by similarity to another support type without j showing similarity. Cypa's review of the geometry, loading, ,
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| connection details, etc. adicated that the designs were not I obviously similar, and that calculations shouk have been I provided. Supports in this category are: l L Detail A, Drawing 2323 El070001-S Reference 2 states that Detail A is similar to Case SP-7.
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| Cygna noted that the cantilever length for Detail A is greater than for SP-7 and that the anchor bolt attachment is unlike the attachment for SP-7.
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| : 2. Detail N, Drawing 2323-E10601-01-S Reference 1 states that Detail N is similar to Details 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.
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| : 3. Detail J, Drawing 2323-El-0601-01 S Reference 1 states that Detail J is similar to case B3 . Cygna noted that the member sizes used are different than those for Case B and the frame dimensions exceed the design limits for B.
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| 3
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| : 4. Detail V, Drawing 2323 E1060101-S Reference 1 states that Detail V is similar to Detail B, j drawing 2323-E1471301-S. Cygna noted that Detail B is a 4
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| 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 design technique is applied, the frame would be statically unstable.
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| B. Qualification by Similarity in the Working Point Deviation Study l
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| , TU Electric l Comanche Peak Steam Electric Statx>n i 6i b i6 A Independent Macaunent Program - All Phases l 11111llll111ll11111111lll11111 Job No. 84056 Revision 15 TUE\84056\RIL 2. MAN l
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| 07/09/88 Revision 15 Page 188 CABLE TRAY SUPPORTS Review Issues List 1
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| 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.
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| Response: A. Impell does not use similarity in the t.spport design verification.
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| Each support is evaluated individuall} based on the as built configuration. ,
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| i Per Reference 5, Ebasco does not te similarity in the same l manner previously used by Gibbs & Hill However, they do i perform "grouping" of supports as defined in Reference 6. The i grouping technique was discussed in References 5,7 and 8. !
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| Supports are grouped based on geometry, dimensions and tray loading. One enveloping support in the group is analyzed in ,
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| I order to qualify the structural members of all supports in the group. Other components of the supports (e.g., anchor bolts, base angles, welds, etc.) are evaluated individually for each support within the group.
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| During discussions with Ebasco (Reference 9), Cygna asked how Attachment Z of the Ebasco General Instructions, Reference 11, was implemented with respect to grouped supports. Ebasco's response in Reference 10, was as follows-
| |
| : a. A frequency and static analysis was performed for every support.
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| : b. If the loads from the static analysis were less than those from the analysis of the envelopmg support, the enveloping support analysis was attached to the calculation package for the individual support. If the loads from the individual support analysis were greater than those from the enveloping i support analysis, a new qualification was performed for the individual support, removing it from the group.
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| Ebasco stated that most supports will have a stand-alone package at the completion of Attachment Z activities. l l
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| B. See Response for Issue No. 27.A.
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| TU Electric Comanche Peak Steam Electric Station AbJL A Independent Assessment Program - All Phases Job No. 84056 Revision 15 111n111111ll1111ll11111111lll TUE\84056\RIL-2. MAN
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| 07/09/88 Revision 15 Page 189 CABLE TRAY SUPPORTS Review Issues List Status: A. Closed B. Closed i
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| TU Electric I Comanche Peak Steam Electric Station i
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| ' *Ill b J k Al Independent Assessment Program - All Phases I Job No. 84056 Revision 15 ll111111111111111ll11111111111 TUE\84056\RIL-2. MAN l l
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| 07/09/88 Revision 15 PaEe 190 l
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| CABLE TRAY SUPPORTS l Review Issues List i 1
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| : 28. Critical Suooort Confinurations and Lnadinen i
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| ==References:==
| |
| : 1. Gibbs & Hill Calculation Binder 2321SCS.101C, Set 1
| |
| : 2. Gibbs & Hill Calculation Binder 232SDMI SP
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| : 3. Gibbs & Hill Calculation Binder 2323-SCS-215C, Sets 2 5
| |
| : 4. Gibbs & Hill Specification 2323 ES19, "Cable Trays," Revision 1
| |
| : 5. N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO) "Cable Tray / Conduit Support Review Questions," 84056.089, oated 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 Summary: 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 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 .
| |
| width determination assumed that: (a) trays were installed with a minimum 6" horizontal spacing, (b) the distance between the siderail 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 spacmgs as small as 1" between adjacent trays, and 0" between tray siderails and the hanger flange. Reference 4 indicates that cable tray installations at CPSES allow a maximum tray width of 36".
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| TU Electric Comanche Peak Steam Ekctric Station A Ni A Independent Assessment Program - All Phases TUE\84056\RIL-2. MAN 11111111111111111111ll11ll1111 Job No. 84056 Revision 15
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| - - _ - _ - - ,-. - -.__ _._- .-.- -,....- - - - - - . . . - .. ~ . - . - - - .
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| 07/09/88 Revision 15 Page 191 CABLE TRAY SUPPORTS Review Issues List B. Tray Location on Support In the design of the frame members for trapeze supports, Gibbs
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| & Hill typx: ally, applied the loadin to the frame in a symmetric pattern. In reymwm, g the support out plans, Cygna noted 1 that the cable trays are often locat in an asymmetric fashion l on the supports. This could result in higher stresses in the ,
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| I support members and higher loads on the anchorages than considered in the design.
| |
| Response: A. The choice of critical aspect ratios for the design of generic support types is no longer an issue since all 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 by Ebasco for certain groups of similar supports.
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| See Issue No. 27 for additional details.
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| It Per Reference 6, the design verification of cable tray supports is based on the as. built support configurations. Therefore, this is no longer an issue.
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| Status: A. Closed.
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| B. Closed.
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| l 07/09/88 l Revision 15 l Page 192 l
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| CABLE TRAY SUPPORTS Review Issues List
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| : 29. Cumulative Effect of Review Iuues
| |
| | |
| ==References:==
| |
| L TU Electric, CPSES Unit 1 and Common, ' Corrective Action Program, Project Status Report: Cable Tray and Cable Tray Hangers," Revision 0
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| : 2. Communications Report between H. Schoppmann, et al (Ebasco) and W. Horstman (Cygna), dated September 23,1987,11.50 a.m. -
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| J
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| : 3. Communications Report between S. Harrison et al (TU Electric);
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| P. Harrison (Ebasco); G. Ashley et al (Impell); J. Russ et al I (Cygna), dated December 9,1987,1:30 p.m.
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| : 4. Communications Report between G. Ashley (Impell); S. Harrison et aI (TU Electric); J. Russ et al (Cygna), dated January 8,1988, 2:00 p.m. 1
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| : 5. Communications Report between S. Harrison et al (TU Electric);
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| R. Alexandru et al (Ebasco); G. Ashley et al (Impell); J. Russ et al (Cygna), dated March 18,1988,1000 a.m.
| |
| Summary: In this Review Issues List, a number of the cited issues may lead to small unconservatisms when occurring singly in a support design. Such unconservatisms may usually be neglected. However, since several of I these issues pertain to all cable tray support designs on a generic basis, their effect can be cumulative, such that the sum of many small unconservatisms may be significant. Therefore, any reevaluation of support designs should consider the cumulative effect of all pertinent Review Issues.
| |
| Response: TU Electric provided the following response in Reference 1:
| |
| This issue is resolved by the cable tray and cable tray hanger and its comprehensive l Corrective Action toProgram engineering approach design val (CAP)idation of cable trays and l cable tray hangers and by the implementation of extensive as- l built analysis, validation and test activities.
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| l The cable tray and cable tray hanger design validation procedures include coraideration of variances between the original design and as-built cable tray hanger systems, control TU Electric Comanche Peak Steam Electric Station A NJa A Independent Maraunent Program - All Phases ll111111111111ll11111ll1111111Job No. 84056 Revision 15 TUE\84056\RIL 2 MAN
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| 07/09/88 Revision 15 Page 193 CABLE TRAY SUPPORTS Review Imues List of design documents, analysis asumptions and methods, and design assumptions and methods.
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| The as-built information neccesary to verify compliance of cable trays and cable tray hangers with design criteria was obtained by walkdowns conducted by experienced Ebasco personnel trained in acwrdance with the walkdown procedures. The results were used to create as-built drawings of the cable tray and cable tray hangers. To provide additional assurance of the accuracy of the as-built drawings, TU Electric QC personnel verified these drawings to the as-built hardware in accordance with approved QC procedures.
| |
| The issues related to control of design documents have been cumulatively addressed by implementation of a OA program which covers as-built design documentation, support drawings, and design validation calculations for cable trays nd cable tray hangers in Unit 1 and Common.
| |
| Analysis assumptions and methods and design assumptions and criteria have been addressed by be development of procedures and instructions, supported by engineering studies, which have systematically considered each issue.
| |
| Additionally, an extensive test program which included component tests and full scale system dynamic tests has provided data showing the design validation approach is conservative. Thus, the actual margins of safety in the cable tray systems have been demonstrated to be much larger than ,
| |
| the margins calculated in the design validation program. l 1
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| In summary, the desip validation program has resolved the l technical issues both individually and collectively, provided as-built documentation of the cable tray system designs and confirmed the conservatism of the design validation approach through extensive testing. The design validation program assures that the desip of cable tray systems is in conformance with the AISC Specification and licensing commitments and therefore the margin of safety is aa:eptable.
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| TU Electric Comanche Peak Steam Electric Station d 8J6 A Independent Amnt Program - All Phases Job No. 84056 Revision 15 111111111ll111111111ll11ll1111 TUE\84056\RIL-2. MAN
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| I 07/09/88 Revision 15 Page 194 CABLE TRAY SUPPORTS Review Issues List Cygna has reviewed and summarized all aspects of the cable tray support design verification program. Each aspect was categorized as either conservative, unconservative or neutral Cygna found that all unconservative aspects have been addressed specifically by Impell and/or Ebasco in studies performed as a part of the cable tray program. 1 Status: Closed.
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| Page 195 l
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| CABLE TRAY SUPPORTS Review Issues List
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| : 30. Cable Trav Damoian Values
| |
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| ==References:==
| |
| L CASE /NRC Hearing Transcripts, D196, D303 D307, D318, D321, and 13454-D461
| |
| : 2. USAEC, "Damping Values for Seismk: Design of Nuclear ,
| |
| Power Plants", Regulatory Guide 1.61, October 1973 l
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| : 3. Ebasco Procedure SAG.CP.05, "Dynamic Cable Tray System Test j Specification", Revision 3 l l
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| : 4. ANCO Document No. A-00150, "rest Plan - Dynamic Testing of Typical Cable Tray Support Configurations", Revision 1
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| : 5. Impell Report No. 0942104017, "CPSES Cable Tray Analysisfrest Correlation Final Report" Revision 0 l
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| : 6. ANCO Document No. A-00181, "Final Summary Report - Comanche Peak Cable Tray Tests", Revision 3, dated February 24, 1988
| |
| : 7. ANCO Dm.ument No. A-000187, "Data Packaged for Case 7 -
| |
| Comanche Peak Cable Tray Tests, Revision 2, dated December 4, 1987
| |
| : 8. Impell Calculation TC7 PT1, Revision 1, dated December 1986
| |
| : 9. ANCO Document No. A-000186, "Data Package for Case 6 -
| |
| Comanciie Peak Cable Tray Tests, Revision 1, dated December 9, l 1
| |
| 1987
| |
| : 10. Impell Calculation C6-PT1, Revision 1, dated February 1987 l
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| : 11. Communications Report between D. Williams (QEST) and J. Russ et al (Cygna), dated July 17,1987, 2:45-7:45 p.m.
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| : 12. Communications Report between ZShi (Ebasco); R. Kaczkowski et al (Impell); and B. Atalay et al (Cygna), dated August 4 through August 6,1987, 900 500 p.m.
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| 1 TU Electric Comanche Peak Steam Electric Station AN6 A Independent A-ment Program - All Phases Job No. 8@56 Revision 15 111111111111111111111111111111 TUE\84056\RIL-2. MAN
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| : 13. Communications Report between G. Ashley et al (Impell); P.
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| Harrison (ebasco); S. Harrison (TU Electric); and J. Russ et al (Cygna), dated November 20,1987,11:30 amn.
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| : 14. Communications Report between S. Harrison (TU Electric); G.
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| et al (Impell); and J. Russ et al (Cygna), dated January l
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| : 15. Communications Report between S. Harrison (d J. Russ et alTU Electric Ashley (Impell); P. Harrison et al (Ebesco); an (Cygna), dated March 7,1988,12:00 p.m.
| |
| Summary: namping values of 4% and 7% have been used for the evaluation of JBE and SSE seismic inertial loads, respectively, in the design verification of the CPSES cable tray systenu. These damping values correspond to those recommended by Reference 2 for bolted steel structures. CASE, in Reference 1, questioned the acceptability of these values for the cable t'.4y systems.
| |
| Response: Cable tray system dynamic testing was performed in accordance with l References 3 and 4. The results of these tests, discussed in l Reference 5, validate the selected damping values.
| |
| J In addition, a study was performed, Reference 3, to correlate the I results of the testing with the analytical methods used for the cable l I
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| tray system design validation effort. One of time intents of the correlation study was to show that the predicted response enveloped the test responte when the analysis used 4% sad 7% damping (for OBE and SSE, respectively).
| |
| The dynamic test provam was also intended to prcvide added confidence to the cabc tray system qualification by demonstrating system functionality at load levels we'l in excess of the design requirements. Functionality could be proven by the following observations during tests: )
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| : a. Buckling of members did not occur
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| : b. Any pps in the tray / support system, at connection points, had no l signifmant effect on the system response l l
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| l TU Electric Comanche Peak Steam Electric Station 6N N k A Independent Assessment Program All Phases 11111111lll111ll11llll11111111Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN
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| : c. Oversize bolt holes had no significant effect on the system I
| |
| : d. Gross failure of suprorts, cable trays or loss of electrical l continuity did not occur l The test results have shown that the analyses used for the design verification are conservative with respect to the actual dynamic behavior of the cable tray syste.ms.
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| Cygna agreed that the testing demonstrated a minimum of 4% and 7%
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| dam 3ing and that the system did remain functional even when the acce cration inputs were 2 to 3 tirees greater than the acceleration input used in the design.
| |
| Cygna had numerous questions which pertained to the methods used by Impell to address items a, b and c, above. The resolution of these comments was not performed since the areas in question were meant only to demonstrate the oserall adequacy of the cable tray systems.
| |
| TU Electric stated that quantifiable results from these areas of the test program would not be used in the design validation.
| |
| Finally, Cypa raised various questions which pertained to the I inconsistences between the ANCO test packages, the ANCO final l report, Impell's data reduction packages and Impell's final report. '
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| These concerns were dim = mad and resolved Status: Closed. )
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| l l
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| TU Electric Comanche Peak Steam Electric Station A 8)a i
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| A Independent Assessment Program - All Phases l Job No. 84056 Revision 15 11ll1111111111111111ll11111111 TUE\84056\RIL-2. MAN l 1
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| l 07/09/88 Revision 15 Page 198 CABLE TRAY SUPPORTS Review Issues List ;
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| : 31. Modeline of B>undary Conditkw
| |
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| ==References:==
| |
| L CASFJNRC Hearing Transcripts 13707 and 13776 i
| |
| : 2. ANCO Testing Laboiatory, Document No. A-000150, "rest Plan - '
| |
| l Dynamic Testmg of Typical Cable Tray Support Configurations,"
| |
| Revision 1
| |
| : 3. Impell Report No. 09-0210-0017, "CPSES Cable Tray System Analysisfrest Correlations,' Revision 0
| |
| : 4. Impell Special Study No. 5.9, "Oversized Bolt Holes" Preliminary 1 Issue j 1
| |
| : 5. Gibbs & Hill, Drawing 2323-S0903, Revision 3 Summary: Gibbs & Hill's cable tray support designs for CPSES employ Hilti Kwik-bolts and Richmond Inserts for anchorage to the concrete structures. The design drawings (Reference 5) specify that the holes in the base plates or base angles are to be 1/8 inch larger in diameter than the nominal diameter of the anchor bolt. During testimony, Reference 1, CASE had questioned the behavior of those bolted connections due to the hole size and the modeling techniques used to represent the associated boundary conditions.
| |
| Response: See Response for Issue No.14.F.
| |
| Status: See Status for Issue No.14.F.
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| : 32. Conduits Attached to Cable Trays orJupggla
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| ==References:==
| |
| L Transcripts of the Cable trav Hanger Design Verification Meeting between TU Electric, Cygna, Ebasco and Impell held at the CPSES Site, January 26 and 27,1987
| |
| : 2. Ebasco Instruction SAG.CP34, "General Instructions for Cable Tray Hanger Analysis for CPSES Nos.1 and 2", Revision 11
| |
| : 3. Impell Instruction PI.02, "Dynamic Analysis of Cable Tray Systems", Revision 6
| |
| : 4. Transcripts of the Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna, Ebasco, Impell, JBA and SWEC held !
| |
| at th: CPSES Site, May 19, 1987
| |
| : 5. Ebasco Response EB-T 3029, Attachment 1, "Determination of l Dominant Frequency at Point of Conduit Attachment to a Cable l Tray Hanger," dated May 15, 1987
| |
| : 6. Communicauons Report between F. Hettinger et al (Ebasco) and S. Tumminelli et al (Cygna), dated June 26,1987,10:30 a e .
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| : 7. Communications Report between S. Harrison (TU Electric); G.
| |
| Ashley, R. Kaczkowski (Impell); D. V!illiams (QEST); and J. Russ (Cygna), dated July 10,1987,10:00 a.m.
| |
| : 8. Communications Report between S. Harrison (TU Electric): P.
| |
| Harrison, S. J. Chen et al (Ebasco); and B. Atalay, D. Leong et al (Cygna), dated July 23,1987,10:30 a.m.
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| 1
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| : 9. Ebasco Response EB-T 3426, "Revised Procedure for Kinematic Condensation," dated August 27, 1987
| |
| : 10. Communicaticas Report between S. Harrison (TU Electric); P.
| |
| Harrison (Ebaro); G. Ashley (Impell); and J. Russ et al (Cygna),
| |
| dated September 15,1987, 2:15 p.m. l
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| : 11. Communications Rep.:rt between 5. Prrison (TU Electric); P.
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| Harrison (Ebanco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated November 17,1987, 300 p.m.
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| TU Electric Comanche Peak Steam Electric Station d()L A Independent Awaunent Program - All Phases Job No. 84056 Revision 15 11111111'111111111111111ll1111 TUE\84056\RIL 2. MAN
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| 07/09/88 Revision 15 Page 200 CABLE TRAY SUPPORTS Review Issues List
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| : 12. Communications Report between S. Harrison et al (TU Electric);
| |
| R. Alexandru et al (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated March 18,1988,10.20: a.m.
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| : 13. TU Electric Procedure No. TE-FVM.CS048, "Field Verification Method, Unit i Cable Tray Selected Attributes As-built Program,"
| |
| Revision 0, Dated December 31, 1986
| |
| : 14. Ebasco Instruction SAG.CP11, "System Analysis for Cable Tray Hanger Assembly for CPSES Units 1 and 2," Revision 4
| |
| : 15. Impell Calculation M-88, "Study of Modeling Conduits Attached to Hanger," Revision 0 Summary: 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 CSD16) In Reference 1, Cygna asked the f Ilowing questions:
| |
| A. How ivere the loads from the attached conduit being considered I in the cable tray design verifications? l B. How were the loads from a conduit attached to a cable tray considered in the cable tray design verification?
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| C. Attachment U of Reference 2 indicates that cable trsy supports with conduits attached must be checked to determine the support fundam:ntal frequency at the conduit attachment location. The frequency is calculated by performing a kinematic condensation of the support model to the degree of freedom associated with the conduit attachment location. Cygna is concerned about the accuracy of a frequency analysis based on the condensation of the entire mass and stiffness matrices to a single degree of l freedom.
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| Response: A. The lumped weight of the attached conduits was 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.
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| TU Electric Comanche Peak Steam Electric Station
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| : 6. #N6 3 d Independent Assessment Program All Phases 11111111111111ll11111111ll1111 Job No. 84056 Revision 15 TUE\84056\RIL 2. MAN
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| 07/09/88 Revision 15 Page 201 CABLE TRAY SUPPORTS Review Issues List For cable tray su) ports analyzed via the equivalent static method, Ebasco considerec attachment of conduits in accordance with Attachment U of Reference 2. The loads from the conduit were calculated using the peak acceleration from sne appropriate am alified rp spectra (2% damping OBE,3% damping SSE) anc a dynamm amplification factor of ;_S.
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| For the system models analyzed by the response spectrum )
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| l method, Impell, in Reference 3, and Ebasco, in Reference 14, I included the conduit lumped weights as a part of the cable tray system model Seismic loads were developed as part of the response spectrum analysis, using 4% demping OBE and 7%
| |
| damping SSE amplified response spectra. This approach assumed that the conduit had the same damping as the cable trays rather l than the lower damping values specified for conduits in the FSAR and that the conduits were rigid (i.e. by modeling these as lumped weights the dynamic effects associated with the flexibility of the conduit spans was neglected).
| |
| To su > port this modeling technique, a study was performed in Impel. Calculation M-88. The results of the study indicate that out of various load components considered, some loading were underpredicted whereas some other loading were over predicted.
| |
| The impact of overprediction and underprediction counter balance, resulting in an acceptable prediction of the total stress interaction ratios (Reference 12).
| |
| B. According to discussions with the TU 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 to the cable tray system, will be performed by the conduit group. The tray evaluation will be by the cognizant cable tray contractos.
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| Subsequent to the above discussion, TU Electric provided the score and procedure for these walkdowns (Reference 13). Cygna rey ewed and commented on the scope of the walkdown procedure. TU Electric has revised the procedure to incorporate Cygna's comments.
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| TU Electric Comanche Peak Steam Electric Station d[JL 1 Independent Ammunent Program - All Phases 11111111111111111111lll1111111 Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN
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| C. Ebasco, in Reference 5 prepared an evaluation of the l coadensation method used in determining support frequency at j the conduit attachment location. l 1
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| As indicated in Reference 6, Cygna reviewed Ebasco's evaluation and disagreed with the applicatx>n of the Guyan kinematic condensation technique to determine the frequency of a system at a single point. Cygna's objections include:
| |
| l o A Guyan reduction is not a filtering technique (i.e., it does not allow an accurate reduction of the frequency at a specified mass point. ;
| |
| o The accuracy of the procedure depends on the mass and stiffness distribution in the system to which the condensation is applied.
| |
| 1 o The technique is especially susceptible to inaccuracies if the ;
| |
| mass distribution in the system is somewhat uniform or if, at the point of condensation, the mass is low or the point is not well supported.
| |
| Ebasco responded by stating that the condensath>n was only used as a screening techmque to determine if the frequency was less than or larger than a value of 14.5 Hz.
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| 1 Cygna presented an evaluation which showed that a Guyan reduction, as used by Ebasco could overpredict the frequency of the conduit / cable tray support system (Reference 8), Ebasco agreed and stated that they would use the first frequency of tht; combined system which had greater than 10% of the total system mass participating. Cygna stated that this was an acceptable i approach.
| |
| Subsequent to the above discussion Ebasco revised their procecure for kinematic condensation, (Reference 9) and mcorporated it in Attachment U to SAG.SP34. Cygna has reviewed this revised approach and accepted it.
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| l TU Electric Comanche Peak Steam Electric Station diJL A Independent Amnt Program - All Phases 1111111111111llllllllll1111111 Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN 4
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| : 33. As-built Walkdown Procedures
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| ==References:==
| |
| L TU Electric Procedures TNE FVM.CS001, "Field Verification Method Unit 1 Cable Tray Hanger A>Builting and Design Adequacy Verification Program", Rev. 5, July 1,1986, and TNE-FVM CS.003," Field Verification Method Unit 2 Cable Tray Han,ger As Builting and Design Adequacy Verification Program",
| |
| Revision 1, October 18, 1966. 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 the Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna, Ebasco and Impell held at the CPSES Site, January 26 and 27,1987
| |
| : 3. Nuclear Construction Issues Group, NCIG-01,"Visual Weld Acceptance Criteria", Revision 2
| |
| : 4. TUGCO Instruction QI.QP 1L10-9, "Modification, Rework and As-built Inspection / Verification of Cable Tray Hangers in Unit 1," Revision 6
| |
| : 5. Transcripts of the Cable Tray Hanger Design Verification Meeting i between TU Electric, Cygna, Ebasco, Impell, JBA and SWEC held at the CPSES Site, May 19, 1987
| |
| : 6. Impell Report No. IM P-009, "Effect of Measurement Tolerances used for Collection of As-built Data" Revision 1
| |
| : 7. Impell Report No. IM T 0210040-238, "Joint Impell/Ebasco Approach Towards Design Verification of Inaccessible Attributes, dated May 15, 1987 i
| |
| : 8. Impell Calculation M-69, "Cable Tray As-built Measurement l
| |
| ; Tolerances" Revision 0 l l
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| : 9. Transcripts of the Cable Tray Hanger Design Verification Meeting i between TU Electric, Cygna, Ebasco, Impell and SWEC held at the CPSES Site, April 21,1987 P
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| l TU Electric Comanche Peak Steam Electric Station dbJk A Independent Assessment Program - All Phases 1111111ll1111lll1lll1tllI!Illl Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN
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| 07/09/88 Revision 15 Page 205 CABLE TRAY SUPPORTS Review Issues List
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| : 10. Communications Repaq 'oetween P. Harrison et al (Ebasco); S.
| |
| Harrison (TU FLetric); and W. Horstman et al (Cygna), dated, May 1,1987, 2:30 p.m.
| |
| : 11. Communications Report between P. Harrison, R. Keilbach (Ebasco);
| |
| and W. Horstman, B. Shakibola (Cygna), dated June 22, 1987, 200 Pan.
| |
| : 12. Communications Report between S. Harrison (TU Electric); P.
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| Harrison dated (Ebasco);
| |
| September G. Ashley15,1987, p.m. 2.15(Impell); and J. Russ et al (Cyg
| |
| : 13. Communications Repost between S. Harrison (TU Electric); P.
| |
| Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated November 17,1987, 3:00 p.m.
| |
| : 14. Communications Report between S. Harrison (TU Electric); P.
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| Harrison (Ebasco); G. Ashley et al (Impell); and W. Holstman et al (Cygna), dated November 20,1987,1:15 p.m.
| |
| : 15. Communications Report between S. Harrison (TU Electric);
| |
| P. Harrison (Ebasco); R. Kaczkowski (Impell); and W. Horstman (Cygna), dated February 24,1988, 9:00 a.m.
| |
| : 16. Impell Cakulation M 75, "Relocation Tolerance for Anchor Bolts,"
| |
| Revision 1
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| : 17. Communications Report between S. Harrison et al (TU Electric);
| |
| G. Ashley et al (Impell); and J. Russ et al (Cygna); dated December 9,1987,1:30 p.m.
| |
| : 18. Communications Report between S. Harrison (Ebasco); G. Ashley .
| |
| et al (Impell); P. Harrison (Ebasco); sed J. Russ (Cygna), dated l January 11,1988,1:10 p.m.
| |
| : 19. Communictions Report between S. Harrison et al (TU Electric);
| |
| P. Harrison (Ebasco); G. Ashley (Impell); and W. Horstman et al (Cygna), dated Febnury 4,1988,1000 a.m.
| |
| : 20. Impell Calculation M 15, Attachment C, "Effect of Increwed Tension and Shear Due to Reduced Bolt Spacing" Revision 6
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| 07/09/88 Revision 15 Page 206 ;
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| CABLE TRAY SUPPORTS Review Issues List Summary: As a : art of the cable tray hanger design verification program, as-but t drawings are being deve oped for all cable tray supports. i
| |
| 'Ihese as built drawings wdl be based on engineering walkdowns !
| |
| performed in accordance with Reference L Based on a review of the procedure, Cygna raised several questions during the meeting documented m Reference 2.
| |
| A. As-built Tolerances for Dimensional Measurements Table 5 of Reference 1 provides a number of measurement tolerances for member lengths, anchor bolt spacing, etc. i I
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| L What is the basis of the given tolerances?
| |
| : 2. How are these tolerances considered in the support evaluations?
| |
| B. Cable Tray Support Walkdown Procedures / Instructions With respect to the walkdown/ inspection procedures and the
| |
| , production of as-built drawings, Cygna has the following concerns:
| |
| L What is the basis for the acceptance of VWAC, Reference 3, as the weld inspection criteria? How have these criteria been reconciled with the analysis assumptions?
| |
| : 2. Where are the dimensions for tie locations of the ends of brace members taken to? Are the dimensions used in calculating whether or not to consider the working point offset from the beam / hanger intersection taken directly in the walkdown? (See Issue No.12.)
| |
| : 3. In Section 3.2.2R7m 7.b of Referer.cc 1, what is the basis for assuming that the effective throat of full and pertial penetratxm welds is one half of sne Wycled members thickness? How will this effective throat be used in the design verification of the support?
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| I TU Electric 4
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| 07/09/88 Revision 15 Page 207 CABLE TRAY SUPPORTS Review Issues List
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| : 4. Expansion anchor types and ennbedment lengths are to be as. built. How are 111111 Super, Kwik-bolts being identified if the "star" stamp is not present or obscured by paint? How is the embedment depth determined if the length mark is obscured by paint?
| |
| : 5. Section 321R7 of Reference 1 requires that the attachments of other items to the cable tray support must be recorded.
| |
| Does the walkdown show the snethod of attachment (e.g.,
| |
| welds, bolts, etc.) of other iteras to the cable tray support?
| |
| Is the extent on any Thernv>.la If the attachment is a conduit, is thegextent on theandattachment recorded?
| |
| configuration of Thermolag on the conduit span recorded?
| |
| 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 is at the discretion of craft, this implies that their existence and location is not fully documented. Section 3.9 does not address identifying and locating tray covers. What is the basis for not considering tray covers in the development of the cable tray span sketches? How will any noted tray spacing violations be reconciled with other discipline requirements, e.g., electrical,
| |
| . damage study, etc.?
| |
| : 2. Modified tray connection platea have been identified. Will such connectxms be located? If not, why?
| |
| : 3. Will tray aiderall extensions be located? If not, why?
| |
| : 4. Will the locations and types of other components, e.g.,
| |
| conduits, light fixtures, etc., attached to the cable trays be
| |
| : identified and recorded? If not, why?
| |
| Response: A. TU Electric indicated that Reference 6 is the governing document for the acceptability of the measurement tolerances to x used during as. built walkdowns. The acceptability of these tolerances TU Electric Comanche Peak Steam Electric Station A L !k A Independent Assessment Program - All Phases ll1111llll111111111ll1111lll11 Job No. 84056 Revision 15 TUE\848%\RIl 2. MAN
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| )
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| 07/09/88 Revision 15 Page 208 CABLE TRAY SUPPORTS Review Issues List is based on a comparison of the walkdown tolerances for CPSES work to those used at other industrial facilities, as well as the PVRC recommendations for piping and pipe support walkdowns.
| |
| Cygna reviewed References 6 and 8 and had concerns on the conclusions relating to acceptability for all tolerances.
| |
| These concerns were discussed with TU Electric, Impell and Ebasco, References 12 and 14. Cygna stated that the greatest concern was with regard to the 1" tolerance on the anchor bolt location, especially for Hilti Kwik bolts. Impell replied that, in their opinion, the 1" toler:ince on the location of a typical 1" anchor bolt would not have a significant effect. Additionally, Stone and Webster (SWEC) is reporting spacing violatkms between concrete attachments with instructions. Impell stated that they had xrformed a study (Reference 16) for new anchor bolt insta.lations which showed that a tolerance of 3" on the bolt spacing and 11/2" on the bolt location were acceptable. They indi ated that this study could also be applied to the tolerances fer existing anchor bolts (Reference 14) Impell perfo med an evaluation, Reference 20, addressing Cygna's concern on the 1" measurement tolerance. This evaluation only considered Hilti expansion anchors. Richmond Inserts and mixed connections (i.e.,
| |
| Hilti expansion anchors and Richmond Inserts) are to be addressed as a part of the Civil / Structural review (Reference 19),
| |
| Cygna also expressed concern over an apparent discrepancy in the measurement tolerances for member plumbness. Reference 1 provides a 50 tolerance on the measurement of angles. However, m response to Issue No. 4.E, it was indicated that the effect of out of plumbness would be considered in the evahnstion of compression members more than 20 out-of plumb. Cygna asked how is it possible to evaluate these cases if the measurement tolerance is so large?.
| |
| 4 TU Electric indicated that the 50 tolerance does not apply to member plumbness. A special procedure was followed, TNE FVM-CS001, for measuring member plumbness. These i
| |
| measurements were performed using surveying instruments, which provide greater precision. Cygna reviewed this procedure and has i accepted it (Reference 17)L i
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| j TU Electric Comanche Peak Steam Electric Station ALJL & Independent Assessment Program - All Phases Job No. 84056 Revision 15 1111111111111111111111111111ll TUE\84056\RII 2. MAN
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| < - - - - -___ ___- ._- - _ , .m , , . . _ , . . , , , , , , _ , , , _ , , , , , _, , _ _ _ _ _ _ _ _ , , . _ _ _ , _
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| 07/09/88 Revision 15 Page 209 CABLE TRAY SUPPORTS Review Issues List B. L In Reference 2, TU Electric indicated that ttey have received NRC approval for the use of VWAC at CPSES. 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.
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| Cygna reviewed the NRC acceptance of the Visual Weld Acceptance Criteria (VWAC) and noted that the subject criteria was approved under Supplemental Safety Evaluation Report No.12 (SSER-12) Therefore, Cygna accepted applicability of VWAC to cable tray supports.
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| : 2. In Reference 2, Ebasco provided a sample of several support as-built drawings showing the measurement locations for the brace connections. He walkdown dimensions are used to calculate the working point offset for the modeling.
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| : 3. In Reference 2, Ebasco indicated that it is not possible to visually determine the weld genetration depth. Therefore, one half of the member thic(ness is used for conservatism.
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| This value is used in calculating the weld stresses. l Discussions with Ebasco on this topic are recorded in i Reference 11. See Issue No.16.I for additional discussion of j this topic, j l
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| : 4. In Reference 2, Ebasco indicated that Ultrasonic Testing 1 (UT) will be used to identify the expansion anchor type if a "star" is not visible. Embedment can also be checked by UT.
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| If UT cannot be performed or is inconclusive, the anchor bolt is treated as an inaccessible attribute in accordance with Reference 7.
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| : 5. The type of attachment, includin g its connection to the cable tray system, is identified. Procecurally, recording the extent of Dermolag is not required. Attached conduits are noted as well as their span lengths (Reference 2) Additional procedures !#e been developeo L' describe load transfer requirements between disciphnes.
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| TU Electric Comanche Peak Steam Electric Station dEJt A Independent Anamment Program - All Phases lilitillililllilli:llillililli Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN i
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| 07/09/88 Revision 15 l
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| Page 210 CABLE TRAY SUPPORTS Review Issues List ,
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| i C. Cable Tray Span Walkdowns i
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| : 1. Per discusions between Impell, Ebasco and Cypa, the i location and extent of tray covers will be identified in cable tray span walkdowns. This is a art of post QC raceway j and separation inspection oer TL Electric procedures j OI-QP 11.40 and QI-QP-11.$-29. Tray smeing violatior.s are 1 also noted and reconciled as per the a mye procedures l (Ref.~,rence 9) Impell stated that the tray covers were also )
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| considered in the cWgn verification. Cygna reviewed the 1 above procedures and accepted these as a resolution of the concern (Reference 15).
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| : 2. Modified splice connecL%s were identified during the as-built walkdowns. See Inw N x 25.C.
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| : 3. The location and extent of siderail extensions will be recorded along with the location of tray coven l (Reference 9).
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| : 4. In accordance with TU Electric Memo-2CP/C 1130, the location of other components attached to cable trays will be recorded This memo serves as a revision to wai2down procedure ECE-FVM.CS-001 (Reference 9). i I
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| Status: A. Closed :
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| B. 1. Closed
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| : 2. Closed
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| : 3. See status for Issue No.16.I.
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| : 4. Closed
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| : 5. Closed C. Closed TU Electric Comanche Peak Steam Electric Station 6.i ()6 A Independent Assessment Program - All Phases 11111111lll111111111ll11111111 Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN
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| I 07/09/88 Revision 15 Page 211 CABLE TRAY SUPPORTS Review Issues List
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| : 34. System Analysis Methodolonies
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| ==References:==
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| : 1. Communications Report between S. Harrison, J. Muffet (TU i I
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| Electric); P. Harrison Impell);
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| and N. Williams et al(Ebasco);
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| (Cygna), datedR.March Wheaton, 3,1967,B. Ramse a.m.
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| : 2. Communications Report between S. Harrison (TU Electric); G.
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| Ashley, J. Ramuta (Impell); and D. Leong et al (Cygna), dated May 14,1987,10:45 a.m.
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| : 3. Communications Re wrt between G. As:tley, C. Aboujaoude l (Impell); and B. Sha cibnia et al (Cygna), dated May 15, 1987, ,
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| 11:00 a.m. 1 1
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| : 4. Impell Calculation M 13, "Development of Seismic Overlap l Procedures," Revision 7
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| : 5. Impell Report IM P.001, "Impact of SUPERPIPE Error SP.004 on l Evaluation 176 06342," Revision 1
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| : 6. Impell Report IM P.0018, "Overlap Criteria", Revision 0
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| : 7. Communications Report between S. Harrison (TU Electric); P.
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| Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated September 24,1987, 2:20 p.m.
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| : 8. Communications Repart between J. Nandi (TU Electric); G. Ashley (Impell); and J. Russ et al (Cygna), dated November 6, 1987, 1000
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| , a.m.
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| : 9. Communications Report between S. Harrison et al (TU Electric);
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| P. Harrison (Ebasco); G. Ashley et al (Impell); and J. Russ et al (Cygna), dated November 24,1987, 220 p.m.
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| : 10. Communications Report between S. Harrison (TU Electric); P.
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| Harrison (Ebasco); R. Kazkowski (Impell); and W. Horstman (Cygna), dated February 24,1988, 900 a.m.
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| l 11. Communications Report between S. Harrisoo et al (TU Electric);
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| ! R. Alexander et al et al (Cygna), dated March(Ebasco); G.a.m.
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| 17,1988,9:00 Ashley et al (Impell); and J. Ru TU Electric Comanche Peak Steam Electric Station L*ILd6 a Indes:ndent Assessment Program - All Phases Job No. 84056 Revision 15 111111111111111111111111lll111 TUE\84056\RIL-2. MAN j
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| i
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| 01/09/88 Revision 15 Page 212 CABLE TRAY SUPPORTS Review Issues List Summary: In the process of reviewing the Impell and Ebasco cable tray system I analysis gocedures, two concerns were raised regarding the methods used to simplify the cable tray systems models. Both concerns were .
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| l presented in Reference L The first issue involves the corrective action for an error in Impell's computer program SUPERPIPE. The second involves overlap criteria used to lireak large cable tray, systems into smaller analysis probkms. See the response section for discussion of these concerns.
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| Response: A. SUPERPIPE Error SP-004 SUPERPIPE Error SP004 involves the incorrect assignment of directional masses for static load cases. For the gravity load case, the X. direction mass is need instead of the Y-direction (vertical) mass. The only points affected by this error are those lumped weights used to model omitted trays. ,
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| A coirection for the error is specified in Impell Project Instruction PI-02. Upward anc downward forces are specified to correct for the misapplied loads. However, PI.02 fails to qxcify which versions of SUPERPIPE this correction is to be app <ied to.
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| In Cygna's review of system analysis 17606302 (Reference 1),
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| partial application of the PI02 correction was made; however, the error had been corrected in the SUPERPIPE version being used for the anlysis. Cygna was concerned that, because PI02 does not limit the use of the correction to the affected SUPERPIPE versions, the gravity analyses for some problems may not be correct.
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| In Reference 5. Impell stated that the added gravity load in analysis 17606302 m conservative. Cygna agreed that this would be the case if gravity plus downward seismic were the controlling load combmation. However, if upward seismic load controls the design, the added gravity load would tend to decreene its impact. Reference 5 addresses the specific case of analysis 17606M2 and also indicates that Impell's internal I Technical Quality Review Program, under the QAM, requires a review and evaluation of the impact of computer program errors.
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| l TU Electrx: 1 Comanche Peak Steam Electric Station 6.8 E. 6 A Independent Assessment Program - All Phases ll1111ll1111111lll111111111111Job No. 84056 Revision 15 TUE\84056\RIL 2 MAN
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| ]
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| 07/09/88 Revision 15 Page 2D CABLE TRAY SUPPORTS Review Imues List B. Overlap Criteria In the development of cable tray system models, both Impell and Ebasco follow an overlap criteria. This is done in order to limit the number of trays and supports in the models to a manapable sized problem. The overlap criteria includes pure overlappmg of models, where a large system is cut into two or more parts for analysis, with each part including several supports in an overlapped region between the partial models and pnged supports, where a support with several cable trays is inclukd in several system models, each consilering only one tray on the support while modeling only the mas and stiffness of the other trays.
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| Cygna reviewed the calculations associated with the development
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| : of the overlap criteria and several sample analyses to determine the actual methods of implementation.
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| In the review of Impell systems analysis Nos. 17606302 and 1760634)1 (Reference 1), Cygna noted that there was one gang support shared by the two systems. The support loads for thus support, from the two analysea, differed by a factor of 2. To verify that the support loads calculated for the two analyses
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| , were appropriate, Cygna reviewed the overlar criteria development Impell Cakulation M D (Reference 4) Several concerns were discussed in Reference 2.
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| Several simple system models were used in M D. The results of the pattial models with overlap regions were compared to the 4 results of full models. Response spectrum analysis methods were used for all analyses. However, the partial models used Regulatory Guide L92 modal combination technique, while the full j models used the Complete Quadratic Combination (COC) technique.
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| Cygna was concerned with Impell's use of the CQC methodology,
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| ; as the CPSES FSAR specifies that Regulat Guide L92 methods be used. Im xil stated that the CQC met gave a more accurate preciction of the actual response of the system, Cygna i
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| stressed that their concern was more in regards to the CPSES licensing commitments than to the technical aspects of CQC, i
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| Impell agreed to provide additional justification for using CQC.
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| ! TU Electric Comanche Peak Steam Electric Station
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| : 6.N I. J 6 A Independent Assessment Program - All Phases tillimillililllillililllilli Job No. 84056 Revision 15 TUE\84056\RIL 2. MAN
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| CABLE TRAY SUPPOR'I3 Review Issues List l
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| Calculation M D used tray clamp loads and anchor reactions as j the basis for comparison of responses of the systems. Cygna )
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| asked why these were used instead of other response 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 quantities to the l tray supports. Cygna feels that these quantities are adequa'e fe the study. I I
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| In the review of M 13 (Reference 4), Cygna could not locate the development of the overlap factor of 1.10. The overlap criteria requires the use of a factor of 1.10 to increase support loads in the overlap region. Impell stated in References 2 and 3 that the factor was not developed in Calculation M D but was !
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| l recommended in a NUREG which contained results of a Brookhaven National laboratory study on overlap criteria in piping. The Brookhaven study indicated that the factor was only necessary in the overlap regions. Although the results of Impell's studies were not always consistent with the Brookhaven results, they decided to adopt the Brookhaven recommendations.
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| Impell pointed out that the results of the study as presented in i
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| a histogram in Calculation M D, show that there is a high
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| ; confidence that the support loads are not underpredicted by the overlap process. Cygna stated that the overlap study and the subject histogram was based on results of all supports in the system, and not just those in the overlap regions. 'Iherefore, there are a significant portion of supports mside and outside the overla 3 region which will see lower loadr. with mv 4 verlap model than t w full model (12% according to the histogram) here theCygna also noted that there were a sipificant number of cases w support loads were overestimated with the overlap model Impell 1
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| agreed to address both the overprediction and underprediction of loads in the models.
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| Cygna noted that, in the overlap study, each support Icad component was evaluated separately. That is, for a two.way i support, if either partial model gave higher results for each load j direction, the overlap criteria ras adequate. However, in Model j 6, it was shown that neither partial model alone (considering 4
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| i TU Electric Comanche Peak Steam Electric Station d
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| : 6. 8 i J 6 A Independent Assessment Program All Phases liliittilllllilitilimillilli Job No. 84056 Revision 15 TUE\840%\RII 2. MAN 1
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| l I
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| 07/09/88 Revision 15 Page 215 l CABLE TRAY SUPPORTS l Review Issues List l l
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| both loading directions) was adequate to envelop the results of the full model. In Reference 3, Impell stated that it is adequate to use the results of the partial models to evaluate the supports .
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| and that there is no need to envelop the results of the two ;
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| analyses. l In Reference 3, Cygna presented concerns reguding the j applicability of the overlap criteria development to all situations ,
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| in the plant. For example, system analysis 176 063 02 contained l three supports in a row with three common trays. Only one tray 1 was mockled in the analysis. The other trays were represented )
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| { by lumped masses. The overlap criteria development only j considers one gang support. Impell agreed to address this l concern; however, they stated that the tray would not ovide i I
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| significant coupling effects between supports. Similarl ygna noted a lack of restriction in applying the overlap cri ena to -
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| 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 longitudmal support closest to the break point, which corresponds to a longitudinal span of about 50 fee' Impell feels that this span is adequate. Cygna noed that there are instances where longitudinal supports are up to 90 feet apart. Therefore, in some instances, the overlap analysis may underpredict longitudinal loads on supports near the breakpoint. Impell agreed to respond to this concern.
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| Subsequent to the above discussion, Impell revised Calculation M 13, adding Attachment B, Revision 5. This analysis compared the results of the three partial models which included the ganged hangers with a full model of the region containing the ganged support, without extending up to the same elevation as one of the partial models. Cygna accepted the conclusions of this j analysis, but noted that, overall, Impell had used a cut off value '
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| on forces and moments that exceeded the allowable ca mcities of the cable tray clamps. Impell subsequently revised Ca culation M 13 to reflect lower cut.off values. Impell included this i l additional data in the histogram. The revised Idstogram showed !
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| pa that modelmanfues;rtial va however,model a smallvalues greatly number of overpredicted artial model values the full l
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| i
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| ;peatly underpredicted the actual forces anc momenta. However, Empell noted, and Cygna agreed, that when these underpredicted l
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| 1 1
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| TU Electric Comanche Peak Steam Electric Station I
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| A()6 A Independent Assessment Program All Phases 1111111llllll11111111111111111 Job No. 84056 Revision 15 TUE\84056\RIL 2. MAN 4
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| . - - - - . _ . . _ . - ~ , - _ - ,.-,.,n . , , . , , , _ , _ ,
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| i 07/09/88 Revision 15 Page 216 CABLE TRAY SUPPORTS Review Issues List i 1
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| quantities were included in the interaction ratio, there was no i significant affect on the interaction ratio. Based on the above, Cygna closed this issue.
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| Status: A. Closed.
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| B. Closed.
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| i l
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| i i
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| l M ~
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| 3
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| ~
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| TU Electric Comanche Feak Steam Electric Station rL N 8- ) 6 Il A Independent Assessment Program - All Phases lilllllillililllillilililllill Job No. 84056 Revision 15 TUE\84056\RIL-2. MAN
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| $ -blQ MY 0 's a D '(im 7/os /88 N
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| 'sNicts 2121 N Cai fornia Blvd . Suite 390. Watnut Creek. CA 94596 415/934 5733 July 9,1988 84056.148 hir. W.G. Counsil Executive Vice President TU Electric Skyway Tower 400 North Olive Street, LB.81 Dallas, TX 752C1
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| ==Subject:==
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| Cable Tray Support Review Issues List (RIL), Revision 15 Comanche Peak Steam Electric Station lndependent Assessment Program - All Phases Job No. 84056 References- 1. TU Electric "Generic Issues Report - Evaluation and Resolution of Generic Technical Issues for Cable Tray IIangers," Revision 2
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| : 2. TU Electric, "Project Status Report - Cable Tray and Cable Tray Hangers," Revision 0
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| ==Dear hir. Counsil:==
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| Enclosed is Revision 15 of the Cable Tray Support Review Issues List (RIL). All significant changes are indicated by a revision bar in the left margin.
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| This revision to the RIL is based on the information provided in References 1 and 2, transcripts of public meetings, documents provided by TU Electric and the results of Cygna audits up through June 30, 1988. The communications reports referenced in the RIL will be issued by Cygna within two weeks.
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| Very truly yours, O k %
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| /4 N.H. Williams 1
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| Project hianager [ h u, cA . 1 I
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| Enclosure .I
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| (
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| Boston CNcago Houston Pars'ppany Totedo Wa%t Creek TUE\84056\LTR.148
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| l sitVKEs Mr. W.G. Counsil July 9,1988 Page 2 cc: Mr. Chris Grimes (USNRC) w/ attachments Mr. D. Terao (USNRC) w/ attachments Mr. J.H. Wilson (USNRC w/ attachments Mrs. J. Ellis (CASE) w/ attachments Mr. J. Redding (TU Electric) w/ attachments Mr. L Nace (TU Electric) w/ attachments Mr. J. Muffett (TU Electric) w/ attachments Mr. R. Alexandru (Ebasco) w/ attachments Mr. G. Ashley (Impell) w/ attachments Mr. D. Pigott (Orrick, Herrington and Sutcliffe) w/ attachments l
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| TUE\84056\LTR.148}}
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