ML20151X276

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Rev 4 to Independent Assessment Program Conduit Support Design Review Issues List for Comanche Peak Steam Electric Station - Unit 1
ML20151X276
Person / Time
Site: Comanche Peak  Luminant icon.png
Issue date: 08/19/1988
From:
CYGNA ENERGY SERVICES
To:
Shared Package
ML20151X265 List:
References
PROC-880819, NUDOCS 8808250300
Download: ML20151X276 (128)
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Job No. 84056 08/19/88 Revision 4 INDEPENDENT ASSESSMENT PROGRAM CONDUIT SUPPORT DESIGN REVIEW ISSUES LIST FOR COMANCHE PEAK STEAM ELECTRIC STATION UNIT I GLENROSE, TEXAS Prepared for:

TU Electric Company Prepared by:

Cygna Energy Services 2121 North Califorma Blvd, Suite 390 Walnut Creek, California 945%

8800250300 880819 PDR ADOCK 05000 5

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8/19/88 Revision 4 Page i CONDUIT SUPPORTS Reviev> Issues List TABLE OF CONTEh"IS Issue N_g Issue Title Eags INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1. Governing Load Case for Design ...................... 3
2. Dynamic Amplification Factors . . . . . . . . . . . . . . . . . . . . . . . 7
3. Combination of Deadweight and Seismic Responses . . . . . . . . . . . . . . 15
4. Measurement of Embedment from Top of Topping . . . . . . . . . . . . . . 17
5. Bolt Ifole Tolerance and Edge Distance Violation .............. 19
6. FSAR Load Combinations ......................... 26
7. Support Self Weight ............................ 33
8. Torsion of Unistrut Members . . . . . . . . . . . . . . . . . . . . . . . . 36
9. Improper Use of Catalog Components . . . . . . . . . . . . . . . . . . . . 45
10. A nchor Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
11. Longitudinal Loads on Transverse Supports ................. SS
12. Hilti Kwik. Bolt Substitutions . .. ..................... 61
13. Substitution of Smaller Conduits on CA Type Supports . . . . . . . . . . . . 63
14. Use of CA Type Supports in LS Spans ................... 65
15. Stresses in Cable Trays Due to Attached Conduit Supports . . . . . . . . . . 67
16. Increases in Allowable Span Lengths .................... 70
17. Substitution of Next Ifeavier Structural Member . . . . . . . . . . . . . . . 72
18. Cla m p Usa ge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Tev.as Utilities Electric Qn'anche Peak Steam Electric Station

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19. Documentation Deviations Between Inspection Reports, CMCs and IN FP Drawin gs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
20. Nelson St uds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
21. Conduit Fire Protection Calculation . . . . . . . . . . . . . . . . . . . . . 94
22. Span Increase for Fire Protected Spans ... ....... .. ....... 98
23. Grouted Penetrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
24. Rigidity of CA Type Supports . . . . . . . . . . . . . . . . . . . . . . . 104
25. Enveloping Configurations for Design . . . . . . . . . . . . . . . . . . . . 106
26. Design Drawing Discrepancies . . . . . . . . . . . . . . . . . . . . . . . . 111
27. Walkdown Discrepancies .......................... 113
28. Systems Concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
29. Cumulative Effect of Review Issues . . . . . . . . . . . . . . . . . . . . 124 Texas Utilities Electric Comanche Peak Steam Electric Station

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8/19/88 Revision 4 Page 1 CONDUIT SUPPORTS Review Issues List INTRODUCTION This document summarizes the ma}'or issues which have crisen from the review of the design and installation of the conduit supports at Comanche Peak Steam Electric Station (CPSES) This review was conducted as a part of the Independent Assessment Program (IAP) performed by Cygna Energy Services for TU Electric (formerly Texas Utilities Generating Company [rUGCO)

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., assembly drawings, fabrication procedures, quality assurance procedures, etc.) generated by TU Electric and Brown & Root, Ir.c, and a walkdown of the installed conduits and conduit supports located in CPSES, Unit 1.

The Conduit 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. .

During the course of the IAP, an effort was made by the Project (Gibbs & Hill, Inc.,

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 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.

In October,1984, TU Electric created the Comanche Peak Response Team (CPRT) to develop a unified approach for the resolution of all design and construction issues associated with the licensing of CPSES A program plan was developed by the CPRT which is entitled the "CPRT Program Plan 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 conduit 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)

TU Electric contracted Ebasco Services, Inc. to perform a 100% ss-built evaluation of the conduit support designs at CPSES in accordance with DSAP VIII and the CAP. Ebasco developed a series of design criteria, work instructions and generic calculations to guide the evaluation effort and address each of the review issues. These documents are Texas Utilities Electric Comanche Peak Steam Electric Station

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8/19/88 Revision 4 Page 2 CONDUIT SUPPORTS Review Issues LLet provided as references to the "Project Status Report Conduit Supports Trains A and B, and Trains C Larger Than 2 Inch Diameter," Revision 0 (PSR)

Revision 4 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 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 conduit supports.

The resolution and closure of the issues has been an iterative process over an extended xriod of time. During this time, many of the design validation program documents have xen 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 these documents. Though the references provided in the RIL are given as the revision number u wn which issue closure is based, parts of the discussions may refer to earlier revisions of the same document.

At the time of issuance of Revision 4 of the R1L, all issues raised by Cygna have been .

addressed to Cygna's satisfaction and are closed.

Texas Utilities Electric Comanche Peak Steam Electric Station

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8/19/S8 Revision 4 Page 3 CONDUIT SUPPORTS Review Issues List

1. Governing Load Case for Design

References:

1. rUGCO), B.

Communications P.eport Bhujang (Gibbs & liill), and J. between Russ and R. Kissinger {lliams (Cygna)

N. Wi dated October 1,1984

2. CPSES FSAR, Sections 3.8.3 and 3.8.4
3. Ebasco Specification SAG.CPIO,"Unit 1 Design Criteria for Seismic Category I Electrical Ccnduit System," Revision 7
4. Ebasco Specification SAG.CP17, "Unit i Design Criterir, for Qualification of Electrical Junction Boxes, Revision 7
5. Transcripts of Conduit Supports, Cable Trays, Pipe Stress, and Pipe Supports Design Verification meeting between TU Electric, Cygna, Stone and Webster, Impell, and Ebasco dated March 24 and 25,1987
6. J. Richards (Cygna) letter to W. G. Counsil (TU Electric),

"Conduit Support Review Questions" 84056.110, dated March 18, 1987

7. Cable Tray Support Review Issue List, Revision 15, dated July 9,1988
8. Communications Report between S. liarrison et al (TU Electric); and J. Russ et al (Cygna), dated October 1,19S7, 9.25 a.m.
9. Communications Report between C.Y. Chiou et al (Ebasco) and D. Leong (Cygna), dated February 3,1988,10.00 a.rn.
10. Communications Report between J. Kuo (Ebasco) and D. Leong (Cygna), dated February 3,1988, 2:30 p.m.
11. Communications Report between S. liarrison [TU Electric) and D. Leong (Cygna), t.aed February 10,198S,3.w p.m.

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12. Communications Report between S. Harrison et al (TU Electric); CY. Chiou et al (Ebasco); and J. Russ et al (Cygna),

dated April 7,1988, 9:30 a.m.

13. Communications Report between C.Y. Chiou et al (Ebasco); J.

i Russ et al (Cygna) and S. Harrison (TU Electric), dated April 14,1988, 900 a.m.

14. Communications Report between H.S. Yu et al (Ebasco);

S. Harrison et al (TU Electric); and J. Russ et al (Cygna),

dated April 25,1988, 900 a.m.

15. SUPT-0235, "Miscellaneous Studies," Rev.1
16. SAG.CP29, "General Instructions for Design Verification of Conduit and Box Supports," Revision 4 Summary: Gibbs & Hill used the ec uivalent static method to design the conduit supports. In all :oad cases, the equisalent static -

accelerations used in designing the supports for SSE events are less than 1607e of the corresponding accelerations for 1/2 SSE (OBE) events. Based on this finding and citing Section 3.8.4 of the CPSES FSAR which allows a 607o increase in allowables for structural steel between OBE and SSE events, Gibbs & Hill determined that the design was governed by the OBE event.

To validate this conclusion, the 607o 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 Unistrut components and Hilti expansion anchors do not have increased allowables for SSE events.

By designing these catalog components to the ODE event, the manufacturer's design factor of safety is not maintained for the SSE event.

Furthermore, for the design of structural steel, the 607o increase in allowables is acceptable for axial and strong-axis bending stresses in structural members. The 60% increase cannot be applied to certain other allowable stresses. For example, the maximum increase in baseplate stresses may only be 337o, at whh;h point the material yield is reached. A limit on maximum allowable stress is not provided in the FSAR.

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8/19/88 Revision 4 Page 5 CONDUIT SUPPORTS Review Issues List These limitations were not considered in the selection of the governing seismic load case.

Response: Ebasco will perform a 100% reanalysis of conduits, conduit supports, junction boxes, junction box supports, and their components (including catalog items such as Unistrut components, Richmond Inserts and liilti expansion anchors) Critical damping values of 2%

and 3% are being used for OBE and SSE loads, respectively.

Conduits, conduit supports, and junction box supports, will be evaluated in accordance with the loads, load combinations, safety factors, and structural acceptance criteria as described in Section 4.0 of Reference 3. Member stresses are limited to 0.9 Fy under the SSE condition (Reference 5)

Junction boxes are evaluated in accordance with the loads, load combinations, safety factors, and structural acceptance criteria described in Section 7.0 of Reference 4. .

Cygna raised several questions on the allowables for axial and flexural loadings of single angles Reference 6) Ebasco's methodology for calculating axial (allowables was identical to the methodology used within the cable tray support (CTil) scope. Cygna reviewed the methodology and confirmed that the evolution of the methodology for angles subjected to twist buckling was identical to the one used in CTli scope (Reference 13) Cygna also reviewed Reference 15, in which the allowable flexural stresses for all angle sizes were calculated. The allowables were tabulated in Attachment O of SAG.CP29 (Reference 16)

Similar to the concern raised in CTli Review Issue No.1, Cygna believed that the allowable stresses for conduit support members for non-ductile failures should be limited to 2/3 Fyr. Cygna reviewed several Ebasco calculations which addressed this concern. Ebasco's calculations and responses (References S.14) indicated that axial stresses were generally not the dominant com x>nent of the conduit support member interaction ratio. Additional y, Ebasco provided a plot of the member allowables and actual support stresses. This plot showed that the actual support stresses for the SSE load cases were always less than the OBE allowables Based on the results of their I review and the actual stresses, Cygna closed this concern.

Texas Utilities Electric Comanche Peak Steam Electric Station

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8/19/88 Revision 4 Page 6 CONDUIT SUPPORTS Review Issues List Status: Closed.

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2. Dynamic Amolification Factors

References:

1. Communications Report between P. liuang (Gibbs & Ifill) and J.

Russ (Cygna), dated February 5,1985

2. Communications Report between P. Huang (Gibbs & liill) and J.

Russ (Cygna), dated February 6,1985

3. Gibbs & liill Calculation 2323-SCS 100C, Set 4, Sheets 1-11.
4. CPSES FSAR, Section 3.783.5
5. J. Richards (Cygna) letter to W.G. Counsil (TU Electric),

"Conduit Support Review Questions," 84056.110, dated March 18, 1987

6. Ebasco Specification SAG.CPIO, "Unit 1 Design Criteria for Seismic Category I Electrical Conduit System", Revision 7
7. Ebasco Specification SAG.CP20, "Unit 1, Technical Guidelines for System Analysis of Conduit Span Configurations", Revision 4
8. Communications Report between T. Alexandru et al (Ebasco) and D. Leong and B. Shakibnia (Cygna), dated June 25, 1987, 301 p.m.
9. Communications Report between li.S. Yu (Ebasco) and J. Russ (Cybna), dated July 20,1987, 315 p.m.
10. Communications Report between 11.S. Yu (Ebasco) and J. Russ (Cygna), dated July 22,1987,10.55 a.m.

1L Communications Report between R. Alexandru et al (Ebasco) and D. Leong et al (Cygna), dated July 23,1987, 5:00 p.m.

12. Communications Report between li.S. Yu (Ebasco) and D. Leong and B. Shakibnia (Cygna), dated August 10,19S7,3;00 p.m.
13. Communications Report between IIS. Yu (Ebasco) and D. Leong et al (Cygna), dated August 11,1987,1034 a.m.

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14. Communications Report between R. Alexandru et al (Ebasco) and D. leong et al (Cygna). dated August 14,1987,1:30 p.m.
15. Ebasco document SAG. TUG 1.329,' Technical Guidelines for System Analysis of Conduit Span Configurations", Revision 0.
16. Communications Report between HS. Yu (Ebasco) and B.

Shakibnia (Cygna), dated August 11,1987,1190 a.m.

17. Communications Report between C.Y. Chiou (Ebasco) and D.

Leong (Cygna), dated September 3,1987, 2:45 p.m.

18. Communications Re yrt between H. Gandhi et al (Ebasco) and D. Leong (Cygna), cated September 15,1987,1000 a.m.
19. Communications Report between S. Harrison et al (TU Electric) and D. Leong et al (Cygna), dated October 1,1987, 9.25 a.m.
20. Communications Report between H.S. Yu (Ebasco) and D. Leong ,

(Cygna), January 25,1988, 2:45 pm.

21. Communications Report between H.S. Yu (Ebasco) and D. Leong (Cygna), January 27,1988,1:30 pm.
22. Communications Report between H.S. Yu (Ebasco) and D. Leong (Cygna), January 28,1988, 4:30 pm.
23. Communications Report between HS. Yu (Ebasco) and D. Leong (Cygna), February 1,1988,1:45 pm.
24. Communications Report between F. Hettinger et al (Ebasco) and D. Leong et al (Cygna), dated February 5,1988,1:30 pm.
25. Communications Rewrt between S. Harrison (TU Electric) and D.12ong (Cygna), cated February 10,1988, 300 pm.
26. Communications Report between S. Harrison et al (TU Electric);

F. Hettinger et al (Ebasco); and D. Leong et al (Cygna), dated March 25,1988, 9:40 a.m.

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27. Communications Report between S. Harrison et al Electric);

C.Y. Chiou et al (Ebasco); and J. Russ et al (Cygna dated e April 7,1988, 9.30 a.m.

28.  ; C.Y.

Communications Chlou et al (Ebasco);Report between and J. Russ S. Harrison et al (Cygna), dated(TU Apr Electric)il 14, 1988,1:30 p.m.

29. Communications Report between HS. Yu et al (Ebasco); S.

Harrison et al (TU Electric); and J. Russ et al (vygna), dated April 25,1988, 9.00 a.m.

30. Communications Report between S. Harrison et al (TU Electric);

HS Yu et al (Ebasco); and B. Atalay et al (Cygna), dated April 27,1988, 3:15 p.m.

31. Communications Report between S. Harrison et al (TU Electric);

HS. Yu et al (Ebasco); and D. Leong et al (Cygna), dated April 28,1988,1:15 p.m. .

32. Communications Report between S. Harrison et ai (TU Electric);

HS. Yu et al (Ebasco); and D. Leong et al (CygnaN dated May 11,1988, 9.30 a.m.

33. Communications Report between S. Harrison et al (TU Electric);

F. Hettinger et al (Ebasco); and D. Leong et al (Cygna), dated May 11,1988,1.00 p.m.

Summary: Reference 4 specifies that a dynamic amplification factor (DAF) of 1.5 be used unless otherwise justified. Gibbs & Hill submitted a calculation demonstrating a DAF of 1.0 for both cable tray and conduit rurts. That calculation was based on a Class 5 piping damage study.

A reanalysis was performed for cable tray runs (see Cable Tray Review Issue 8), which established L14 as an acceptable DAF for the design of supports (with certain restrictions) Cable Tray Review Issue 25 identifies the need to perform a reanalysis to address the DAF for tray stress as well.

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O 8/19/88 Revision 4 Page 10 CONDUIT SUPPORTS Review Issues List Response: The dynamic amplification factor is implicitly included in the design "g" values to be applied to the conduit and support configurations which comprise the S-0910 package. The conduit span and design acceleration reverification plan consisted of selecting preliminary design "g" values on the basis of conduit system frequency, and confirming those values via response spectrum method (RSht) analyses of representative conduit span configurations.

For Unit 1, lower bound support frequency rec)uirements were first specified to limit the system frequency to a minimum value. The preliminary design "g" values were chosen to be either 1.5 times the peak of the floor response spectrum, if the minimum conduit system frec uency is equal to or less than the frequency at which the floor pea < acceleration occurs, or 1.25 times the value of the floor response spectrum acceleration at the system frequency, if that frequency is higher than the frequency at the peak of the floor spectrum. For the equivalent static load method of analysis (ESht),

which requires the calculation of a conduit system's natural frequency, the use of the peak acceleration multiplied by a factor is -

consistent with FSAR requirements (Section 3.7B3.5), The preliminar elevation, y design "g" values were established for each building and In order to assume that larger accelerations would not occur, Ebasco performed a series of response spectrum analyses (RSA) of various conduit run configurations. If the resulting "g" values from the RShi values, the RSA analyses accelerationswere larger were termed than design the Ifpreliminary "g's." the prelim design "g"inary "g" va were larger than the RSA accelerations, then the preliminary "g's" "g's" (Reference 9), RSh1 anayses also were performedtermed design,fic conduit systems if the generic design for speci acceleration and span requirements were too stringent.

Procedures are specified in Section 10.0 of Reference 6 for the determination of the seismic design "g" values. Reference 7 describes the methods used to design verify the allowable conduit spans and to calculate the actual "g" values at supports from RSh1 analyses results.

Actual "g" values were computed and compared to the design "g" values. The comparison generally indicated that the design "( values were appropriate. However, certain span configurations resu'ted in Texas Utilities Electric Comanche Peak Steam Electric Station

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8/19/88 Revision 4 Page 11 CONDUIT SUPPOR*IS Review Issues List accelerations greater than the design "g" values or overstress in the conduit. ,

5 If the conduit was overstressed, the conduit span without fittings was reduced based on the inverse of aquare root of the stress ratio and conduit span with fittings was reduced based on inverse of stress ratio.

If the actual acceleration at support exceeded the design "g" value, a load factor as described in sectton 5.2 of Reference 7, was applied to the support capacity.

L After reviewing the span verification and design "g" calculations, Cygna noted a number of concerns which are listed below:

Tarnet System Frequency It is Cygna's understanding that minimum target frequencies are ,

chosen for each building and floor elevation. These t4rget ,

frequencies correspond to the highest frequencies at the left side of the peaks of the three floor spectra. Minimum support frequencies are chosen to meet these minimum system frequencies (Reference 14) using the Dunkerly method.

Cygna noted that, in some of the representative analysis models, the mmimum target frequencies were not met.

Determination of Critical Models Because of the large number of parameters to consider in this study, only a limited number of permutations of those parameterr, could be analyzed. Cygna was not assured that the most critical models were used in the analyses (Reference 14).

COC Method (Comolete Ouadratic Combination)

Two modal combination methods - Regulatory Guide 1.92 and COC.

are used. Ilowever, the CQC method is not listed as an acceptable combination method in the FSAR.

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8/19/88 Revision 4 Page 12 CONDUIT SUPPOR'IS Review Issues List ,

1 Soan Stress Allowables In all span verification calculations, the conduit allowables are derived using yield stress values whl:h range up to 30 ksi.

However, the allowable yield stress in specification SAO.CP10 for the conduits is 25 ksi. Ebasco performed a generic calculation to verify that the actual stresses are below the correct allowables.

Extension of Results to Other Systems Cygna noted that the results of certain system analyses were used to qur.lify other systems without adequate justification of the variations between the two systems. For exampls, Cygna reviewed Calculation Book SPAN 1192, which validated unequal span cases for straight runs at only two elevations in the Safeguards Building (Reference 14) '

The calculation also stated that the results applied to the other configurations such as single bends, double bends, etc. Adequate justification for this assertion was not provided.

Algebraic Sum of Modes Cygna noted that the algebraic sum of modes was used to decrease the accelerations when the RSM analyses, using the Regulatory Guide 1.92 mode combination, resulted in accelerations which exceeded the design "g" values. Combination method was used because the conduit systems were purported to have mode shapes that would cancel each other. Cygna believes that the use of the above procedure is not justified, since the FSAR does not sanction this procedure. Cygna also had concerns regarding the methods' applica sility to systems I with less likelihood of moces cancelling each other.

Cygna Ebasco, and TU Electric discussed the above concerns in detail. Ebasco provided numerous calculations and revisions to the calculations for Cygna's review in order to resolve the issues (References 14 through 28) After reviewing these calculations, Cyt;na's final position was that the span verification calculations were inconclusive and did not provide a quantitative justification for the  !

conservatism in the design "g" values used in the conduit and conduit support qualification program for all systems at CPSES. As an alternate solution to Cygna's concerns, Ebasco and TU Electric proposed the study discussed in the following section.  ;

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8/19/88 Revision 4 Page 13 CONDUIT SUPPORTS Review !ssues List As a result of Cygna's poshion regarding the span verification and design "g" calculations, TU Electric and Ebasco performed a statistical sample study to demonstrate the conservatism in the design "g" values us::d in the conduit and conduit support qualification program.

The details of the study are as follows-There are approximately 5600 conduit system isometrics categorized as Seismic Class I in Unit 1. Apprcximately 2500 of these isometrics have been analyzed using the response spectrum method (RSM).

O A ranoom sample of 314 conduit system isometrics was selected, of which 106 had been analyzed by RdM. The 1% isometrics contain 506 supports.

O A comparison of the design "g" values to the computed "g" '

values for these supports indicated that all the design "g" values were larger than the computed "g" values.

O Ebasco also provided a biased engineering sample which included isometrics with configurations and elevations which were not included in the random sample study.

After review of the study, Cygna requested that some additional isometrics be added to the sample.

O Cygna completed the review of the study and accepted the method, samples, and conclusions (Referen'c es 29 through 33)

Cygna noted that the span analyses did not consider systems with unsupported junction boxes, although the weight of the junction boxes were greater than that of the BCs or LBDs. Ebasco replied that spans with unsupported junction boxes were addressed in the junction box analyses. Cygna audited representative junction box calculations and accepted the evaluation methods used (Reference 14).

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CONDUlT SUPPORTS Review Issues List Missing Mass Consideration Cygna reviewed the revision to SAG.CP25 regarding maximum mass point spacing for different conduit sizes, including conduits with Thermolag, and found the tables to be acceptable (References 17 and 2S Status: Closed.

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8/19/88 Revision 4 Page 15 CONDUIT SUPPORTS Bevicw Issues List

3. Combination of Deadweight and Seismic Resoonses

References:

1. Gibbs & Hill Calculation 2323.SCS-109C, Set 1, Sheets54-163
2. Ebasco Specification SAG.CP10, "Unit 1 Design Criteria fer Seismic Category I Electrical Conduit System,"

Revision 7

3. Ebasco Specification SAG.CP17, "Uni: 1. esign Criteria for Qualification of Electrical Junction Boxes," Revision 7
4. Communications Report between H.S. Yu et al (Ebasco); and B.

Shakibnia (Cygna), dated August 14,1987, 8:30 a.m.

5. Communications Report between S. Harrison et al (TU Electric); and J. Russ et al (Cygna), dated October 1, 1987, 9:25 a.m.
6. Communications Report between C.Y. Chiou et al (Ebasco.), and D. Leong (Cygna), dated February 3,1988,1000 a.m.

! 7. Communications Report between S. Harrison (TU Electric) and

D. Leong (Cygna), dated February 10,1988, 390 p.m.

l l Summary: In all Gibbs & Hill design calculations, the acceleration due to l 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.

Gibbs & Hill has submitted calculations which compare the acceleration vector magnitudes calculated with the standard combination method and with the SRSS method. For most buildings and elevations, the magnitude of the resultant acceleration using the SRSS method does not differ significantly from the resultant using the standard combination method. However, the difference in vector direction was not considered and is of greater importance, since each load direction contributes to different components of response in the conduit supports. To properly assess the impact of this combination method, the critical response should be evaluated instead of the l magnitude of the acceleration applied to th support.

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8/19/88 Revision 4 Page 16 CONDUIT SUPPORTS Review Issues List Response: Ebasco will not include the dead load within the SRSS combination of the seismic loads but will add its response separately in the appropriate loading combinations. Section 4.0 of Reference 2 and Section 7.0 of Reference 3 specify the load combinations used in the design verification.

Cygna d% cussed the STRUDL skeleton with Ebasco and, upon verification of several examples (Reference 6), concluded that the STRUDL skeleton and the version used for conduit supports was the same as that used for the CTH scope, which Cygna had previously accepted. Therefore, the combination of member stresses performed by the program was adequate. Additionally, for welds, baseplates, and clamps, the forces were enveloped by hand, which assured that the proper load combination was being used. ~

Status: Closed.

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4. Measurement of Embedment from Top of Toooing

References:

1. SDAR CP-80-05, "Use of Architectural Concrete in Floor Slabs," dated August 8,1980
2. N. H. Williams (Cygna) letter to W. G. Counsil (TUGCO),

"Cable Tray / Conduit Support Review Questions" 84056.094, dated October 30, 1985

3. J. Richards (Cygna) letter to W. G. Counsil (TU Electric),

"Conduit Support Review Ouestions," 84056.110, dated March 18, 1987

4. Ebasco Specification SAG.CPIO, "Unit 1 Design Criteria for Seismic Category I Electrical Conduit System," Revision 7
5. Gibbs & Hill Drawing 2323-S-0910, Sheet G-4a, Note 5a
6. DBD-CS 15, Design Basis Document, "Expansion Anchor Separation Criteria," Revision 1 ,
7. Communications Report between S. Harrison et al (TU Electric); and J. Russ et al (Cygna), dated October 1, 1987, 9:25 a.m.
8. Communications Report between HS. Yu (Ebasco) and D.

Leong (Cygna), dated January 28,1988, 4:45 p.m.

9. Cor.imunications Report between HS. Yu et al (Ebasco); and D.

Leong (Cygna), dated February 3,1988,10:00 a.m.

10. Communications Report between S. Harrison (TU Electric) and D. Leong (Cygna), dated February 10,1988, 3:00 p.m.

Summary: Note Sa on Gibbs & Hill Drawing 2323-S-0910, Sheet G-4a allows reduced expansion anchor embedment for certain supports at lower building elevations. SDAR CP-804)5 states that the integrity of the architectural topping cannot be assured, thus evaluation of all affected designs must be made to satisfy the corrective action requirements of the SDAR. Cygna has not reviewed any design calculations resolving the above mentioned note with the implications of the SDAR. The generic design calculations do not address the note.

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8/19/88 Revision 4 Page 18 CONDUIT SUPPORTS Review Issues List Such a reduction in anchor embedment is not acceptable for 1/4" and 3/8" Hilti Kwik-bolts with 2" embedment requirement, since these bolts are embedded in topping only. Additionally, Hilti does not manufacture a 1/4" Kwik-bolt of sufficient length to accommodate the 2" topping and the 2" minimum embedment in structural concrete.

The anchor embedment reduction may not be acceptable for other sizes of Hitti Kwik-bolts, depending on the actual accelerations applicable to "he floor-mounted supports versus the design accelerations. The affected support types within Cygna's scope are the CSM 18 series and CST-17.

Response: To satisfy the corrective action requirements for SDAR-CP-80-05, Ebasco will take the following action for Unit No.1:

1. All supports mounted on floors with a 2" architectural topping at elevations 832'-6" and below will be identified and design verified with a 2" reduction in embedment length. This .

reduction is in accordance with Section 7.0 of Reference 4.

2. Any 1/4" and 3/8" Hilti Kwik bolts installed in floors with topping will be replaced with a Hilti Kwik bolt having a minimum embedment of 4-1/2 bolt diameters into the structural concrete (Reference 3).
3. Reduced embedment will only be allowed with technical justification (Reference 5).

Subsequent to the above Ebasco commitments, Cygna reviewed their

, procedure for anchor bolts with reduced embedment to ensure that the requirements of DBD-CS-15 (Reference 6) were appropriately incorporated.

Status: Closed.

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5. Bolt Hole Tolerance and Edge Distance Violation

References:

1. Gibbs & Hill Drawing 2323-S-0910, Sheet G lb, Note 15
2. AISC,"Specifications for the Design, Fabrication and Erection of Structural Steel for Buildings," 7th Edition
3. Deleted
4. Ebasco Volume I, Book 22, Part 2, Item 1 "Effects of Bolt Hole Oversize in CTH and Conduit System Adequacy," Revision 6
5. ANCO Testing Laboratory, ' Test Plan Dynamic Testing of Typical Cable Tray Support Configurations", Document No.

A-000150, Revision 1, December 1985

6. Ebasco Calculation,"Comanche Peak SES Cable Tray Hanger Volume I" (The calculation books included in Volume I contain the project design criteria, general instructions, design aids, studies, computer data and usage information, and cable tray hanger grouping classification data)
7. Gibbs & Hill Drawing 2323-S2-0910, Sheet G lb, K.te 7
8. AISC, "Specification for the Design, Fabrication and Erection of Structural Steel for Buildings" 8th Edition
9. E'oasco Calculation Book 0246, "Support Verification for Cygna Issue No. 5, Bolt Hole Tolerance and Edge Distance Violation"
10. Transcripts of Conduit and Conduit Supports Design Verification meeting between TU Electric, Cygna, Ebasco, Impell, and SWEC, held at the CPSES s.te, April 21, 1987
11. Transcripts of Conduit Supports, Cable Trays, Pipe Stress and Pipe Supports Design Verification meeting between TU Electric, Cygna, Stone and Webster, Impell, and Ebasco, dated March 24 and 25,1987
12. Communications Report between HS. Yu et al (Ebasco) and B.

Atalay et al (Cygna), dated January 25,1988, 9.25 a.m.

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13. Communications Report between H.S. Yu et al (Ebasco); S.

Harrison (TU Electric); and J. Russ et al (Cygna), dated April 14,1955, 9f)0 a.m.

14. Communications Report between S. Harrison et al (TU Electric);

C.Y. Chiou et al (Ebasco); and B. Atalay et al (Cygna), dated April 26,1988, 3.15 p.m.

15. Communications Report between HS. Yu et al (Ebasco) and B.

Atalay (Cygna), dated April 28,1988, 4f)0 p.m.

16. Communications Report between S. Harrison et al (TU Electric);

HS. Yu (Ebasco); and D.K. Leong et al (Cygna), dated April 27, 1988, 3:15 p.m.

17. Communications Report between J. Muffett et al (TU Electric);

C.Y. Chiou et al (Ebasco); anc' J. Russ et al (Cygna), dated May 5,1988,1100 a.m.

18. Communications Report between S. Harrison et al (TU E'ectric);

H. Gandhi et al (Ebasco); and B. Atalay et al (Cygna), dated May 11,1988, 930 a.m.

19. Communications Report between S. Harrison et al (TU Electric);

H. Gandhi et al (Ebasco); and B. Atalay et al (Cygna), dated May 11,1988,100 p.m.

20. Communications Report between S. Harrison et al (TU Electric);

H. Gandhi et al (Ebasco); and B. Atalay et al (Cygna), dated May 12,1988,1:15 p.m.

2L Ebasco Calculation Book SUPT-0253, "Conduit Junction Box Support Design Verification Effects of Bolt Hole Oversize,"

Revision 4

22. Ebasco Calculation Book SUPT-0231,"Conduit Junction Box l Support Design Verification Method of Reducing Capacity,"

Revision 1 1

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e' 8/19/88 Revision 4 Page 21 CONDUIT SUPPORTS Review Issues List l Summary: A. Bolt Hole Oversize Reference 1 allows bolt hole tolerances which vary with the bolt size, whereas the AISC Specifications (Reference 2) provide zero bolt hole tolerances. Therefore, the bolt holes m Gibbs & Hill designs should be considered oversized and should be treated as such in bearing connection calculations.

l B. Edge Distance Violation Reference 2 requires that a minimum clear distance be maintained for oversize holes. Some Gibbs & Hill designs do not provide the minimum edge distances required in the AISC Specifications. For example, support types CA-Sa and CSM 42 provide edge distances of 3/4". Per Reference 2,25/32" is required.

C. . Bolt Interaction Calculations This issue arose duriig Cygna's audit of the Conduit Corrective Action Program. A discussion of this issue appears in the Response Section below.

Response: A. Bolt Hole Oversize

1. Ebasco performed a statistical study on the effect of bolt hole oversize on cable tray ) hanger (CTH) and conduit system -

CTH supports only. Ebasco's study concluded that the maximum bolt hole oversize present in CTHs was also applicable to conduit supports. The applicability of the study to conduit supports was justified based on the following (Reference 4)-

a. The bolt holes for all CPSES conduit and cable tray supports were fabricated by drilling, punching or teaming.
b. Both commodities were fabricated by different craft but utilizing procedures which are identical insofar as fabrication of base member bolt holes-
c. Both commodities were inspected by the same QC inspectors utilizing procedures which were the same Texas Utilities Electric Comanche Peak Steam Electric Station Independent Assessment Program - All Phases IIllitilllillfilllIllilililil Job No. 84056 \TUE\84056\23CS-ISS

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insofar as inspection of bolt hole sizes. QC was not specifically required to verify bolt hole size,

d. The material from which the supports were fabricated and the range thicknesses used was identical for both commodities.
2. Additionally, Ebasco addressed the bolt hole oversize issue in Reference 21:
a. Steel to Steel Connections TU Electric and Ebasco stated that all the steel to steel connections were upgraded to conform to the requirements of AISC Specifications.
b. Steel to Concrete Connections o Richmond Inserts .

All the conduit supports with Richmond Inserts were evaluated on a case-by-case basis in accordance with the requirements of SAG.CP25 (References 4 and 21)

' o Hilti Kwik- and Hilti Super Kwik bolts In order to determine the effect of bolt hole oversize on the base plate / angle anchorages, Ebasco selected the two-bolt base plates to be representative of the worst case. It was assumed that only one bolt would resist the shear force along the direction of the bolt axis. The two-bolt case was selected because Ebasco stated that the probability of uneven shear distribution for three or four bolt base plates / angles was very low.

Ebasco recalculated the bolt interaction ratios (IR) for all those supports with two-bolt base plate / angles and IR's greater than 0.4. The new IR's were calculated using a 5/3 exponent in the interaction equation.

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CONDUIT SUPPORTS Review Issues List All bolts were shown to have minimum safety factors of 5 and 4 for the OBE and SSE load cases, respectively (References 4 and 21).

Cygna reviewed References 4 and 21 and accepted the methods and the conclusions.

B. Edge Distance Violations

1. Edge distances in violation of AISC requirements were present in conduit support clamps, base plates, or structural steel shapes (angles / channels) This occurrence was identified in the Cygna review as well as the CTH statistical study, in which actual edge distances in clamps, angles, channels and base members of cable tray supports were measured. From the CTH statistical study, Ebasco stated that one can infer the magnitude of edge distance deviations to be expected in the conduit supports since the latter are constructed using similar components, i.e., base plates or base members, angles, channels and vendor supplied damps. The CTH statistical study concluded that:
a. for manufactured clamps, the worst case edge distance deviation would be 5/32" less than the AISC specified value.
b. for structural members, the worst case edge distance deviation would be 3/8" less than the AISC specified value for bolts larger than 5/8" in diameter and would be 1/8" less than the AISC-specified value for smaller bolt diameters.
c. base plate edge distances would have a worst case deviation of 1/8" less than the AISC-specified value.

Ebasco demonstrated that such deviations did not affect the adequacy of the cable tray supports (Ebasco Calculation Book No.13 of Reference 6)

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2. Ebasco addressed the edge distance violation issue for conduit supports in Reference 9.
a. Steel to Steel Connections See A.1.
b. Steel to Concrete Connections In Reference 9, Ebasco checked the actual edge distances shown on the Gibbs & Hill drawings for support types CA, CSM, JA, JS and CHM series. The edge distances were checked against the following-
i. the required edge distance for oversized holes based on AISC requirements.

ii. the required edge distances based on the shear capacity of the bolts.

All the supports with edge distances that did not meet the above requirements were deleted from the S-0910 drawings (References 13).

Cygna reviewed Reference 9 and accepted the methods and the conclusions.

C. Bolt Interaction Calculations After reviewing Reference 21, Cygna noted that when determining support capacities, Ebasco would reduce the loads on the base plates when the bolt interaction ratios (IR) were greater than 1.0. This reduction was accomplished by multiplying the loads on the base plates by the inverse of the IR values.

Cygna noted that the base plate behavior is nonlinear and the linear scaling of the base plate capacities would be acceptable only within a limited range of IR values (Reference 14). Ebasco provided Reference 22, in which the linear scaling of the base plate capacities

! was shown to be acceptable within the ranges specified in the calculation. Ebasco also confirmed that the maximum IR values in i

! Texas Utilities Electric g ,

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't 8/19/88 Revision 4 Page 25 CONDUIT SUPPORTS Review Issues List t the generic support calculations before reduction were below the limits specified in the calculation (Reference 20)

Cygna reviewed Reference 22 and accepted the methods and the conclusions.

Status: A. Closed.

B. Closed.

C. Closed.

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6. FSAR Load Combinations

References:

L CPSES FSAR, Section 3.8.433

2. Ebasco Specification SAG.CP10, "Unit 1 Design Criteria for Seismic Category I Electrical Conduit System," Revision 7, dated December 31, 1987
3. Ebasco Specification SAG.CP17, "Unit 1 Design Criteria for Qualification of Electrical Junctica Boxes, Revision 7, dated October 12, 1987
4. Ebasco Specification SAG.CP21, "Unit 1, Technical Guidelines for Thermal Analysis of Seismic Category I Electrical Conduit Sy, tem, Revision 3, dated October 13, 1987
5. Transcripts of Conduit and Conduit Supports Design Verification meeting between TU Electric, Cygna, Ebasco, Impell, and SWEC held at the CPSES site, April 21, 1987
6. Transcripts of Conduit Supports, Cable Trays, Pipe Stress and Pipe Supports Design Verification meeting between TU Electric, Cygna, Stone and Webster, Impeil, and Ebasco dated hfarch 24 and 25,1987
7. J. Richards (Cygna) letter to W. G. Counsil (TU Electric),

"Conduit Support Review Questions," 84056.110, dated March 18, 1987

8. Communications Report between H. Gandhi (Ebasco) and B.

Atalay (Cygna) dated July 20 and July 23,1987, 800 a.m. - 500 p.m.

9. Communications Report between H. Gandhi (Ebasco) and B.

Atalay (Cygna) dated August 11,1987, 400 p.m.

10. Communications Report between H. Gandhi (Ebasco) and B.

Atalay (Cygna) dated August 12,1987, 800 a.m.

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11. Communications Report between H. Gandhi and R. Schmidt (Ebasco) and B. Atalay (Cygna) dated August 12, 1987, 12:15 p.m. 1
12. Communications Report between H. Gandhi (Ebr.sco) and B.

Atalay (Cygna) dated August 14,1987, 900 a.m.

13. Communications Report between C Y. Chiou (Ebasco) and D.

Leong and J. Russ (Cygna) dated September 2,1987,11:45 a.m.

14. Communications Report between H. Gandhi, et al. (Ebasco) and B. Atalay (Cygna) dated September 24,1987,10:00 a.m.
15. CCL Test Report No. A-702-86, "Conduit Clamp Test Report, Phase II," dated April 7,1986
16. Communications Report between H. S. Yu (Ebasco) and B. Atalay (Cygna), dated January 28 to January 30, 1988, 9:00 a.m. to 500 p.m.
17. Communications Report betw:en S. Harrison (TU E' ctric); C.Y.

Chiou *:t al (Ebasco); and B. Atalay et al (Cygna), dated April 13,1988,130 a.m.

18. Transcripts of Conduit and Conduit Supports Design Verification meeting between TU Electric, Ebasco, and Cygna, dated April 25 through 28, 1988
19. Communications Report between S. Harrison et al (TU Electric);

C.Y. Chiou et al (Ebasco); and B. Atalay et al (Cygna), dated hiay 5,1988,1100 a.m.

20. Communications Report between S. Harrison et al (TU Electric);

H. Gandhi et al (Ebasco); and B. Atalay et al (Cygna), dated hiay 11 and 12,1988, 900 a.m.

21. Communications Report between S. Harrison et al (TU Electric),

H. Gandhi et al (Ebasco); and B. Atalay et al (Cygna), dated hiay 17,1988,10.30 a.m.

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22. Communications Report between S. Harrison et al (TU Electric);

C.Y. Chiou et al (Ebasco); and D. LeAg et al (Cygna), dated May 18,1988,1:00 p.m.

23. Communications Report between S. Harrison et al (TU Electric);

C.Y. Chiou et al (Ebasco); and D. Leong et al (Cygna), dated May 19,1988,11:00 a.m.

24. Communications Report between S. Harrison (TU Electric); H.

Gandhi et al (Ebasco); and B. Atalay et al (Cygna), dated June 2,1988, 9.10 a.m.

Summary: Cygna is concerned that all applicable loads, as defined in Reference 1, were not explicitly considered in the conduit support designs.

These concerns include loads due to pipe whip and jet impingement, as well as the use of design accelerations which do not envelop Containment Building and Internal Structure spectra.

Response: Loads resulting from pipe whip, jet impingement, missiles (including tornado missiles for externally located conduit), wind, etc., will be addressed only if the CPSES Damage Study Group determines that the affected conduits or boxes are required for safe shutdown. In those instances, the Damage Study Group informs Ebasco that the specific conduit or junction box is subject to additional loads and specifies the loads via memorandum.

Section 7.0 of Reference 2 requires the conduit system to be designed for LOCA, pipe whip, and jet impingement loads on a case-by-case basis. To date, no instances have been identified in Unit No.1.

Conduits Subiected to Tornado Loadines Conduits which are required for safe shutdown and located outdoors will be l identified. These would be subjected to tornado related loads and would be either relocated or protected by a barrier designed to resist tornado related loads (Reference 6). However, per Reference 5, these conduits and junction boxes contain cables which serve Class 1E, feedwater control and bypass l

, valves. Credit is taken for these valves in the analysis of the feedwater and main steam line breaks inside containment. Per FSAR Amendment 60, those conduits and junction boxes located outside the building, do not have to be Texas Utilities Electric Comanche Peak Steam Electric Station Independent Assessment Program - All Phases IIllilitilll!IllilllilililliJob No. 84056 \TUE\84056\23CS-ISS l

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l protected against tornado effects, since the pipe rupture events are not postulated to occur simultaneously with a tornado.

Conduits Subiected to Thermal Loadines I The load combinations specified in Section 3.8.433 of CPSES FSAR include thermal loads associated with normal operating (To) and accident condition (Ta). In addition, the FSAR specifies that accident thermal loads may be neglected when they are secondary and self-limiting in nature and the material is ductile.

For anchorages, however, the thermal loads are not secondary, hence a generic study of the thermal effects (To and Ta) on conduit and junction box supports was initiated. Results of these generic studies were incorporated in the conduit and junction box support designs.

For Unit No.1, Section 11.0 of Reference 2 specifies that thermal loads, To and Ta' must be considered in the design of the conduits and supports.

Ebasco performed generic studies on typkal systems to show that current ,

designs can accommodate thermal loads.

System Configurations Generic studies outlined in Reference 4 involve representative conduit systems up to 75'-0" in length. These systems include single run conduits with single or double bends, multiple straight run conduits, single straight run conduits with variable support stiffnesses and conduit runs with one end fixed. All conduit sizes were considered.

Thermal Loads The magnitude of thermal loads on a conduit support depends on several parameters, i.e., number of conduits, conduit size, conduit location, conduit span length and support stiffness. Studies were performed to address the relationship between the thermal load and support stiffnesses for different support member sizes as well as varying span lengths (or the number of spans in a 75'-0" conduit run).

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8/19/88 Revision 4 Page 30 CONDUIT SUPPORTS Review Issues List Sueoort Stiffness All generic seismic design calculations have assumed minimum support stiffness, which maximizes the seismic load on the system. However, this support stiffness assumption is not conservative for thermal loads, as thermal load increases with support stiffness. The thermal studies used upper bound stiffnesses to maximize thermal loads and also calculated the seismic loads which correspond to the revised system frequency. The intent was to show that the additional load is offset by the reduced seismic load. In some instances, however, the lowest of support stiffnesses (in the three directions)t were used. Cygna noted that the use of these low stiffnesses in the condui run direction did not maximize the support thermal loads. Ebasco stated that in all thermal studies, generally, the upper bound support stiffnesses have been used. In those instances where the lower bound stiffnesses were used, Ebasco added, the seismic response would be maximized, which would minimize the support capacity margin to accommodate the additional thermal loads.

Clamo and Anchor Bolt Stiffnesses .

The Unit I normal thermal analyses did not consider clamp stiffnesses.

Ignoring any slight flexibility that the clamp introduced, in determining the support stiffness, was conservative.

Anchor bolt stiffnesses were based on Teledyne test data. This test data was interpolated to estimate the stiffness for bolts which were not tested.

Cygna noted that the test data did not lend itself to interpolation due to lack of trends. Ebasco agreed with Cygna's observation. However, they noted that the bolt stiffnesses used in the support stiffness calculation had very little effect on the overall support stiffness. The bolt shear and tensile stiffnesses are very high in comparison to other components of the support, i.e., tube steel member, base plate, etc. (Reference 18),

The Unit 1 accident thermal analyses did not use clamp or anchor bolt stiffnesses. Nonlinear analyses, using the load displacement curves of clamps and anchor bolts (both obtained from test data), were performed to determine the displacements at the anchorages. Displacements which were less than 50 percent of the ultimate displacements determined for clamps and anchor bolts were considered acceptable.

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Review Issues List Cygna noted that this displacement limit was not specified in the design criteria document. Ebasco responded that SAG.CP10 was revised to contain the clamp and anchor bolt displacement acceptance criteria (References 8 and 9)

The acceptance criteria for the accident temperatures is divided into two categories-

a. Sliding of the conduit at clamp,
b. Anchor displacement.

For the condition where "a" controls, a minimum of two supports shall have factors of 2.0 on ultimate displacement of the anchorage. Using a minimum of two supports provides an additional margin for accident thermal load and also ensures that the dead load of the system is adequately supported.

For the condition where "b" controls, all supports shall have a safety factor of 2.0 on ultimate displacement of the anchors. .

The acceptance criteria were met for all supports covered in the S-0910 drawings with the following exceptions:

a. Conduit supports CSM 18h,18i,18j and all other supports (including modified and individually engineered (IN) supports) with similar anchorage, conduit support length less than 12" (along cantilever length of support) and a total conduit run exceeding 10'0", would be evaluated for accident thermal loads (Reference 2).
b. Unistrut type supports CA la, Ib, 2a, 2b, and JA1, JA2, 3A, 3B would be evaluated for accident loads when conduit ru J exceed 15'-

0", and CA-8 for all conduit runs (Reference 2).

Sunoort Capacities In thermal studies, Ebasco generally selected supports with small capacities, l among other factors, as the critical supports. The rationale behind this l selection is that the lower the support capacity is, the lower the capacity margin would be to accommodate the thermal loads. Cygna noted that'the support capacities used in the calculations did not always agree with those given in the S-0910 drawings. Ebasco acknowledged that the support capacities used were not the current ones. However, the decrease in the Texas Utilities Electric

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support capacity would result in a span reduction. With such a span l reduction, the thermal and seismic loads would change in a ccmpensating manner such that the total change in the support load would be insignificant.

Dead Load The thermal loads that were calculated based on various parameters were combined with dead and seismic loads and were compared against the support capacities. Cygna noted that in the accident thermal calculations, the dead load was not considered when determining the Hilti displacement interaction ratios (Reference 14)

Ebasco prepared a calculation to quantify the effects of the dead load. The calculation resulted in an acceptable increase in the IR value (Reference 18).

Transverse and Multi-directional Conduit Sunnorts SAG.CPIO specification requires that all conduit supports to be multi- .

directional. However, one of the controlling configurations used in the junction box thermal analyses, contained transverse supportt Ebasco xrformed a finite element analysis to address this nonconformity. Ebasco

ndicated that the previous calculation results enveloped the results of the new analysis and wete satisfactory (Reference 8).

Miscellaneous In addition to the above findings which were resolved, Cygna noted some calculation errors which are documented in References 5 through 24. These errors were corrected and the calculations were revised. Cygna completed the review of all the applicable calculations and the revisions to these calculations and accepted the methods and the conclusions.

Status
Closed.

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7. Suonort Self Weight

References:

1. Deleted
2. Ebasco Specification SAG.CP10, "Unit 1 Design Criteria for Seismic Category I Electrical Conduit System," Revision 7
3. Communications Report between S. Harrison, L. Natzic (TU Electric) and D. Leong, J. Russ (Cygna) dated October 1,1987, 9:25 a.m.
4. Communications Report between S. Harrison et al (TU Electric);

and J. Russ et al (Cygna), dated October 1,1987, 9:25 a.m.

5. Communications Report between HS. Yu et al (Ebasco) and D.

Leong (Cygna), dated February 3,1988, 5:15 p.m.

6. Communications Report between S. Hmison et al (TU Electric) and D. Leong (Cygna), dated February 10,1988, 3:00 p.m. .
7. Communicstions Report between S. Harrison et al (TU Electric);

HS. Yu et al (Ebasco); and D. Leong et al (Cygna), dated March 25,1958, 9.40 a.m.

8. Communications Report between S. Harrison (TU Eicctric), H.S.

Yu et al (Ebasco); and D. Leong et al (Cygna), dated April 14, 1988, 900 a.m.

9. Communications Report between S. Harrison TU Electric), HS.

Yu et al (Ebasco); and D. Leong et al (Cygna dated April 14, 1988,1:30 p.m.

10. Communications Report between S. Harrison et al (TU Electric);

HS. Yu et al (Ebasco); and D. Leong et al (Cygna), dated April 25,1988, 9:00 a.m.

11. Communications Report between S. Harrison et al (TU Electric);

HS. Yu et al (Ebasco); and D. Leong et al (Cygna), dated April 25,1988,1.00 p.m.

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12. Communications Report between S. Harrison et al (TU Electric);

HS. Yu et al (Ebasco); and D. Leong et al (Cygna), dated April 26,1988, 3.00 p.m.

13. Communications Report between S. Harrison et al (TU Electric); HS. Yu et al (Ebasco); and D. Leong et al (Cygna),

dated April 27,1988, 3d5 p.m.

14. Communications Report between S. Harrison et al (TU Electric); HS. Yu et al (Ebasco); and D. Leong et al (Cygna),

dated April 28,1988, id5 p.m.

Summary: Cygna's review has noted tbt support self weights were not uniformly considered in the various designs. For most CA type supports, the support weight is negligible and was not included in the calculation of support loads. For the CSht- and CST-type supports in the review scope, part or all of the self weight was neglected in the designs. The omitted self weight may be an insignificant portion of the total load on the support; however, for .

most designs, the anchor bolts are designed to an interaction ratio of LO Any additional load will produce unacceptable interaction ratios over 1.0.

In the design of the CShi 6b, CShi18 series, and CShi-42 supports, only a portion of the support weight was considered. The CSht-6b support is a braced cantilever configuration composed of Unistrut members. The weight of the cantilever member was included in the load calculation, but the weight of the brace member was neglected.

For most of the supports composed of structural tubes (CShf 18 series and CShf 42), the member length considered in the calculation of self weight was taken as the length from the baseplate to the conduit centerline. The additional length from the conduit centerline to the free end of the cantilever was neglected.

For the CST-3 and CST-17 Unistrut support designs, the total support self weight was neglected. For larger support frames, the tributary conduit weight capacity is quite small, and the self weight can be a large portion of the total load on the support.

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.g-8/19/88 Revision 4 Page 35 CONDUIT SUPPORTS Review Issues List Response: In general for all support types, Ebasco has committed to consistently include the support self weight in the design verification. This is documented in SAG.CP10 (Reference 2) Cygna's review of the ISO verification program noted that support self weight was correctly considered in all support analyses performed using computer programs.

The review of support analyses performed using hand methodologies revealed that support self weight was not properly considered in all Cases.

During this review of Calculation TNE-CS-CA-CA-15, Attachment K, Cygna noted that, the support orientation was not properly considered. Ebasco had committed to rotating each support in six orientations in order to ensure a design which would be applicable to all installations. Cygna's evaluation showed that the 3/4" diameter anchor bolts failed for the critical support orientation, despite the use of an interaction equation exponent of 5/3 (Reference 11). In response to Cygna's concern, Ebasco committed to reduce the support capacities of support type CA 15 to envelop all installation .

orientations. Cygna found this resolutico to be acceptable (Reference 13).

Status: Closed.

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8. Torsion of Unistrut Members

References:

L N.H. Williams (Cygna) letter to J.B. George (TU Electric),

"Cygna Study of Unistrut Torsional Capacity," 84056.040, dated January 18, 1985

2. N.H. Williams (Cygna) letter to W.G. Counsil (TU Electric),

"Cable Tray / Conduit Support Review Questions" 84056.094, dated October 30, 1985

3. Communications Report between R. Kissinger (TU Electric) and J. Russ (Cygna), dated January 8,1985
4. Communications Report between S. McBee (TU Electric) and J.

Russ (Cygna), dated February 21, 1985

5. Communications Report between R. Miller (CCL); R. Kissinger and S. McBee (TU Electric); and J. Russ and N. Williams (Cygna), dated February 25, 1985 .
6. Communications Report between R. Kissinger and S. McBee (TU Electric); R Miller (CCL); and D. Leong et al (Cygna), dated April 9,1985
7. Communications Report between R. Kissinger and S. McBee (TU Electric); P. Huang (Gibbs & Hill); R. Miller and R. Yow (CCL);

and D. Leong and J. Russ (Cygna), dated April 10, 1985

8. CCL Report No. A-678-85, "Seismic Qualification Test Report of Conduit Support Systems, Volume I and II," dated October 9, 1985
9. J. Richards (Cygna) letter to W. G. Counsil (TU Electric),

"Conduit Support Review Questions" 84056.110, dated March 18, 1987

10. Transcripts of Conduit and Conduit Supports Design Verification meeting between TU Electric, Cygna, Ebasco, Impell, and SWEC held at the CPSES site, April 21, 1987 l

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11. Transcripts of Conduit Supports, Cable Trays, Pipe Stress and 1 Pipe Supports Design Verification meeting between TU Electric,.

Cygna, Stone and Webster, Impell, and Ebasco dated March 24 and 25,1987

12. Communications Reports between S. Harrison and L Natzic (TU Electric); T. Kuo (Ebasco); and B. Atalay et al (Cygna),

dated August 31,1987, 9.30 a.m. and 1090 a.m.

13. Communications Report between C.Y. Chiou (Ebasco) and B. Atalay et al (Cygna), dated September 1,1987, 990 a.m.
14. TU Electric Calculation, TNE-CS-CA-CA la, "Design of Conduit Supports and Capacities of Conduit Supports" Revision 6
15. CCL Report No. A-702 86, "Conduit Clamp Test Report, Phase II," dated April 7,1986

~16. Communications Report between C.Y. Chiou and T. Kuo (Ebasco)

  • and B. Shakibnia et al (Cygna), dated September 2,1987, 2:10 p.m.
17. Communications Report between C.Y. Chiou (Ebasco); D. Leong and J. Russ (Cygna); and F. Thomas (CCL), dated September 3, 1987,190 p.m.
18. Communications Reports between T. Kuo (Ebasco) and B. Shakibnia et al (Cygna), dated September 3,1987, 200 p.m.

and 3:15 p.m.

19. Communications Report between T. Kuo (Ebasco) and B. Shakibnia and D. Leong (Cygna), dated September 4, 1987,1:10 p.m.
20. TU Electric Calculation, TNE-CS-CA JA-1, "Design of Conduit Supports," Revision 1
21. Gibbs and Hill Calculation LIS-602C, Revision 1
22. CCL Report No. A-699-85, "Conduit Clamp Test Report, Phase I," dated December 17, 1985 Texas Utilities Electric Comanche Peak Steam Electric Station Independent Assessment Program - All Phases killlllill:llfilllIllllililli Job No. 84056 \TUE\84056\23CS ISS

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23. Communications Report between S. Harrison and L Natzic (TU Electric) and D. Leong and J. Russ (Cygna), dated October 1, 1987, 9:25 a.m.  !
24. Communications Report between CY. Chiou (Ebasco) and D.

I cong et al (Cygna), dated January 29,1988, 4:30 p.m.

25. Communications Report between CY. Chiou and H.S. Yu (Ebasco) and D. Leong and B. Shakibnia (Cygna), dated February 3,1988, 5:30 p.m.
26. Communications Report between CY. Chiou and H.S. Yu (Ebasco) and D. Leong and B. Shakibnia (Cygna), dated February 4,1988, 3:15 p.m.
27. Communications Report between C.Y. Chiou et al (Ebasco) and D. Leong and B. Shakibnia (Cygna), dated February 5.1988, 1:30 p.m.
28. Communications Report between S. Harrison et al (TU Electric);

C.Y. Chiou et al (Ebasco); and D. Leong et al (Cygna), dated April 7,1988, 9.30 a.m.

29. Communications Report between CY. Chiou et al (Ebasco); S.

Harrison (TU Electric); and D. Leong et al (Cygna), dated April 14,1988,1:30 p.m.

30. Communications Report between S. Harrison and J Muffett (TU Electric); C.Y. Chiou et al (Ebasco); and D. Leong et al (Cygna), dated April 26,1988, 3:00 p.m.
31. Communications Report between S. Harrison and J. Muffett (TU Electric); CY. Chiou et al (Ebasco); and D. Leong et al (Cygna), dated April 27,1988, 315 p.m.

l 32. Communications Report between S. Harrison and J. Muffett (TU Electric); CY. Chiou et al (Ebasco); and D. Leong and B.

Shakibnia (Cygna), dated April 28,1988,1:15 p.m.

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8/19/88 i Revision 4 Page 39 CONDUIT SUPPORTS Review Issues List Summary: Torsional loading of Unistrut members is not considered in the support designs. Unistrut does not support the use of members for torsional loading. Since analysis of asymmetric sections is difficult, the members were tested.

TU Electric /Gibbs & Hill evaluated the effects of torsion in Unistrut components by a support qualification test program (References 6 and 7) Cygna personnel visited the CCL test labs (Reference 5, 6 and 7) and provided the following comments on the test scope and procedures:

L Enveloping of Conduit Supports:

a. TU Electric /Gibbs & Hill assumed that the group of tested conduit supports adequately enveloped all generic type supports at CPSES. The assumption was rnt adequately justified.
b. The conduit support test scope did not address concerns .

from the Review Issues List. When screening each support to determine the enveloping group to be used in the test scope, all npplicable concerns from the Review Issues List should be included in the comparison of design and configurational requirements.

c. The effect of applicable generic and support specific design changes should be addressed in the qualification test program.
2. Worst case support configuration and loading for the tested support:
a. The chosen member lengths, load magnitudes and directions may not be the critical case. Cygna noted that the selected configurations may not adequately address the torsional behavior of the generic support design.
b. The choice of larger diameter conduits in the testing of some supports resulted in the testing of C708-S clamps.

i P2558 clamps were not tested in the majority of the support configurations.

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c. For composite Unistrut wetions, the loading dire ( W.

should be selected to provide tensile loads on spot welds to test the integrity of the composite section.

3. Test Procedures:
a. In the visits documented in References 5 and 6, Cygna noted some discrepancies in the test set up. A yoke plate had impinged upon an outrigger, which imparted additional, unintended forces into the support.
b. :ygna also noted that the hydraulic ram which applied the t:1nsverse and vertical loads was attached in a manner such that the longitudinal conduit displacement rotated the ram from the perpendicular. Due to this rotation, a force in the longitudinal conduit direction was imparted in a direction opposite to the load applied by the longitudinal ram.
c. Strainsert bolts were used to anchor the specimens to the test fixture. These bolts were preloaded to 3200 lbs. for all test cases. Cygna was concerned that the preload used may have not been applicable for all test cases. The supports employed expansion anchors of various diameters and embedments, which implied a range of allowable bolt tensions. Additionally, use of a preload would have affected the support stiffness and hence any deflections measured in the test.

In addition to the testing scope, Gibbs & Hill was also reanalyzing supports which were not subjected to torsional loads using AISI code provisions. Gibbs & Hill intended to address the adequacy of the majority of conduit support designs utilizing Unistrut members by either testing or analysis.

Response: Test reports (Reference 8) were evaluated against all the concerns and the applicability of the test results were used in the design adequacy evaluation.

Cygna's review of the results of the conduit support test mogram produced the following evaluations and conclusions-Texas Utilities Electric Comanche Peak Steam Electric Station

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Review Issues List l A number of the tested Unistrut configurutions exhibited significant reduction in capacity. Therefore, all such Unistrut configurations were replaced and will no longer be used in the project.

Only the last four support tests (G13-T, cases 1 and 2), G14-T, G15-T and G1GT configurations) were setained. The tut configurations corresponded to supports CA la (G13-T, cases 1 and 2), CA 2a (G14-T), JA-1 (G15 T) and JA-2 (Gl&T) These four tests were performed on site and were installed in concrete rather than using the Strainsert bolts (Reference 12).

Supports CA 8 and JA 3 were qualified by comparison to support types CA la and JA 2, respectively which were tested. Support CA 2b was qualified via calculation to the requirements of the American Institute of Steel and Iron (AISI) Code.

The above mentioned supports were the only generic Unistrut supports which were retained in Unit 1. Individually engirieered (IN)

Unistrut supports not retained in the program. None of the retained .

generic supports contained P1001 C3 Unistrut member (Reference 10).

A discussion of Cygna's review of the individual test cases appears below.

G13-T Test Conficuration o Loading Direction For cans 1 and 2, Cygna noted that the conduits were loaded in a direction perpendicular to the conduit with only one load cell. Hence, this load cell input loads into the conduits in only one direction. Cygna noted that if the conduits had been loaded in opposite directions from each other, the pullout force induced l into the middS anchor bolt would have increased (Reference 16)

Ebasco performed a finite element analysis of a configuration representing the test case. This analysis resulted in bolt interaction values less than 1.0 and Unistrut stresses less than l the allowable stress of 29.7 ksi (Reference 24) These values of bolt interaction and Unistrut stress resulting from the finite l

element analysis were used as the allowable values for other t

l finite element analyses with configurations similar to the test Texas Utilities Electric Comanche Peak Steam Electric Station J' A Independent Assessment Program - All Phases

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o' 8/19/88 Revision 4 Page 42 CONDUIT SUPPORTS Review Issues List case. The above allowables were used by Ebasco in performing additional finite element analyses to determine the support capacity for varying loading directions, conduit sizes and the anchor bolt spacings as allowed in the S-0910 drawings (Reference 24).

o Outrigger Bolts Test co.ifiguration G13T, cases 1 and 2, did not have their outriggers bolted to concrete. However, the actual as-built configurations for support types CA la and CA lb do have their outriggers bolted to concrete.

Ebasco stated that lowest allowable capacity was governed by the configuration where the outriggers were not bolted to the concrete. Ebasco added that if bolted outriggers were used, the capacity would increase greatly. Cygna agreed with Ebasco's rationale. Cygna expressed concern over the behavior of the 1/4" diameter Hilti Kwik bolts (Reference 16) and their impact on '

the allowable loads of the adjacent bolts when spacing violations exist between the bolts (Reference 24 and 25).

Ebasco replied that after review of the tensile capacities of the adjacent bolts, it was established that except for the 1/2" and 1" diameter Hilti Super Kwik boits (HSKB), for all other bolt sizes, the tensile capacities due to the slip mode of failure would govern. Therefore, any reductions in the allowable loads of the bolts adheent to the 1/4" diameter Hilti Kwik bolts, present in the outriggers of the supports CA la aad CA lb, were not required (References 28 and 30) Ebasco revised the S-0910 drawings and the calculations (Reference 14) to reflect the above.

Cygna reviewed the revisions to the S-0910 drawings and the calculations and accepted the methods and the conclusiou (References 28 and 30).

G14-T Test Conficuration The G14-T configuration was tested with one conduit installed between two Unistrut brackets (one bay) Cygna noted that the S-0910 drawings for support types CA 2a and CA 2b include details for two or three Unistrut brackets with one or ore na Texas Utilities Electric Comanche Peak Steam Electric Station

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4 8/19/88 Revision 4 Page 43 CONDUIT SUPPORTS Review Issues List conduits installed between every two brackets (two bay) Cygna expressed concerns regarding the extension of the results from the one bay test to support configurations with two or more bays.

Similar to the G13T test configuration, Ebasco performed a finite element analysis representing the G14-T configuration.

This analysis of a one bay configuration using test loads, derived stresses in the Unistrut members and interaction ratios in the Hilti Kwik bolts. Stresses in the Unistrut members controlled the capacity. Ebasco, at Cygna's request, performed an analysis of a two bay configuration (Reference 14) This analysis showed that the Hilti Kwik bolts controlled the design and had inte action ratios greater than the Kwik bolt interaction ratios in the one-bay case. Ebasco agreed to reduce the allowable loads for the two bay case so that the Kwik bolt interaction ratios for the one bay case were not exceeded (Reference 24)

Cygna reviewed the calculations and accepted the methodology '

and the conclusions.

Q15-T Test Configuration The test configuration which consisted of one Unistrut with a junction box bolted to it, used the maximum eccentricity between the junction box center of gravity and the Unistrut member that was allowed on the original S-0910 drawing. Ebasco indicated that the test capacities were very low and that many of the supports were modified (Reference 12) Ebasco noted that durmg the testing, the edge of the 1" plate used to represeta the junction box was bearing against concrete which induced unintended loads, e.g., prying action into the Unistrut and the anchor bolts. Ebasco then performed a finite element analysis of a model representing the test case. The analytical model for this analysis consisted of a channel section without the Unistrut lips. Cygna noted that the analytically computed stresses exceeded the allowables and the bolt mteraction ratio exceeded 1.0 (Reference 20) Ebasco reduced the allowable support capacities so that the stress and bolt interaction ratios were below unity and issued a DCA which reflected the change. Cygna l accepted Ebasco's methodology and conclusions.

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CONDUIT SUPPORTS Review Issues List G16-T Test Configuration The tested configuration consists of a Unistrut frame bolted to the concrete with a junction box attached (Reference 12). Cygna noted discrepancies between the junction box sizes showed on the S-0910 drawings and those covered by the tested configuration and the capacity calculations. Ebasco revised the S.0910 drawings to reflect the junction box sizes considered in the tests and the calculations (Reference 18).

Cygna reviewed the calculations (Reference 20) and accepted the methodology and the conclusions.

State:i; Closed.

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9. Imoroper Use of Catalog Components

References:

1. Communications Report between P. Patel et al (Gibbs & Hill) and J. Russ et al (Cy3na) dated September 20, 1984
2. Communications Report between R. Kissinger (TUGCO) and N. Williams (Cygna) dated October 11, 1984
3. Communications Report between E. Irish (Unistrut) and D. Leong and J. F u (Cygna) dated January 21, 1985
4. Communications Report between E. Irish (Unistrut) and D. ceong and J. Russ (Cygna) dated February 4,1985
5. Gibbs & Hill Calculation 2323-SCS153C, Sheet 1/37
6. Deleted
7. AISC hianual of Steel Construction,7th Edition including Supplement Nos.1, 2 and 3
8. J. Richards (Cygna) letter to W. G. Counsil (TU Electric),

"Conduit Support Review Questions," 84056.110, dated h1 arch 18, 1987

9. Unistrut General Engineering Catalog No. 9
10. AISI, Cold Formed Steel Design hianual,1983 Edition
11. Gibbs & Hill Specification No. 2323-SS-30, Revision 2, dated June 13,1986 l 12. Ebasco Specification SAG.CP2, "Unit 2 Design Criteria for l Seismic Category I Electrical Conduit System," Revision 9, dated hfarch 27, 1987

! 13. CCL Report No. A-699-85, "Conduit Clamp Test Report, Phase I," dated December 17, 1985

14. CCL Report No. A 702-86, "Conduit Clamp Test Report, Phase II," dated April 7,1986

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15. Communications Report between HS. Yu et al (Ebasco) and J.

Russ (Cygna), dated July 21,1987,10:30 a.m.

16. Communications Report between S. Harrison et al (TU Electric); and J. Russ et al (Cygna), dated October 1,1987, 9.25 a.m.

Summary: A. In addition to Cygna's comments on the implicit increase in allowables for SSE loads (see Review Issue 1), Cygna has other concerns regarding the support designs using catalog components.

AISC-derived allowables are used in the design process. These values are generally conservative for bending, but are generally unconservative for axial allowables, as catalog allowables are based on the AISI Code which considers buckling of thin, open sections.

Examples of Cygna's concern are diccussed below: -

o CSM-6b: 20 ksi was used for Fa, the axial allowable.

This value is equal to .6 Fv, where Fy = 33 ksi and was used for any memb:r length without considering slenderness effects. Catalog values range from 5.77 ksi for a brace length of 60" to 13.9 ksi for a 24" brace.

o CST 3: The design employed the AISC table of axial stress allowables for 36 ksi steel.

o CST 17: The design employed the AISC tables of axial stress allowables for 36 ksi steel. The table value was then reduced by a ratio of 33/36.

B. Components were used in ways not intended by the vendors.

Cygna concerns in this area are as follows:

o Allowables are not listed for P1001C3 sections in the Unistrut catalog. Member properties are given for the X-Y axes instead of the principal axes. Discussions with Unistrut indicate that the uses of P1001C3 are unique with respect to load application and member restraint. '

Texas Utilities Electric Comanche Peak Steam Electric Station Independent Assessment Program - All Phases u' nlillitilHlitilitillii Job No. 84056 \TUE\84056\23CS ISS

8/19/88 Revision 4 Page 47 CONDUIT SUPPORTS Review Issues List Thus, no generic allowables can be provided. Unistrut places the burden on the designer to properly consider the capacity of the section for its intended use. Gibbs & Hill has not provided adequate evaluation of these members.

o The Unistrut catalog indicates that the intended use of P1325, P1331, P1332 brackets is for single members in a pinned connection. Gibbs & Hill uses two brackets on double members, which Cygna believes to be a moment resisting connection. Gibbs & Hill considers these connections pinned for some brackets in CSM-6b, CST 3, and CST-17 supports. Unistrut does not provide allowables for this bracket configuration.

o Gibbs & Hill references Unistrut Test C-49 to obtain allowables for the double bracket connection in CST-3.

The designed connection is subject to tensile and shear loads. The test provided data for loading the bracket in tension only. Gibbs & Hill compared the calculated tensile load to the allowable, ignoring the calculated shear, o P1941 plate connectors are used to connect headers to outriggers in CA la and CA 2a supports. Gibbs & Hill calculations indicate that tightening the Unistrut bolts to the specified torque overstresses the plate and causes excessive bowing of the plate. Discussion with Unistrut indicates that these connectors are to be used to construct frames where the connected members are restrained at both ends. Clarification of this concern is required for CA la and CA 2a supports, since the member end restraint required by Unistrut has not been provided.

Evaluation of the connection to transfer the required load was not performed. In Revision 1 of Gibbs & Hill Drawing 2323-S-0910, Sheet CA la, Note 7 was added to provide P10M plates if bending of the P1941 plates occurs. In Gibbs & Hill Calculation 2323-SCS153C, Sheet 1/37, a discussion of field installation practice documents that the P10M plates do not reduce the bowing of the outriggers. Unistrut tests showed no bowing of the outriggers when the P10M plates were used.

Verification of the bolt torques used in the test set up is required.

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8/19/88 Revision 4 Page 48 CONDUIT SUPPORTS Review Issues List o Four types of Superstrut clamps are specified for use on conduit supports: C708, C708 U, C708-S, and modified C708-S (see Review Issue 18 designed for three directiona). These clamps are notl load capacity. Allowables for tensile loading only are given in the Superstrut Catalog.

Response: Supports constructed of Unistrut components have been qualified by either testing or analysis employing the methods of the AISI Specifications (Reference 10) Alternatively, those Unistrut supports in configurations which have neither been tested nor analyzed, or have been shown by test to have unacceptable capacities will be replaced. For Unit 1, all Unistrut supports with the exception of CA 1, CA 2, CA-8, JA 1, JA 2, JA 3, CLS 3, and CLS-4 will be replaced. Generic transverse supports will be replaced entirely or will become individually engineered (IN) supports. As a result, Cygna's concerns with support types CSM-6b, CST 3, and CST-17 are no longer relevant. Removal of the CSM-6b configuration and other .

similar supports also removes Cygna's concerns regarding the use of P1001C3 Unistrut sections.

Testing com imed that bowing of the P1941 plate connectors did not occur when the Unistrut bolts were tightened to the specified torque.

This behavior is further confirmed by observation of installations m the field.

Fiaally, clamps (both Unistrut and Superstrut) have been shown by test (References 13 and 14) to resist loadings in three directions.

Ilowever, the capacity of one specific clamp (C-70S-S) has been shown to be inadequate for certain applications. Consequently, all C-708-S clamps for 4" and larger conduits will be replaced or shown to be adequate for the specific installation. <

The presence of C-708-S clamps on 4" and larger conduits has been identified via a walkdown of all power and control conduits (lighting conduits are all less than 4" in diameter) in the Unit 1 and Common areas. There are a total of 407 C-708-S clamps in the Unit 1 and Common areas. Cygna finds the approach acceptable.

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8/19/88 Revision 4 Page 49 CONDUIT SUPPORTS Review issues List Status: A. Unistrut Allowables See Review Issue 8. Closed.

B. Unistrut/Superstrut components See Review Issues 8 and 18. Closed.

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10. Anchor Bolts

References:

L N.H. Williams (Cygna) letter to J.B. George (TUGCO), "Cable Tray and Conduit Support Review Questions," 84056.015, dated August 6,1984

2. N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO), "Cable Tray / Conduit Support Review Questions" 84056.094, dated October 30, 1985
3. Gibbs & Hill Calculation 2323-SCS.153C, Set 1, Sheets 32-44
4. Gibbs & Hill Calculation 2323-SCS153C, Set 1, Sheets 146-152
5. Ebasco Specification SAG.CPIO, "Uriit 1 Design Criteria for Seismic Category I Electrical Condrit System," Revision 7
6. Ebasco CPSES Cable Tray Hanger Volume I. The books included in Volume I contain documents consisting of the '

project design criteria, general instructions, design aids, studies, computer data and usage information, and cable tray hanger grouping classification data

7. Ebasco CPSES Unit 1, General Instructions for Electrical Cond iit and Box Supports, Revision 0, dated July 15, 1986
8. J. Richards (Cygna) letter to W. G. Counsil (TU Electric),

"Conduit Support Review Questions" S4056.110, dated March 18,1987

9. Transcripts of Conduit Supports, Cable Trays, Pipe Stress and Pipe Supports Desiga Wrification meeting between TU Electric, Cygna, Stone and Webster, Impell, and Ebasco, dated March 24 and 25,1987
10. Brown and Root Procedure CEI 20, "Installation of Hilti Drilled-In Bolts," Revision 9, dated December 16, 1983
11. Ebasco Calculation TNE-CS CA-CA la, "Design Capacity of Condeit Supports" Rension 5 l

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12. SWEC Document DBD-CS15, "Design Basis Document -

Expansion Anchor Separation Criteria," Revision 1

13. Gibbs & Hill Specification No. 2323-SS-30, Revision 2, dated June 13,1986
14. Communications Report between C.Y. Chiou (Ebasco) and D. Leong et al (Cygna), dated September 1,1987, 900 a.m.

15.

Communications and S. Harrison and Report L. Natzicbetween D., Leong)and (TU Electnc dated J. Russ (Cygna)

October 1,1987, 9.25 a.m.

16. Communications Report between HS. Yu et al (Ebasco) and D.

Leong (Cygna), dated February 3,1988,10:00 a.m.

17. Communications Report between S. Harrison (TU Electric) and D. Leong (Cygna), dated February 10,1988, 3:00 p.m.
18. Communications Report between S. Harrison et al (TU Electric); HS. Yu et al (Ebasco); and D. Leong et ai (Cygna),

dated March 2,1988, 9:40 a.m.

19. Communications Report between S. Harrison et al (TU Electric); HS. Yu et al (Ebasco); and D. Leong et al (Cygna), i dated March 25,1988, 9:40 a.m.
20. Communications Report between S. Harrison et al (TU Electric);

HS. Yu et al (Ebasco); and D. Leong et al (Cygna), dated April 7,1988, 9 30 a.m.

21. Communications Report between S. Harrison (TU Electric); HS.

Yu et al (Ebasco); and D. Leong et al (Cygna), dated April 14, 1988, 9:00 a.m.

22. Communications Report between S. Harrison et al (TU Electric);

HS. Yu et al (Ebasco); and D. Leong et al (Cygna), dated April 25,1988, 9:00 a.m.

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23. Communications Report between S. Harrison et al (TU Electric); HS. Yu et al (Ebasco); and D. Leong et al (Cygna),

dated April 26,1988, 3:00 p.m.

24. Communications Report between S. Harrison et al (TU Electric); HS. Yu et al (Ebasco); and D. Leong et al (Cygna),

dated April 27,1988, 3:15 p.m.

25. Communications Report between S. Harrison et al (TU Electric); HS. Yu et al (Ebasco); and D. Leong et al (Cygna),

dated May 11,1988, 9:30 a.m.

l

26. Communications Report between S. Harrison et al (TU Electric); HS. Yu et al (Ebasco); and D. Leong et al (Cygna),

dated May 11,1988,1.00 p.m.

Summary: Cygna has the following concerns regarding anchor bolt designs:

A. For the conduit support designs reviewed, Gibbs & Hill was .

inconsistent in the treatment of prying of concrete attachments on anchor bolt tension. The increase in anchor bolt tension was handled in one of three ways:

o In some support designs, prying was neglected.

o For most supports with baseplates, a prying factor of 1.5 was used. For this case and the one above, justification for the assumed prying factor or the lack thereof was not provided by Gibbs & Hill.

o In a few other support designs, the method on pages 4-89 to 4-90 of the 8th Edition AISC Manual of Steel Construction was used to justify the use of a prying factor of 1.0. For this case, justification of the applicability of the method is required, since the concrete attachments in the conduit support designs differ from the steel-to-steel connections addressed in the 5th Edition method.

B. The concrete connections for conduit support CST 17, Type 17 consist of box brackets around the P5000 header members, through which the Hilti Kwik bolts pass. The header is 3.25" Texas Utilities Electric j Comanche Peak Steam Electric Station Independent Assessment Program All Phases bilitililitilllitilllililli Job No. 84056 \TUE\84056\23CS ISS

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8/19/88 Revision 4 Page 53 CONDUIT SUPPORTS Review Issues List deep, and the anchor bolt is loaded at a considerable distance above the concrete surface. The Gibbs & Hill design does not consider moments induced in the anchor bolt due to shears applied above the concrete surface.

C. In the design of CA 2a supports, Gibbs & Hill assumed that longitudinal forces on the conduits are resisted only by the outriggers bearing on the concrete surface. Because of this assumption, the Hilti Kwik-bolts in the outriggers do not carry any load; however, the anchors may carry some load due to the conduit loads and also due to prestressing of the support by the cinching of the bolts in the P1941 and P1064 plates connecting the header and outrigger. Additionally, the current revision of the CA 2a design drawing waives proximity violations between the Hilti bolts in the outriggers and any other anchor bolts. If these bolts are evaluated for loads, large, capacity reductions will be required for the spacing provisions in the design.

D. Note 3 on Gibbs & Hill Drawing 2323-S-0910, Sheet G-4a allows substitution of 1" diameter Richmond Inserts for 1" diameter and smaller Hilti Kwik- and Super Kwik. bolts. In general, singly installed Richmond Inserts have a higher capacity than Hilti Kwik and Super Kwik bolts; howcVer, Richmond Inserts in clus:er arrangements may have lower capacities. The Gibbs &

Hill designs do not consider or evaluate Richmond Inserts.

E. Cygna expressed concerns regarding Ebasco's use of the EZHANG computer program for the evaluation of base plates and welds. These issues as well as concerns regarding 1/16" gaps under base plates are discussed in Response Section below.

Response: A. Cygna noted that, in Section 8.0, paragraph 2, Item a. of Ebasco Calculation Book 8, prying is not explicitly included in the interaction formula (Reference 8) Ebasco stated that the qualification of concrete anchorages for generic base plates and base angles was performed in accorcance with SAG.CP10 (Reference 5) in Ebasco Calculation Book 133, Volumes 1 through 23 (Reference 6).

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8/19/88 Revision 4 Page 54 CONDUIT SUPPORTS Review Issues List Section 7.0 of Reference 5 specifies that prying action shall be included in the design verification of concrete anchorages.

Prying action will be considered by performing generic finite element analyses for various sizes of base angles and base plates. The interaction between the flexibility of the base angle (or base plate), the anchor bolt stiffness, and the concrete stiffness was considered. Section 9.0 of Ebasco Calculation Book No. 60 contains the study of prying action and is applicable to only Hilti Kwik-bolts (Reference 9).

Prying factors have been established by summarizing the generic base plate finite element analysis results. When the analyzed base angle or base plate configurations are not applicable to a specific design, an individual analysis is performed in the design verification. Prying factors for various sizes of base angles and base plates are established in Reference 6. The results of this study are included in Reference 7.

Ebasco developed prying factors fos cases where different components of loads are applied to the plate. These calculations were located in Attachments B and G of Calculation Book 60 (Reference 9) Cygna asked whether Ebasco developed genetic prying factors for base plates with Hilti Kwik bolts and Richmond Inserts (Reference 8). These connections will be analyzed on a case by case basis (Reference 9).

B. Conduit support CST 17 will be replaced, modified, or individually qualified in specific applications; hence, Cygna's concern is no longer relevant. If a portion of this support type is left in place, documentation will be provided to show

' that the remaining portion is able to resist the required loads.

See Review Issue 8 (Reference 9).

Cygna noted the following during the review of the calculation for support type CSM 37b (a cantilever support)

(1) The anchor bolt was not checked for bending l

(Reference 18). In the first part of the calculation, the bending moment induced into the anchor bolt due to the rotation of the main member was calculated. A finite Texas Utilities Electric Comanche Peak Steam Electric Station

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8/19/88 Revision 4 Page 55 CONDUIT SUPPORTS Review Issues List rotation was calculated at the support fixed end using the formula 0 = T/GJ. The fixed end of a cantilever has no rotation (Reference 19). Ebasco revised this calculation (Reference 21).

(2) Ebasco did not reduce the allowable tensile load for the anchor bolt due to the presence of shear, as required by the AISC Specifications. Ebasco revised the calculations to include the reduction (Reference 21).

(3) Ebasco had not considered the OBE case as one of the design loads. Ebasco revised the calculation to consider the OBE !oad case (Reference 21).

Cygna reviewed the final Ebasco calculations which addressed these concerns and found them acceptable (Reference 22).

C. The maximum permissible loads on the outrigger Hilti Kwik bolt (HKB) will be used to determine whether, at the minimum '

credible separation distance from an adjacent HKB, the currently calculated capacity of the adjacent bolts would be affected. Calculations were performed to evaluate anchor adequacy, assuming that the distance between the adjacent HKB or Richmond Insert and the outrigger HKB is 21/2". The calculations showed that, even when the outrigger HKBs are loaded to their maximum capacity, the decrease in capacity for the proximate HKB is at most 4% (Reference 11) This conclusion was drawn assuming the adjacent HKB is 1/2" in diameter, with minimum embedment length. Ebasco concluded that there is generally no decrease in capacity. The evaluation of anchorage separation violation is based on Reference 12, which is applicable to both units.

After reviewing Ebasco's calculations, Cygna commented that, according to the requirements of the Hilti manual used in the original design, a mmimum distance of 10d (or 3-1/8" between the 3/8" bolts on the header and the 1/4" bolts in the outriggers) must be maintained in order to use the full design values. If the bolts in question were separated by the 2-1/2",

the reduction in design values would be 20%, rather than the maximum reduction of the 4% calculated by Ebasco.

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8/19/88 Revision 4 Page 56 CONDUIT SUPPORTS Review Issues List In addition to the bolt proximity violations within the support, Cygna was also concerned that spacing violations between supports also existed. In the Cygna walkdown effort, two pairs of supports (C12G050871/C12G050881 and C120505087-2/C12G05088-2) were closely spaced such that the outriggers of one support were located between those of another. The minimum spacing between the outrigger Hiltis was approximately 13/4". This results in a reduction of 30%

of the design allowables for the outrigger Hiltis.

Ebasco revised the calculations to incorporate the requirements of DBD-CS-15 in the anchor bolt design verification effort (Reference 16) Cygna reviewed Ebasco's revised calculations and accepted the methodology based on conformance with DBD-CS-15.

D. During the ISO verification process all supports will be evaluated to the requirements of Reference 13 and Appendix 3 of Reference 5 for the impact on support capacities of -

substituting of Richmond Inserts for HKBs per Reference 13 and Appendix 3 of Reference 5. The spacing between HKBs and Richmond Inserts will be considered. Generic, modified, and individually engineered supports will be evaluated for their as built conditions.

E. Cygna reviewed Ebasco's EZHANG computer program manual to determine the adequacy of the base plate and weld l

evaluations. Cygna also reviewed the verification calculations which compared EZHANG and STRUDL methodologies used to calculate conduit support frequencies and member stresses (References 17 and 18) Cygna found the comparison between the EZHANG and STRUDL analyses to be within reasonable i tolerances.

l Cygna asked Ebasco if a 1/16" gap was allowed under four bolt baseplates and if a study was conducted to determine the effect of such a gap on the resultant tensile loads in the

! concrete anchors (Reference 25) TU Electric responded that i a DCA was issued which allowed the installation of finger i

plates under cable tray support base angles when the gap under I the base angle was greater than 1/16". However, no such DCA i existed for the conduit design verification program. For the Texas Utilities Electric Comanche Peak Steam Electric Station

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Status: A. Closed.

B. Closed C. Closed D. Closed E. Closed.

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11. Lonpitudinal Loads on Transverse Suonorts

References:

L Communications Report between E. Irish (Unistrut) and J. Russ (Cygna) dated July 25, 1984

2. Communications Report between R. Kissinger and S. hicBee (TU Electric); R. hiiller (CCL); and D. Leong et al (Cygna),

dated April 9,1985

3. Deleted
4. Ebasco Specification SAG.CPIO,"Unit 1 Design Criteria for Seismic Category I Electrical Conduit Systems", Revision 7
5. CCL Report No. A-699-85, "Conduit Clamp Test Report, Phase I", dated December 17, 1985
6. CCL Report No. A 702-86, "Conduit Clamp Test Report, Phase II", dated April 7,1986 .
7. J. Richards (Cygna) letter to W. G. Counsil (TU Electric),

"Conduit Support Review Questions", 84056.110, dated hfarch 18, 1987

8. Transcripts of Conduit Supports, Cable Trays, Pipe Stress and Pipe Supports Design Verification hiceting between TU Electric, Cygna, Stone and Webster, Impell and Ebasco, dated hf arch 24 and 25,1987
9. Communications Report between S. Harrison, L Natzic (TU Electric) and D. Leong, J. Russ (Cygna) dated October 1,1987, 9.25 a.m.
10. Communications Report between HS. Yu (Ebasco) and D. Leong (Cygna), dated January 28,1988, 4:45 p.m.
11. Communications Report between HS. Yu et al (Ebasco); and D.

1.cong (Cygna), dated February 3,1988,1000 a.m.

12. Communications Report between S. Harrison (TU Electric) and l

D. Leong (Cygna), dated February 10,1988, 3D0 p.m.

l Texas Utilities Electric

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Summary: Some transverse supports have the same order of longitudinal stiffness al long cantilever multi-directional supports. Since conduit clamps provide restraint in three directions, longitudinal loads, which were not considered in the design, may be imparted to the supports.

Additionally, the displacements due to torsion of longitudinal support beam members may induce some longitudinal loads into transverse supports.

Response: In Unit 1, all transverse conduit supports will either be replaced or modified to a multidirectional type support. All generic supports will be design verified as multi-directional supports.

Section 2.0 of Reference 4 stipulates that all conduit supports shall be multi-directional. In Unit 1, the original governing design document (Gibbs & Hill Drawing 2323-S-0910 package) had permitted the use of transverse supports, i.e., supports intended to restrain in two directions only. These supports were characterized by clamp details utilizing P 2558 clamps with possible irregular gaps between the clamp and the conduit, which were not intended to provide

  • longitudinal restraint to conduit motion. In the original S-0910 drawing package, the supports are designated as the CHT and CST series of supports. Under current design verification requireinents, such supports will be converted to mu ti directional suprort or will be shown to function adequately as multi-directionst supports in their present configuration. The ability of a transverse support to function as a multi-directional support will be confirmed through the application of test results (References 5 and 6) Additionally, Ebasco may choose to demonstrate that a particular support is not required.

The support will then be removed.

Cygna asked Ebasco (Reference 7) if the testing program considered (References 5 and 6) clamps that were installed with irregular gaps between the clamp and conduit. Ebasco indicated that clamps with gaps were not part of the testing program. However, where required, these clamps and their supports will be upgraded to multi-directional supports (Reference 8)

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  • Review Issues List Cygna acknowledged that generic transverse supports have been voided and that a,1 transverse supports will be deleted, uppaded or qualdled to provide three-directional restraint. TU Electne provided an example ;ist which dispositions a number of existing transverse supposts. Cygna reviewed the list and accepted the procedure which addresses transverse supports.

Status: Closed.

Texas Utilities Electric Comanche Peak Steam Electric Station

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12. Ilitti Kwik Bolt Substitutions

References:

1. J. Richards (Cygna) letter to W. G. Counsil (TU Electric),

"Conduit Support Review Questions", 84056.110, dated March 18, 1987

2. Transcripts of Conduit Supports, Cable Trays, Pipe Stress and Pipe Supports Design Venfication Meeting between TU Electric, Cygna, Stone and Webster, Impell and Ebasco, dated March 24 and 25,1987
3. TNE FVM CS433, "Design Control of Electrical Conduit Raceways for Unit 1 Installation in Unit 1 and Common Areas, Revision 2
4. Communications Report between S. liarrison et al (TU Electric); and J. Russ et al (Cygna), dated October 1, 1987, 9.25 a.m.
5. Communications Report between liS. Yu et al (Ebasco) and D.

Leong (Cygna), dated February 3,1988,1000 a.m.

6. Communications Reprt between S. liarrison (TU Electde) and D. Leong (Cygna), dated February 10,1988, 300 p.m.
7. Communications Report between S. liarrison et al (TU Electric); IIS. Yu et al (Ebasco); and D. Leong et al (Cygna),

dated March 2,1988, 9.40 a.m.

8. Communications Report between S. liairison et al (TU Electric); 11S. Yu et al (Ebasco); and D. Leong et al (Cygna),

dated April 7,1988, 9.30 a.m.

Summary: Note 4 on Gibbs & liill Drawing 2323&O910, Sheet G 4a, allows the substitution of all liitti Kwik and Super Kwik bolts with those of a larger size. A reduction in the allowables for the larger bolts may be necessary since the actual spacing may be smaller than that required. Thus, a situation may occur where the replacement bolts have a lower capacity than the bolts in the original design.

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Examples of Cygnat concern are described below: 1 o CSM 18c: 1/2" Hilti Kwik bolts at 5" spacing were used in the ,

original design. If all 1/2" bolts are substituted with '

3/4' or 1" bolts, the tensile allowable for the replacement bolts will be less than the design tensile allowable of 3012 lbs. (2750 lbs for 3/4" bolts and 2930 lbs. for 1" bolts) o CSM 42 Type III: 1" Hilti Super Kwik bolts at 7.5" spacing were used in the original design (allowable tension = 12452 lbs, allowable shear = 6884 lbs). If all 1" bolts are replaced by 11/4" bolts of equal embedment, the bolt capacity is significantly reduced (allowable tension = 6405 lbs, allowable shear = 6221 lbs).

Response: Anchonge types and sizes will be identified as part of the 100% .

walkdown of conduits and conduit supports (Reference 3). Ebasco will validate the existing anchorages by comparison to design verified generic drawings or through analysis of individual supports. This process is acceptable for accessible supports.

Cygna noted that the walkdown effort documented as-built information on the support anchon and that the ISO verification process considered anchor substitutions where required. TU Electric stated that there was a document addressing inaccessible attributes which specified worst case assumptions to be taken if as-built information was not available.

Cygna has reviewed Ebasco's "Inaccessible Attributes" procedure in conjunction with Review Issue 19. (Reference 8)

Status: Closed. The inaccessible attributes portion of this issue is addressed under Review Issue 19.

Texas Utilities Electric

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13. Substitution of Smaller Conduits on CA-Tyne Sunnorts

References:

L Communications Report between S. hicBee (TU Electric) and J. Russ (Cygna) dated hfarch 7,1985

2. Gibbs & Hill Drawing No. 2323 S-0910
3. Ebasco Specification SAG.CP10, "Ur.it 1 Design Criteria for Scismic Category I Electrical Conduit System," Revision 7
4. TNE FVhi-CS-016, "Collection of As-built Data on Selected Electrical Conduits and Supports in Unit 1 and Common Areas",

Revision 1, dated August 4,1986

5. J. Richards (Cygna) letter to W. G. Counsil (TU Electric),

Conduit Support Review Questions", 84056.110, dated hfarch 18, 1987

6. Transcripts of Conduit Supports, Cable Trays, Pipe Stress and '

Pipe Supports Design Verification hiecting between TU Electric, Cygna, Stone and Webster, Impell and Ebasco, dated hfarch 24 and 25,1987

7. Communications Report between HS. Yu et al (Ebasco) and J.

Russ (Cygna), dated July 21,1987,10.30 a.m.

8. Communications Report between S. Harrisen et al (TU Electric) and D. Leong et al (Cygna), dated October 1,1987, 9.25 a.m.
9. Communications Report between S. Harrison (TU Electric) and D. Leong (Cygna), dated February 10,1988, 300 p.m.
10. TU Electric, Generic Issues Report (GIR), "Evaluation and Resolution of Generic Technical Issues for Conduits and Conduit Supports," Revision 2 Texas Utilities Electric b Comanche Peak Steam Electric Station lilittiililililliliittilin'lilIndependent Assessment Program All Phases Job No. 84056 \TUE\S4056\23CS ISS m

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  • Review Issues List Summary: CA type supwrts are designed u:ing ZPA for large (2 2") diameter conduits whi e peak accelerations are used for small diameter conduits

(< 2") For CA type supports where capacities are tabulated on the drawings, small diameter conduits may be installed unless specifically prohibited on the drawings. Although the deadweight load of the small diameter conduits must be less than the capacity, the seismic load of the small diameter conduits may exceed the equivalent seismic load of the large diameter conduits considered in the original design.

As an example, support type CA 15 was designed for two 3" conduits with a deadweight capacity of 156 lbs. IIowever, five 11/2" conduits can be installed on a CA 15 support, giving higher seismic loads than designed for. The rigid span loads for two 3" conduits are 343 lbs.

and 109 lbs. for the vertical and horizontal directions respectively.

The flexible span loads for five 11/2" conduits are 504 lbs. and 450 lbs. for the vertical and horizontal directions respectively.

This item possibly affects support types CA-6, CA 7, CA 12, CA 14 series, and CA 16a. .

Response: There are two categories of CA type supports. One category consists of those supports using Unistrut members. The other category consists of supports constructed from structural shapes and plates. The Unistrut CA type supports are qualified by test or by analysis. Those Unistrut supports which cannot be design verified by test or analysis are being replaced. (See Issue 8.)

For the supports constructed from structural shapes and plates, Section 3.0 of Appendix 13 of the GIR (Reference 10) discusses support frequencies in the range of 12 to 16 Hz. Cygna asked how the presence of lower frequency supports affect th: DAF study, which assumed a minimum frequency of 14.45 Hz (Reference 5)

Ebasco responded that they were deleting the use of LA-spans. All supports would now be designed for the design "g" values. Cygna reviewed selected calculations to verify implementation of this commitment.

Status: Closed.

Texas Utilities Electric ,

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14. Use of CA-Tvoe Suonorts in LS Spans

References:

1. Communications Report between hi. Warner et al (TU Electric) and W. Horstman, et al (Cygna), dated February 20, 1985
2. Communications. Report between M. Warner (TU Electric) and N. Williams et at (Cygna), dated February 27, 1985
3. Communications Report between S. McBee (TU Electric) and J.

Russ (Cygna), dated March 7,1985

4. Ebasco Specification SAG.CP10, "Unit 1 Design Criteria for Seismic Category I Electrical Conduit System", Revision 7
5. TNE FVM-CS-033, "Design Control of Electrical Conduit Raceways for Unit 1 Installation in Unit 1 and Common Areas",

Revision 2

6. J. Richards (Cygna) letter to W. G. Counsil (TU Electric), '

"Conduit Support Review Questions", 84056.110, dated March 18, 1987

7. Transcripts of Conduit Supports, Cable Trays, Pipe Stress and Pipe Supports design verification Meeting between TU Electric, Cygna, Stone & Webster, Impell and Ebasco, dated March 24 anc. 25,1987
8. Ebasco Specification SAG.CP25, "Iso Verification Guidelines,"

Revision 1

9. Communications Report between IIS. Yu et al (Ebasco) and J.

Russ (Cygna), dated July 21,1987,10.30 a.m.

10. Communications Report between S. Flarrison et al (TU Electric) and J. Russ et al (Cygna), dated October 1, 1987, 9.25 a.m.

Texas Utilities Electric Comanche Peak Steam Electric Station b ' ' Independent Assessment Program All Phases s'tillnittititittiililililiitiJob No. 84056 \TUE\S4056\23CS ISS u

t 8/19/88 Revision 4 Page 66 CONDUIT SUPPORTS Review Issues List Summary: CA type supports are used to support LA spans, which are limited to a 6'-0" length. CST type and CSM type supports are used to support LS spans, which can be up to 12'0" for transverse spans and 24'-0" for longitudinal spans. In field installations, when conduits run from walls to equipment in the middle of a room, a transition is made between LA spans and LS spans. The concerns are discussed below.

For CA type supports, ZPA was used to determine the design load for larJe diameter conduits (2 2" diameter.) Since the conduits are fie:d run, CA type supports may be installed adjacent to multi directional supports. The span between the two cupports is considered to be an LA span, since the span length must not exceed that specified by the design of the CA type support. The rigidity of the span can no longer be assumed, due to the flexibility of the multidirectional support and the effect of the flexible spans past the multi directional support. Peak acceleration should then be used to determine the design load for that span. .

There is evidence that decreased support capacity is considered for the fire protected supports (see TU Electric Instruction CP EI-4.0-49), since support capacities are given for both LA spans and LS spans. For unprotected lines, there is no indication that this was considered.

Response: Ebasco has eliminated the use of LA spans in the S-0910 package.

As a result, all support capacities are currently based on cesign "g" values. Cygna concurs with this final position and verified that all current analyses reflect this requirement.

Status: Closed.

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15. Stresses in Cabb Trays Due to Attached Conduit Succorts

References:

1. Deleted
2. Gibbs & liill Calculation 2323 SCS 156C, Set 1, Sheets 1011M
3. Ebasco Specification SAG.CPIO,"Unit 1 Design Criteria for Seismic Category I Electrical Conduit System," Revision 7
4. TNE-FVMCS-033, "Design Control of Electrical Conduit Raceways for Unit 1 Installation in Unit 1 and Common Areas",

Revision 2

5. Transcripts of Conduit Supports, Cable Trays, Pipe Stress and Pipe Supports Design verification Meeting between TU Electric, Cygna, Stone and Webster, Impell and Ebasco, dated March 24 anc 25,19S7
6. Communications Report between liS. Yu et al (Ebasco) and J.

Russ (Cygna), dated July 21,1987,10.30 a.m.

7. Communications Report between II.S. Yu (Ebasco) and J. Russ (Cygna), dated September 24,1987,10:45 a.m.
8. Communications Report between K. T. Wu et al (Ebasco) and B. Shakibnia et al (Cygna), dated September 25,1987, 2:30 p.m.
9. Communications Report between S. Ilarrison et al (TU Electric) and J. Russ et al (Cygna), dated October 1, 1987, 9.25 a.m.
10. Communications Report between S. liarrison et al (TU Electric); ilS. Yu et al (Ebasco); and D. Leong et al (Cygna),

dated March 2,1988, 9:40 a.m.

11. Communications Report between S. liarrison et al (TU Electric); IIS. Yu et al (Ebasco); and D. Leong et al (Cygna),

dated March 25,19SS,9:40 a.m.

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12. Communications Report between S. liarrison (TU Electric); llS.

Yu et al (Ebasco); and J. Russ et al (Cygna), dated April 13, 1988, 9.15 a.m.

13. Communications Report between S. Ilarruon et al (TU Electric); 11S. Yu et al GSasco dated April 25,1988, U0 em. ); nd D. Leong et al (Cygna),
14. Communications R(port beiween S. liarrison et al (TU Electric); liS. Yu e' al (Lbasco), ;nd D. Leong et al (Cygna),

dated April 27,1988, 315 p.m.

15. Ebasco Calculation Book SPAN 1191,"Span Verification of Conduit Support Systems for Suspended Runs" Revision 1 Summary: This item applies to CSD 16 in the Cygna review scope and to any similar details. Cable tray spans are ostensibly designed to the capacity of the tray The addition of CSD-16 to the tray rails adds -

loads above the capacity of the cable tray. Therefore, a generic stress check for the trays is not possible, and all tray spans with these conduit supports should be individually checked. Additionally, in the design of the CSD-16 supyrt, peak acceleration was used to determine ,oads due to the flexiale conduit section, and zero period acceleration (ZPA) was used to determine loads due to the ripid conduit attached to the cable tray. Since the support is attached to the flexible tray span, there will be additional amplification of input acceleration on the CSD-16 support. As a minimum, peak acceleration should be used for all conduit segments. An additional dynamic amplification factor (DAF) may be required.

Response: Cygna reviewed the Ebasco calculation (Reference 15) in which Detail CSD16 was evaluated. Cygna expreved concern regarding the effect of amplification of the cable tray span on the acce erations used for the evaluation of the cor.duit support detail. Ebasco stated the cable tray acceleration adequately represented the dynamic input motion for the conduits because the attached conduit lengths were designed to be rigid.

Ebasco stated that amplified response spectra would not be generated for conduits at points of attachment to trays. This was because the ZPA magnitudes at these points would not be greater than 1.5 times Texas Utilities Electric Comanche Peak Steam Electric Station

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Independent Assessment Program All Phases

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8/19/88 Revision 4 Fage 69 CONDUIT SUPPORTS mi Review Issues List peak acceleration of the floor response spectra which were ceing used in the evaluation of Detail CSD-16 (References 3 and 12).

Ebasco stated that the frequency of the conduit system attached to cable tray is in the rigid range and, therefore, the use of 1.5. times peak acceleration was conservative. Cygna agreed with Ebasco's conclusions (Reference 12). Ebasco will revise the CSD-16 drawing sheet to indicate the maximum conduit section lengt.m as qualified in the generic design verification calculation.

For all installed conduit supports attached to cable trays, as-built drawings will be generated according to the w.2kdown procedures.

These as-built drawings will be compared to the generic CSD-16 cetail. Those supports that do not conform to the generic detail, they will be individually qualified. SAG.CP25 has been revised and now specifies that a frequency check, stress check and connection check will be required for t',ese cases which exceed the limits of deneric detail.

Cygna accepted Ebasco's methodology and closed the issue. ,

Status: Closed.

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16. Increates in Allowable Soan Lengths

References:

L Communications Report between P. Huang (Gibbs & Hill) and D.

Leong and J. Russ (Cygna), dated December 27,1984

. 2. Gibbs & Hill Calculation 2323-SCS-189C, Set 1, Sheets 15-24

3. Communications Report between R. Kissinger and S. McBee (TU Electric); P. Huang (Gibbs & Hill); R. Miller and R. Yow (CCL); and D. Leong and J. Russ (Cygna), dated April 10, 1985
4. Ebasco Specification SAG.CP20, "Unit 1, Technical Guidelines for System Analysis of Conduit Span Configurations",

Revision 4

5. Transcripts of Conduit Supports, Cable Trays, Pipe Stress and Pipe Supports Design Verification Meeting between TU Electric, Cygna, Stone and Webster, Impell and Ebasco, dated March 24 and 25,1987
6. Communications Report between H.S. Yu et al (Ebasco) and J.

Russ (Cygna), dated July 21,1987,10.30 a.m.

7. Communications Report between C. Y. Chiou (Ebasco) and D.

Leong and J. Russ (Cygna), dated September 2,1987,11:45 a.m.

8. Cominunications Report between S. Harrison et al (TU Electric) and J. Russ et al (Cygna), dated October 1, 1987, 9 25 a.m.

Summary: In the revised Gibbs & Hill Drawing 2323-S-0910 package, LA span lengths were increased by a ratio of the refined to the unrefined spectra. Gibbs & Hill provided a calculation to show that the above l changes are correct with respect to the spectral ratios and that rigid spans remain rigid (diameters > 2"). This is adequate for support designs, since support loads are proportional to span lengths.

However, an evaluation of the conduit stress is required, since l conduit bending stress . proportional to the square of the span l length.

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8/19/88 Revision 4 Page 71 CONDUIT SUPPORTS Review Issues List Response: In the original S-0910 package, the LA span lengths, even when based upon the refined spectra, were all equal to or less than the LS span lengths. The LA span lengths for large conduits were rigid and the small conduits were flexible. The LS spans were flexible for all conduit sizes. The conduit bending stresses consequently were evaluated using LS spans. The evaluation for LA spans was not required since they are shorter than LS spans (Reference 5).

Further, LA spans have since been removed from the S-0910 package. ,

All spans are now considered to be LS spans.

Reference 4 provides guidelines for the system analysis of conduit spans. Conduit stresses have been evaluated following guidelines in Section 5.0 of Reference 4 for seismic and dead loads. The span drawings in the S-0910 package will be revised (Reference 7)-

Status: Closed.

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17. Substitution of Next Heavier Structural Member

References:

L Ebasco Specification SAG.CP10,"Unit 1 Design Criteria for Seismic Category I Electrical Conduit System, "Revision 7

2. TNE-FVM-CS-033, "Design Control of Electrical Conduit Raceways for Unit i Installation in Unit 1 and Common Areas, "Revision 2
3. Communications Report between H.S. Yu (Ebasco) and B. Shakibnia (Cygna), dated August 14,1987,1100 a.m.
4. Communications Report between C. A. Liu (Ebasco) and B. Shakibnia and J. Russ (Cygna), dated September 23,1c17, 1000 a.m.
5. Communications Report between H. S. Yu (Ebasco) and B. Shakibnia et al (Cygna), dated September 24,1987,1000 a.m.
6. Communications Report between H. S. Yu (Ebasco) and B. Shakibnia (Cygna), dated September 25,1987,1145 a.m.
7. Communications Report between H. S. Yu et al (Ebasco) and B.

Shakibnia et al (Cygna), dated September 25,1987, 2:30 p.m.

8. Communications Report between H. S. Yu et al (Ebasco); S.

Harrison et al (TU Electric); and D. Leong et al (Cygna), dated l

March 2,1988, 9.40 a.m.

9. Communications Report between H. S. Yu et al (Ebasco); S.

Harrison (TU Electric); and J. Russ et al (Cygna), dated April 13,1988, 915 a.m.

I

10. Ebasco Calculation SUPT-0247, "Substitution of the Next Heavier Structural Member," Revision 0
11. Ebasco Calculation SPAN 1189, "Substitution of the Next Heavier Structural Member," Revision 1 1

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8/19/88 Revision 4 Page 73 CONDUIT SUPPORTS Review Issues List Summary: This item refers to Note 5 on Gibbs & Hill Drawing 2323-S-0910, Sheet G-la. Most supports are designed to the allowable load limits for the Hilti Kwik bolts. Since support self weight has not been properly considered in some designs (see Review Issue 7), Hilti Kwik bolts may be overstressed m, generic designs using structural steel.

I Response: All conduit supports ate being as-built as part )f a complete walkdown of the conduit system (Reference 2) Supports with heavier structural members than indicated on the S-0910 drawing sheet will be ncted, except for tube steel sections with cap plates where the thickness of the member cannot be determined. All supports, except tube steel supports, will be verified against the actual installed configurations. A generic study to assess how the S-0910 package generic support capacities are influenced by the substitution of heavier tube steel sections has been performed. The study considered two methods of modeling the weight distribution of a tube steel member and examined how these modeling assumptions affected the seismic response of the support. A description of the modeling '

approach follows-(1) During the design verification of the S-0910 package, the self-weight excitation of the su oort was assumed to be conservatively enveloped by the sum of the support weight and the conduit weight and accelerating the tot:J weight at the design "g" values of the conduit system (Reference 1); and (2) To more accurately consider the actual member weight distribution, the true self weight excitation of the member is calculated separately from the conduit load.

The frequencies of the supports were computed with the increased mass and stiffness of the substituted members and the stresses in the support were determined. It was found that many generic supports had reduced capacity. For those cases of reduced capacity, the conservatism in the analysis was removed as described below-(1) The conduit system frequency, with the increased support mass and stiffness, was determined by refining the system model.

The original model consisted of the mass of the conduit on a support spring. The system frequency was determined by l combining the frequency of the conduit and the support. The Texas Utilities Electric Comanche Peak Steam Electric Station All Phases I[

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8/19/88 Revision 4 Page 74 CONDUIT SUPPORTS Review Issues Lisi revised model consisted of the conduit mass on the spring representing the conduit stiffness in series with the mass of the support on the spring representing the support stiffness.

The system frequency calculated from the revised model was compared to the system frequency of the original model to verify that the revised system frequency is equal to or greater than the minimum rec utred frequency (Reference 10). A higher system frequency wou d result in equal or lower seismic responses. The resulting load capacity of the support with the substituted member wenld most probably be equal to or greater than the load capacity for the original support configuration.

(2) If the resulting load capacity is reduced with the substituted member, the original system analysis results would be reviewed to determine the acceleration values at the support locations, which would then be compared to the design "g" values in Reference 1 (See Review Issue 2).

(3) Stress analysis of the support member, welding, anchorages and ,

other components would be performed to determine stress levels.

The generic study for tube steel member substitution is contained in Ebasco Calculation SUPT-0247 (Reference 10). Cygna noted that the change in stress was not linearly proportional to the change in member weight plus conduit weight (Reference 4); therefore, Ebasco's method to determine the change in stress was not accurate. Ebasco agreed with Cygna's contention; however, they maintained that the method used to determine he stress ratios and check them against the original interaction ratio was conservative. Ebasco provided a demonstration of this conservatism, which was reviewed and accepted by Cygna (Reference 5).

For the disposition of those supports which could not be generically qualified for the member substitution, Ebasco stated that SAG.CP25 would be revised to specify the required limitations. Support CSM-18f (Type 17d only) was the only support which did not meet the original design capacity with the substituted member. A reduction of support capacity equal to 40% of the increased member weight (after substitution) was required for this support.

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8/19/88 Revision 4 Page 75 CONDUIT SUPPORTS Review Issues List Ebasco responded to Cygna's questions pertaining to calculations SUPT-0247, and SPAN-1189 (References 4, 5, 6,10 and 11) ir calculation SPAN 1201, which Cygna reviewed and accepted (Reference 9). Ebasco also revised SAG-CP25 to reflect the revised requirements.

Status: Closed.

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18. Clamo Usage

References:

1. N.H. Williams (Cygna) letter to J.B. George (TU Electric),

"Cable Tray and Conduit Support Review Questions" 84056.015, dated August 6,1984, question A4

2. N.H. Williams (Cygna) letter to J.B. George (TU Electric),

"Conduit Support Walkdown Questions" 84056.020, dated August 13, 1984, question 3

3. N.H. Williams (Cygna) letter to W.G. Counsil (TU Electric),

"Cable Tray / Conduit Support Review Questions," 84056.094, dated October 30, 1985

4. Communications Report between E. Irish (Unistrut) and J. Russ (Cygna) dated July 25, 1984
5. Communications Report between T. Keiss et al (TU Electric),

B. Bhujang et al (Gibbs & Hill); and W. Horstman et al ,

(Cygna), dated October 9,1984

6. Communications Report between R. hiilier and R. Yow (CCL); E.

Bezkor and P. Huang (Gibbs & Hill); C. hiortgat (TERA); R.

Kissing:r and S. hicBee (TU Electric); and N. Williams and J.

Russ (Cygna), dated hfarch 29, 1985

7. Gibbs & Hill Calculation 2323-SCS-1005, Set 1, Sheets 9-13, regarding clamp reaming
8. Gibbs & Hill Calculation 2323-SCS-1005, Set 1, Sheets 7-8, regarding clamp distortion
9. Generic Issues Report (GIR), "Evaluation and Resolution i of Generic Technical Issues For Conduits and Conduit 1 Supports", Revision 2
10. Deleted
11. CCL Report No. A-699-85, "Conduit Clamp Test Report, Phase I", dated December 17, 1985 l

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12. CCL Report No. A-702-86, "Conduit Clamp Test Report, Phase l II", dated April 7,1986
13. Ebasco Specification SAG.CP10, "Unit 1 Design Criteria for Seismic Category I Electrical Conduit System", Revision 7
14. J. Richards (Cygna) letter to W. O. Counsil (TU Electric),

"Conduit Support Review Questions", 84056.110, dated March 18, 1987

15. Transcripts of Conduit Supports, Cable Trays, Pipe Stress and Pipe Supports Design Verification Meeting between TU Electric, Cygna, SWEC, Impell, and Ebasco, dated March 24 and 25,1987
16. Transcripts of Conduit and Conduit Supports Design Verification Meeting between TU Electric, Cygna, Ebasco, Impell, and SWEC held at the CPSES site, April 21, 1987
17. Communications Reports between S. Harrison and L Natzic (TU .

Electric); T. Kuo (Ebasco); and B. Shakibnia et al (Cygna),

dated August 31,1987, 9:30 and 1000 a.m.

l 18. Communication Report between CY. Chiou (Ebasco) and B.

Atalay et al (Cygna), dated September 1,1987, X) a.m.

19. Communications Report between CY. Chiou and T. Kuo (Ebasco); and B. Shakibnia et al (Cygna), dated September 2,1987, 2:10 p.m.
20. Communications Report between C Y. Chiou (Ebasco); D. Leong and B. Atalay (C,yna); and F. Thomas (CCL), dated September l

3,1987,10:15 a.m.

21. Communications Report between C Y. Chiou (Ebasco) and D. Leong (Cygna), dated September 3,1987, 2:45 p.m.

l 22. Communications Report between C Y. Chiou (Ebasco) and B.

l Atalay (Cygra), dated September 4,1987,100 p.m.

23. Communications Report between L Natzic (TU Electric) and B.

Atalay and D. Leong (Cygna), dated September 4,1987, 2:15 p.m.

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24. Ebasco Specification SAG-CP21, "Unit 1, Technical Guidelines for Thermal Analysis of Seismic Category I Electrical Conduit System," Revision 4
25. ANCf Document No. A-000189, ' Test Procedure for Conduit Dynamic Tests," Revision 0, dated April 1987
26. Ebasco Specification SAG CP26, "Specification for Dynamic Test of Conduit Clamp for CPSES Unit No.1 and 2," Revision 1, dated April 10, 1987
27. Communications Report between S. Harrison et al (TU Electric) and J. Russ et al (Cygna), dated October 1,1987, 9.25 a.m,
28. Communications Report between H. S. Yu (Ebasco) and B.

Atalay et al (Cygna), dated January 25,1988,11:50 a.m.

29. Communications Report between H. S. Yu et al (Ebasco) and '

B. Atalay et al (Cygna), dated January 29,1988, 4.00 p.m.

30. Communications Report between H. S. Yu et al (Ebasco) and D. Leong et al Cygna), dated February 5,1988,1:30 p.m.
31. Communications Report between S. Harrison et al (TU Electric);

H. S. Yu et al (Ebasco); and D. Leong et al (Cygna), dated April 7,1988,10.10 a.m.

32. Communications Report between S. Harrison (TU Electric);

H. S. Yu et al (Ebasco); and J. Russ et al (Cygna), dated April 14,1988,130 p.m.

33. Communications Report between S. Harrison et al (TU Electric);

and H. S. Yu et al (Ebasco); and D. Leong et al (Cygna), dated April 25,1988, 2.00 p.m.

34. Communications Report between S. Harrison et al (TU Electric);

F. Thomas (CCL); and D. Leong et al (Cygna), dated April 27, 1988,1015 a.m.

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1 8/19/88 Revision 4 Page 79 CONDUIT SUPPORTS Review Issues List Summary: A. Reaming of Bolt Holes In the following two Gibbs & Hill designs in Cygna's review scope, P2558 clamps may be reamed to accommodate larger bolts. As a result, the minimum edge distance requirements are violated.

For CA-Sa supports, clamps for small diameter conduits (< 2")

must be teamed to accommodate 3/8" Hilti Kwik talts. The washers for 3/8" Hilti Kwik bolts will not fit properly on the clamps. The washer is an integral part of the bolt, and justification for its omission, alteration, or distortion during installation is required.

For the IN-CSht 15a support, clamps for the 5" diameter flexible conduit are :eamed to accommodate 1/2" Nelson studs.

In response to Reference 1, TU Electric /Gibbs & Hil! provided Reference 6 to justify teaming of clamps for conduits larger than 2" in diameter. This calculation addresses the clamps for the IN-CSh!-15a support, but does not address the clamps for the small diameter conduits for the CA-Sa supports.

B. C-708-S Clamps C-703-S clamps for conduits can be modified by cutting off the end portion of the clamp ears. This modification removes two of the four bolt holes from the clamp. Justification for this modification is required. Also see Review Issue 9 for discussion of clamp allowables.

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8/19/88 Revision 4 Page 80 CONDUIT SUPPORTS Review Issues List C. Clamp Distortion In the Cygna walkdown, clamp distortion was noted for the following supposts:

Suonort ID Suocort Tvoe C12G03528-8 CSM-18f C12002935-4 CA-5a C12G03126-18 CSM-42 C12G02851-6 CA-Sa In response to Reference 1, TU Electric /Gibbs & Hill provided Reference 8 to justify c! amp distortion.

D. Clamp Tests This issue arose during Cygna's audit of the Canduit Corrective Action Program. A discussion of this issue appears in the Response Section belosv.

E. Clamp Factor of Safety

! This issue arose during Cygna's audit of the Conduit Corrective Action Program. A discussion of this issue appears in the l

Response Section below.

l Response: The clamp test program performed by CCL (References 11 and

12) considered oversized holes, edge distance, bolt type and size, washer omission and distortion, and distortion of clamps.

The clamp allowables used in the design verification effort are based on test resul:s and are specified in Tables 1.1 to 1.9 in Reference 13. The CCL Phase I clamp tests were performed to develop the methodology and scope of the Phase II tests.

Additionally, the Phase II verified clamp stiffness values which t were generated analytically by CCL using the EZHANG program (Reference 17)

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8/19/88 Revision 4 Page 81 CONDUIT SUPPORTS l Review Issues List l A. Reaming of Bolt Holes l

1. The Phase I Report discussed erection tolerances for_ the ,

clamps. Although procedure ECP-19 did not specify the l erection tolerances, Ebasen indicated a plus or minus 1/8" tolerance was specif ed in CSD series S-0910 drawings.

(Reference 15).

2. Table 5.1 of the Phase I Report provided capacities for three different clamp sizes for three different bolt sizes.

Several clamps showed a decrease in capacity with increasing bolt size. Ebasco indicated that the decrease in clamp capacity with increasing bolt size was due to the installation tolerances between nut and clamp radius.

Therefore, the clamp allowables specified in design criteria were in accordance with bolt size. The bolt size will be identified during the conduit support walkdown (Reference 15).

B. C-708-S Clamps All C-708-S clamps for 4" diameter or larger conduits are acceptable provided the span does not exceed 6'-3" (Reference 9). If the span is greater, the clamp will be qualified by performing a dynamic analysis on a system basis or it will be replaced by a qualified clamp. The presence of the C-708-S clamps on conduits 4" and larger has been identified during the conduit support walkdown. There are a total of 407 such clamps. Every one of these cases will be walked down again to measure the actual span length.

During the conduit support walkdovin effort, the clamp types were determined by measuring the width of the clamps. For conduit diameters up to and including 3", the width of C-708-S clamp is 2" and for conduit diameters greater than 3", the width is 2-1/2". The width of a P-2558 clamp is 1-5/8" (Reference 15).

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Review Issues List C. Clamp Distortion Clamp distortion was considered in the clamp tests. The bolt spacing for small clamps (Clamps for conduits 1-1/2" diameter and smaller) were varied by i 1/4" in Phase I (Reference 11) and by -1/8" in the Phase II tests. Cygna asked why +1/8" bolt spacing variation was not considered in the Phase II, especially since conclusion 8 on oage 4 of Reference 12 implies smaller allowable vertical clamp loads as a result of larger bolt spacing. CCL responded that clamps had large vertical capacities and hence, qualification in the vertical direction was not a problem. Additionally, conclusion 8 did not pertain to the effect of the design clamp distortion from misalignment due to field conditions, bu: merely addressed the effect of the design bolt spacing on undistorted clamps (Reference 20)

CCL added that C-708N-U and C-708-U clamps were not tested in the Phase II. The Phase I tests demonstrated that these clamps were at least as strong as P2558 clamps. Hence, the SAG.CP10 clamp allowables tables are based on bolt diameter in lieu of clamp types (C-708N U, C 708-U or P-2558)

D. Clamp Tests

1. Failure Criteria In the CCL clamp tests, the structural failure (bolt breakage, pullout, etc.), or a limiting value of slip (1/4")

in the axia direction of the conduit constituted failure (Reference 20).

Ebasco noted that in all the tests that form the basis of the clamp allowables, failure was not observed (Reference 20).

2. Minimum Number of Cycles Used in Tests In the cyclic tests of Phase II, the loads were cycled for a minimum of 813 cycles in each of the three directions.

The 813 cycle count was based on the assumption that the clamps respond to six seismic events lasting for 10.24 Texas Utilities Electric Comanche Peak Steam Electric Station

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8/19/88 Revision 4 Page 83 CONDUIT SUPPORTS Review Issues List seconds each and to the ma:imum support / conduit frequency of 13.23 Hz at the peak of the response spectrum.

Cygna asked if it was feasible that lower design loads applied over a greater number of cycles could be more critical than the tested cases (Reference 14).

Ebasco responded that bcsed on the Standard Review Plan only 200 cycles of strong motion input were required in tests, which is well below the minimum of 813 cycles used in the cyclic test (Reference 20).

3. Method of Data Interpretation Cygna asked Ebasco/CCL for a clarification on how the test results were interpreted to obtain the clamp allowables (Reference 20).

CCL said that out of the number of samples tested for a particular clamp and conduit configuration, the minimum envelope of the three highest test samples were picked as the allowables in the cyclic test (Reference 20)

4. In the Phase II Report, some of the results reported were for test configurations which were not tested in Phase II (Reference 22). Ebasco/CCL noted that some of the results reported in Reference 12 were taken from the Phase I tests (Reference 29)

E. Clamp Factor of Safety The ultimate static capacities from the Phase I were divided by a factor of safety to arrive at the target loads used in the l cyclic tests of the Phase II. References 11 and 12 did not j state the basis for these factors of safety. Additionally, the factors of safety used to arrive at the final clamp allowables were not clearly established.

Ebasco said that the term "factor of safety" as described in l

References 11 and 12 was a misnomer. The quantities termed as "factors of safety" were merely values that the ultimate l

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8/19/88 Revision 4 Page 84 CONDUIT SUPPORTS Review Issues List static capacities were divided by to arrive at the target loads.

These values were chosen arbitrarily (Reference 20).

Ebasco added that no consideration was given to the phenomenon of factor of safety in developing the clamp allowables since the allowables were based on three-dimensional, cyclic proof tests. Therefore, it was not necessary to demonstrate any factor of safety over the test results (Reference 33).

Cygna accepted Ebasco's position on this issue.

Status: A. Closed.

B. Closed.

C. Closed.

D. Closed.

E. Closed.

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19. Documentation Deviations Between Insoection Reoorts. CMCs and IN-FP Drawines

References:

1. N.H. Williams (Cygna) letter to W.G. Counsil (TU Electric),

"Cable Tray / Conduit Support Review Questions" 84056.094, dated October 30, 1985

2. Communications Report between P. Patel (TU Electric) and D.

Leong and J. Russ (Cygna), dated February 18, 1985

3. Deleted
4. Deleted
5. J. Richards (Cygna) letter to W.G. Counsil (TU Electric),

"Conduit Support Review Questions," 84056.110, dated March 18, 1987

6. Transcripts of Conduit and Conduit Supports Design Verification Meeting between TU Electric, Cygna, Ebasco, Impell and SWEC ,

held at the CPSES site, April 21, 1987

7. TU Electric SDAR CP-85-42, 'Thermolag," dated September 24, 1985
8. Communications Report between HS. Yu et al (Ebasco) and J. Russ (Cygna), dated July 20,1987, 9.50 a.m.
9. Communications Report between S. Harrison (TU Electric) and J. Russ (Cygna), dated August 31,1987,1045 a.m.
10. Communications Report between R. Beam et al (Ebasco) and J. Russ (Cygna), dated September 1,1987, 9D0 a.m.
11. Communications Report between S. Harrison et al (TU Electric) and J. Russ et al (Cygna), dated October 1,1987, 925 a.m.
12. Communications Report between HS. Yu et al (Ebasco); and D. Leong (Cygna), dated February 3,1988,1000 a.m.

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13. Communications Report between HS. Yu et al (Ebasco);

S. Harrison et al (TU Electric); and D. Leong et al (Cygna),

dated April 13,1988, 915 a.m.

14. Communications Report between HS. Yu et al (Ebasco);

S. Harrison et al (TU Electric); and D. Leong et al (Cygna),

dated April 25,1988,100 p.m.

15. Communications Report between HS. Yu et al (Ebasco);

S. Harrison et al (TU Electric); and D. Leong et al (Cygna),

dated April 26,1988, 3D0 p.m.

16. Communications Report between HS. Yu et al (Ebasco);

S. Harrison et al (TU Electric); and D. Leong et al (Cygna),

dated April 27,1988, 3:15 p.m.

17. Ebasco Specification SAG-CP25, ' Technical Guidelines for Seismic Category I Electrical Conduit Isometric Validation,"

Revision 2 Summary: A. For each conduit line, an inspection is performed and documented on an inspection report (IR). All CMCs and applicable IN-FP drawings should be reflected on the IR.

Examples of Cygnn's concerns are discussed below:

1. Line C11003395, IRME-18120F, Support 1: On the IR, the support is listed as CSM 18f, Revision 4. On CMC 62903, the support is listed as CSM-18b, Revision 14. Based on the CMC information, the IR is in error.
2. Line C12G05087, IRME-16817F, Support -4: On the IR, the support is listed as CSM-18c. Revision 13. On CMC 62905, Revision 0, the support is listed as Revision 9. On CMC 62905, Revision 1, the support is listed as Revision
12. , Five such dixrepancies occur for supports in Cygna's review scope.
3. Line C12004695, IRME-16089F, IN FP-216 and IN FP-226:

There are discrepancies between the IR and both IN FP drawings for support types CA la and CA 2a. There is no structural difference in the supports, but a documentation Texas Utilities Electric Comanche Peak Steam Electric Station Independent Assessment Program All Phases IIllillililllililllIllililIlliJob No. 84056 \TUE\84056\23CS-ISS

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8/19/88 Revision 4 Page 87 CONDUIT SUPPORTS Review Inues List inconsistency exists. Nine such discrepancies occur for supports in Cygna's review scope.

4. All applicable CMCs and their revision numbers should be listed on the inspection reports. In Cygna's review scope, three CMCs were not listed on the appropriate IR. CMCs 59701,69387, and 68272 should be listed on IRME-20073F.

Revision numbers were not provided for the following five CMCs: On IRME-18120F, CMCs 67042 and 62903; on IRME-20143F, CMCs 68276 and 75090; and on IRME-17398F, CMC 68438.

B. Additionally, the Cygna walkdown identified deviations between the final inspection reports and installed configurations for two conduit lines.

1. Conduit line C12002935 appears to have been rerouted.

The final inspection report IRME-16236F lists four supports on the line. There are three supports on the '

line in the field. Support C12002935-3 has been removed, and support C12002935 2 has been re marked C12002935-5.

An updated IR was not found.

l 2. Support IN-CSM 15b is not listed on the inspection report l IRME 14684F. It is present in the field.

, Response: An investigation of the documentation discrepancies identified in the l

background of this issue was performed by Gibbs & Hill to assess the j effects and possible causes of these discrepancies. The results of the investigation for each item are described below. The item numbers l correspond to the Cygna concerns listed above.

A. Errors in Inspection Reports-l L This is an isolated inconsistency and may not be classified as a discrepancy. The as-built configuration is an L shaped support utilizing a tube member heavier than CSM-18f, i.e., TS 4x4x375. The IRME does refer to a CMC on this configuration.

2. The IRME included the latest revision of CSM 18c at the time, which was Revision 13, while actual CMCs had l

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.r 8-8/19/88 Revision 4 Page 88 CONDUIT SUPPORTS Review Issues List referred to earlier revisions. This is presently considered to be a random occurrence pending assessment of other conduit runs.

3. Since no functional structural differences exist for support types CA la and CA-2a, this documentation difference is not significant.
4. This appears to be an isolated, random situation, pending essessment of other conduit runs. Most of the CMCs given above were Revision 0; therefore, the revision number was inadvertently left out.

B. Installed Deviations With Inspection Reports-

1. This is an isolated case where the IRME was not updated after the line was modified.
2. The original IRME did include an item referred to as .

CSM 15b, without the "IN." prefix. Immediately afterwards, the IRME was updated by adding the prefix "IN " to the item.

Subsequent to the Gibbs & Hill effort, Ebasco proposed to perform a sampling evaluation of installed conduit systems. Cygna raised questions which pertained to the documentation discrepancies and their effect on the conduit sample selection, since the inspection reports were used to choose the sample. (Reference 5) <

l Subsequently, the sample evaluation was upgraded to a 100% walkdown and design verification of the Unit 1 conduit systems. Ebasco believed that Cygna's questions and concerns were no longer applicable, since sampling will not be used in the current program.

The as-built data from the walkdown will replace the existing documentation for the design validation process. Hence, the discrepancies in the Unit 1 documentation ha.<e no impact on the l

l qualification process.

Ebasco added that the only hardware information from the ins .stion reports that would be used in the design verification would pertain to welds only. No other information from the inspection reports would be used in the design verification effort. The adequacy of the weld 1

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l documentation is covered under the QA/QOC review. Cygna reviewed and discussed (Reference 13) Ebasco's "Inaccessible Attribute" procedures for the other commodities (Reference 17) with respect to the existing documentation. The procedure was reasonable for each commodity, and Cygna accepted Ebasco's treatment of inaccessible attributes.

Status: A. Closed.

B. Closed.

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- 20. Nelson Studs

References:

1. Communications Report between P. Huang and R. Sanders (Gibbs & Hill) and J. Russ (Cygna), dated August 7,1984
2. Gibbs & Hill Calculation 2323-SCS-156C, Set 1, Sheets 131-160
3. Gibbs & Hill Calculation 2323-SCS-109C, Set 1, Sheets 164-184
4. CCL Report No. A-699-85, "Conduit Clamp Test Report, Phase I," dated December 17, 1985
5. CCL Report No. A-702-86, "Conduit Clamp Test Report, Phase II," dated April 7,1986
6. TRW Nelson Standard In-Stock Catalog,1985
7. TNE-FVM-CS-016, "Collection of As-Built Data on Selected Electrical Conduits and Supports in Unit No. I and Common ,

Areas," Revision 1, dated August 4,1986

8. Drawing No. 2323-S-0910 Package
9. Drawing No. 2323-S2-0910 Package
10. Ebasco Specifier. tion SAG.CPIO, "Unit 1 Design Criteria for Seismic Category I Electrical Conduit Systen ," Revision 7
11. Communications Report between K. T. Wu et al (Ebasco) and B.

Shakibnia et al (Cygna), dated September 25,1987, 2 30 p.m.

12. Communications Report between S. Harrison et al (TU Electric);

HS. Yu et al (Ebasco); and D. Leong et al (Cygna), dated March 2,1988, 9:40 a.m.

13. Communications Report between S. Harrison et al (TU Electric);

HS. Yu et al (Ebasco); and D. Leong et al (Cygna), dated .

March 25,1988, 9:40 a.m.

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14. Communications Report between S. Harrison (TU Electric);

HS. Yu et al (Ebasco); and D. Leong et al (Cygna), dated April 13,1988, 9.15 a.m.

15. Communications Report between S. Harrison (TU Electric);

HS. Yu et al (Ebasco); and D. Leong et al (Cygna), dated April 14,1988,130 p.m.

16. Communications Report between S. Harrison et al (TU Electric);

HS. Yu et al Ebasco; and D. Leong et al (Cygna), dated April 25,1988, 900 a.m.

17. Ebasco Calculation, "Justification of Shim Plate and Tube Steel Analysis for Clamp Attachments" Book 44, Volumes 1 and 2.

t!

18. Communications Report between S. Harrison et al (TU Electric); HS. Yu et ai (Ebasco); and J. Russ et al (Cygna).

dated April 25,1988, 9:00 a.m.

Summary: In the original conduit support design calculations, Gibbs & Hill did not check Nelson studs for conformance with vendor specifications

! and allowables. Subsequently, Gibbs & Hill supplied Cygna with Nelson stud qualification calculations to determine the adequacy of the installed stud configurations. Cygna has the following comments on the calculations provided-o Reference 3 provides an evaluation of the stud stresses. A pretensioning force was assumed to relieve applied loads to the l

' studs. The calculation did not account for the flexibility of the clamp and shim plate or relaxation of the preload.

o The allowable Nelson stud forces reported by TRW/ Nelson are based on shear applied at the weld location. In the conduit support oesigns, the studs are loaded at the clamp, which produces a moment in the stud. This additional moment was not considered in the Reference 3 calculation.

o Reference 2 (Sheets 151 through 160) provides evaluation of the i shim plate attaching the Nelson studs to the structural member.

The stress distribution assumed for the weld connecting the shim plate to the member is not realistic, as it introduces an infinite stress at the bottom of the plate. The assumption Texas Utilities Electric g[ 3 Comanche Peak Steam Electric Station Independent Assessment Program - All Phases IIll!!Illillt.IllllIllllilllllJob No. 84056 \TUE\84056\23CS-ISS l

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i 8/19/88 Revisior. 4 Page 92 CONDUIT SUPPORTS U Review Issues List affects the results of the yield line analysis performed to check the adequacy of the shim plate.

o Wcld underrun was not considered in the Reference 2 calculation. .

Response: Allowable capacities for clamps using Nelson studs have been established via testing (References 4 and 5) These tests accounted' for the flexibility of the clamp and shim plate and relaxation of the preload. . Calculated loads at the clamp have been evaluated against the allowables estab ished by test. If the allowables are not exceeded, the adequacy of the stud is assured. Otherwise, the clamp may be replaced or the conduit span may be reduced.

o In certain instances, C-708-S clamps for 4 inch diameter conduit or larger in both Units will be replaced. For other -

conduit sizes, the clamps have been qualified for the allowable conduit spans specified in References 8 and 9.

o Section 7.0 of Reference 10 specifies the stud pretension fetce and acceptable ductility ratio used in the design verification of conduit connection details. Design verification for Unit No.1 is complete, and all details are acceptable, except CSD 142, Section BB, and CSD-14c, Section AA. These will be evaluated during the ISO verification effort on a case by-case basis.

o In response to Cygna's concern pertaining to the yielding of the tube steel member under pretension load, Ebasco performed a nonlinear analysic (Reference 17) and provided Cygna with

oad versus displacement values for the node points in the vicinity of the clamp studs. Using this data Cygna calculated the slopes (f the load-displacement curve for the last three load steps used in the analysis. These slope values indicated that the load-displacement curve at or around the pretension load was not flat, meaning that small changes in applied load did not induce large or excessive changes in displacements

, (Reference 18).

i Cygna has completed the audit of calculations for a number of CSD senes details with Nelson studs and has found the design methods to be acceptable.

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8/19/88 Revision 4 Page 94 CONDUIT SUPPORTS Review Issues List 2L Conduit Fire Protection Calculation

References:

1. N.H. Williams (Cygna) letter to W.G. Counsil (TU Electric),

"Cable Tray / Conduit Support Review Questions," 84056.094, dated October 30, 1985

2. Communications Report between T. Keiss (TU Electric) and W. Horstman et al (Cygna), dated October 16, 1984
3. Communications Report between S. McBee (TU Electric) and D.

Leong (Cygna), dated April 18, 1985

4. TU Electric Instruction CP-EI-4.0 49
5. Gibbs & Hill Calculation 2323-SCS 1017, Set 2, Sheets 811
6. Gibbs & Hill Calculation 2323-SCS-152C, Set 1, Sheet 39.h
7. Gibbs & Hill Calculation for Drawing 2323-S-0910, Sheet .

IN FP 213a

8. Gibbs & Hill Calculation for Drawing 2323-S-0910, Sheet IN FP-212
9. Gibbs & Hill Calculation for Drawing 2323-S-0910, Sheet IN FP-214
10. Gibbs & Hill Calculation 2323-SCS-23?C, Set 1, Sheets 62-67 for Drawing 2323 S-0910, Sheet IN FP 226
11. TU Electric SDAR CP-85-42, 'Thermolag," dated September 24, 1985 t

! 12. TU Electric SDAR CF 85-31, "Electrical Raceway Support l System," dated August 27, 1985 l 13. Transcripts of Conduit Supports, Cable Trays, Pipe Stress and l Pipe Support Design Verification Meeting among TU Electric, I Cygna, SWEC, Impell and Ebasco, dated March 24 and 25,1987 i

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14. J. Richards (Cygna) letter to W.G. Counsil (TU Electric),

"Conduit synca Review Questions" 84056.110, dated March 18, 1987

15. Communications Report between D. Leong et al (Cygna); T. Kuo (Ebasco); and S. Harrison et al (TU Electric), dated August 31, 1987, 9:30 a.m.
16. Communications Report between R. Beam et al (Ebasco) and J.

Russ (Cygna), dated September 1,1987, 990 a.m.

17. Communications Report between S. Harrison et al (TU Electric) and J. Russ et al (Cygna), dated October 1,1987, 9.25 a.m.
18. Communications Report between S. Harrison (TU Electric) and D. Leong (Cygna), dated February 10, 1988, 3:00 p.m.

Summary: All calculations providing evaluation of fire protected conduits and -

conduit supports were obtained from Gibbs & Hill prior to the r completion of the design review for those calculations. The comments made in this review issue may have been resolved due to design review efforts.

A. All of the Gibbs & Hill fire protection calculations consider a round configuration of thermolag material around conduits.

The thermolag weight on the spans was calculated based on

this configuration. The Cygna walkdown and discussions with TU Electric indicate that a square configuration was also used in the field installations. Documentation of the specific '

1 configuration installed was not maintained. ,

! B. Reference 5 calculates the capacities of CA la supports for i various plant elevations using both LA and LS-spans. The l analysis model used in the calculation supported one conduit l and had two sets of outriggers. Reference 4 provides tables of the capacities for use in cetermining the adequacy of CA la supports with fire protection; however, the tables do not I specify that the capacities given are limited to the support configuration used in the analyses.

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8/19/88 Revision 4 l Page % l CONDUIT SUPPORTS 1 Review Issues List l C. Capacities for CA-2a supports are given in Table 24 of Reference 4. Reference 6 contains calculations which determine support capacities for CA-la and CA-2a supports with multiple conduit installations. Reference 6 states that CA la capacities should be used for CA 2a supports, since CA-2a supports are "similar to and stronger" than CA la supports. The allowable capacity for LA-spans calculated in the referenced calculation is 185 lbs. Table 24 of Reference 4 gives the allowable as 385 lbs. The tabulated capacities for CA-2a appear to be in error, when compared with the CA la capacities in Tables 25 and 26 of the same reference.

D. In the review of IN-FP calculations, Cygna has three concerns regarding detailed calculhtions used to demonstrate support adequacy.

L The IN FP drawings, generally contain information on span length, support location on the conduit run, and type of support (such as Type 17d or 17e for a CSM 18c support).

In some cases, the mounting surface will be indicated (such as ceiling. mounted or wall mounted), as well as key dimensions for a support (such as cantilever length).

Cygna has noted that orientation of the support on the mounting surface is almost never given, yet the IN FP calculations assume a configuration for the detailed analysis. Two supports in Cygna's review scope which are gualified based on such assumed configurations are

.,12G03126-1 and C12G031261L

2. Cygna has noted that some detailed calculations do not include the effects of CMCs when analyzing the supports for the effects of fire protection. Three supports in Cygna's review scope which neglect CMCs are C12G05087-4, C12G03126-2, and C11003395-2.
3. Cygna has noted that the support capacities used for the qualification of fire protected supports were taken from the drawing revisions which were current when the IN FP calculatior.s were performed, although the suppo,rts were originally installed and inspected to earlier revisions.

Justification for using these capacities was not provided.

l Four supports in Cygna's review scope which are l

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t 8/19/88 Revision 4 Page 97 CONDUIT SUPPORTS Review _Irsues List qualified to later drawing revisions are C12004695-5, c12G05087 4, C12G03126 2, and C11003395-2.

Response: A. The evaluation of conduit systems for the addition of fire protection was lequired in response to SDAR CP-85-42 and SDAR CP-85-31 (References 11 and 12, respectively)

Currentiy, Cygna understands that all fire protection material is being removed to facilitate the walkdown effort. TU Electric is also redefining the extent of fire protection to be reins'.alled All systems which are to be fire protected will be analyzed by RSM (Reference 15) Cygna reviewed the RSM instructions in SAG.CP25 and found them teceptable.

B. The capacities for support types CA la an'J CA 2a will be revised in accordance with test results. Supports of these types were as-built during the recent walkdown effort, and the impact of the revised s'ipport capacities are to be assessed.

C. See the response for Item B above. .

D. Cygna questioned the walkdown verification of IN-FP drawings (Reference 14). Ebasco responded that walkdown data collection was p-rformed in accordance with TNE FVM CS-010 (Reference 13). Cygna has reviewed this document and has found it acceptable.

Status: A. Closed B. Closed C. Closed.

D. Closed.

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References:

1. Communications Report between T. Keiss (TU Electric) and W.

Horstman et al (Cygna), dated October 16, 1984

2. Communications Report between T. Keiss (TU Electric) and J.

Russ and N. Williams (Cygna), dated October 27, 1984

3. Communications Report between S. hicBee (TU Electric) and D.

Leong (Cygna), dated April 16, 1985

4. Communications Report between W. Zehe (Triangle PWC) and D.

Leong and J. Russ (Cygna), dated April 17, 1985

5. Communications Report between S. hicBee (TU Electric) and D.

Leong (Cygna), dated April 18, 1985

6. Communicatiors Report between S. hicBee (TU Electric) and J.

Russ (Cygna), dated hiay 7,1985 .

7. TU Electric Instruction CP El 4.0-49
8. Gibbs & Ilill I? awing 2323-S-0910.
9. Gibbs & liill Drawing 2323-S-0910.
10. Gibbs & }{ill Calculation 2323SCS-1017, Set 1
11. TU Electric SDAR CP-85-19, "Conduit Support Span Tests,"

dated May 15,1%5

12. J. Richards (Cygna) letter to W.G. Counsil (TU Electric),

"Conduit Support Review Questions," 84056.110, dated afarch 18, 1987

13. Transcripts of Conduit Supports, Cable Trays, Pipe Stress and Pipe Support Design Verification hiceting among TU Electric, Cygna, SWEC, Impell and Ebasco, dated hfarch 24 and 25,1987
14. Ebasco Specification SAG.CP10, "Unit 1 Design Criteria for Seisn.ic Category I Electrical Conduit System," Revision 7 i -

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15. Communications Report between HS. Yu et al (Ebasco) and J.

Russ (Cygna), dated July 21,1987,1030 a.m.

16. Communications Report between S. Harrison et al (TU Electric) and J. Russ et al (Cygna), dated October 1,1987, 9.25 a.m.
17. Communications Report between S. Harrison (TU Electric) and D. Leong (Cygna), dated February 10,1988, 3:00 p.m.

Summary: T2 Slectric Instruction CP EI-4.0-49 (Reference 7) gives allowable cons spans for fire protected runs. Cygna noted that, in most case the fire protected spans exceed the allowable spans for tected conduit spans documented in the 2323-S-0910 drawing ut,kage pac (References 8 and 9)

Cygna reviewed the design calculations for the fire protected spans (Reference 10) and concluded that the increase in length for the fire protected spans could be attributed to the removal of conservatisms from the analysis, such as using the refined rather .

than the unrefined spectra. In general, Cygna agrees with the analysis method used in the span design; however, Cygna does not agree with the conduit stress allowables used in the analysis.

Ta obtain allowable stress values for the conduits, Gibbs & Hill used test data supplied by the vendor to obtain yield stress values. Cygr:a has two major comments on the derivation of the allowables:

o The allowable stress values vary with conduit nominal size.

The vendor test data consists of three to four tests for specimens of each conduit size. Gibbs & Hill used the lowest tested yield stress for each conduit size or an imposed minimum yield stress value of 33 ksi to obtain allowables for that particular conduit size. Justification for the imposed minimum yield stress value was not provided. Cygna feels that it is not appropriate to specify different allowable stresses for each conduit size.

o Gibbs & Hill did not provide documentation to justify the j

l applicability of the vendor test data to the conduits installed at CPSES. Cygna understands that electrical conduit is l fabricated in accordance with ANSI C80.1, which does not contain requirements for material conformance.

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8/19/88 Revision 4 Page 100 CONDUIT SUPPORTS Review issues List Cygna spoke to Triangle PWC, the conduit supplier for CPSES, regarding the test data provided to Gibbs & Hill (Reference 4).

Triangle PWC informed Cygna that as a rule, no certification test reports are provided with the product and that any test data in the public domain represented a general sample of conduit they have produced. They also stated that Triangle PWC is a processor and does not manufacture the steel used for the conduits. There are no ASTM standards applicable to conduits.

The items discussed above concerning the conduit allowable stress apply to all conduit span calculations performed by Gibbs & Hill.

Cygna has one comment on the method used for the calculation of conduit stress. A dynamic amplification factor (DAF) of 1.0 was used in the conduit stress evaluation without justification. Review Issue 2 ditcusses the reanalysis efforts by Gibbs & Hill to address this concern. Results of those reanalyses should be applied to the conduit .

stress analyses described here.

Response: o Conduit material yield stress has been evaluated based on Material Test Reports (MTRs) in the response to SDAR

CP-8519 (Reference 11) Cygna audited Reference 11 and I verified that conduit yield stresses were based on the minimum tested value in this document and were consistent with properties for conduit materials used in the industry. The allowable stress values have also been incorporated into SAG. CP10 (Reference 14).

l o Since all Thermolag is being removed, and the locations for its use redefined, Ebasco will reanalyze the conduits based on the i final installed configurations.

Status: Closed.

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23. Grouted Penetrations

References:

1. Communications Report between R. Kissinger and S. hicBee (TU Electric), P. Huang (Gibbs & Hill R. hiiller and R. Yow (CCL) and D. Leong and J. Russ (Cygna dated April 10, 1985
2. J. Richards (Cygna) letter to W.G. Counsil (TU Electric),

"Conduit Support Review Questions" 84056.110, dated hfarch 18, 1987

3. Transcripts of Conduit Supports, Cable Trays, Pipe Stress and Pipe Support Design Verification hiceting among TU Electric, Cygna, SWEC, Impell and Ebasco, dated hfarch 24 and 25,1987
4. Communications Report between H. Gandhi et al (Ebasco) and B. Shakibnia et al (Cygna), dated July 22,1987, 905 a.m. and 1:20 p.m.
5. Ebasco Calculation Book No.151,"Conduit Concrete Embedment ,

Requirements at Penetration," Revision 1

6. Ebasco Specification SAG.CP25, "Iso Verification Guidelines,"

Revision 1

7. Communications Report between R. Alexandru et al (Ebasco) and D. Leong et al (Cygna), dated July 23,1987, 500 p.m.
8. Communications Report between H.S. Yu (Ebasco) and B. Shakibnia (Cygna), dated August 14,1987,1100 a.m.
9. Communications ibport between H.S. Yu et al (Ebasco); and B.

Shakibnia et al (Cygna), dated September 25,1987, 2:30 p.m.

10. Communications Report between R. Hatrison et al (TU Electric) and D. Leong et al (Cygna), dated October 1,1987, 9:25 a.m.
11. Communications Report between S. Harrison et al (TU Electric);

HS. Yu et al (Ebasco); and D. Leong et al (Cygna), dated biarch 25,1988, 9:40 a.m.

Texas Utilities Electric.

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12. Communications Report between S. Harrison et al (TU Electric); HS. Yu et al (Ebasco); and D. Leong et al (Cygna),

dated April 7,1988, 9:30 a.m.

13. Communications Report between S. Harrison et al (TU Electric); HS. Yu et al (Ebasco); and D. Leong et al (Cygna),

dated April 13,1988, 9.15 a.m.

14. Ebasco Specification SAG.CP10, "Design Criteria for Seismic Category I Electrical Conduit System," Revision 7 sum nary: For conduit runs embedded in v alls and floors, longitudinal conduit supports are not required if there are no bends in the run. The grouted penetrations are assumed to carry the entire longitudinal load for such a conduit run. Additionally, all grouted penetrations are assumed to be multi-directional supports, sharing conduit load with the supports closest to the penetration. Calculations were not performed to assure the capability of the penetration to carry the required loads. Other supports on the conduit run may also be .

affected depending on run configuration and relative stiffness of the supports.

Response: Grouted penetrations are no longer considered as conduit supports (Reference 4). Therefore, grouted genetrations are no longer a conwin; however, cast in place penetrations are addressed in this issue. In Ebasco Calculation Book 151 (Ref erence 5), Ebasco addresses cast in. place canduits. In tlis book, the length of conduit required to develop the required bond strength is calculated. This length will be different for different size of conduits. Ebasco has tabulated these V: lues in SAG.CP25 (Reference 6)

Cygna asked Ebasco to justify using "fixer and "hinged" boundaries at conduit penetrations (Reference 2) Eba:co explained that when designing the support adja:ent to the penetration, the boundary condition at the penetration was considered to be "hinged" to maximize load on the support. Conversely, when evaluating the icnetration bond stress, te obtain the most wnservative reaction at the penetration, the boundary condition at the penetratior, was considered to be "fixe & (Reference 3)

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t 8/19/88 Revision 4 Page 103 CONDUIT SUPPORTS Review Issues List Cygna also asked how the method for determining allowable bond stresses was technically supported and whether any testing was planned (Reference 2). Ebasco stated that testing of "cast in-place" conduits would not be performed. Ebasco uses the methodology of ACI318-63 for the allowable bond tress for plain reinforcing bars to calculate the allowable bond stress for conduits. Ebasco reasoned that conduits could be considered as plain reinforcing bars (Reference 3) The allowable bond stress for plain reinforcing bars is 50% of the bond stress allowed for deformed bars.

Cygna asked Ebasco about the applicability of allowable bond stress formulae (from ACI 318-63) to bar sizes greater than #18. Conduits of 2 inch diameter through 5 inch diameter would fall within this category. Detailed discussions on this matter are summarized in References 12 and 13. Ebasco also stated that the allowable bond stress values were listed in SAG.CPIO (Reference 14). Cygna reviewed these allowables, found them to be conservative (Reference 12), and have accepted their use. Ebasco has also revised SAG.CP25 (Reference 6) which reflects the required conduit lengths ,

for variou conduit diameters to develop allowable bond strength.

Status: Closed.

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24. Ri_idity e of CA-Tyne Suonorts

References:

1. Deleted
2. CCL Report No. A 678-85, "Seismic Qualification Test Report of Conduit Support Systems," Volumes I and II, dated October 9, 1985
3. Communications Report between H. Gandhi et al (Ebasco) and J. Russ et al (Cygna) dated July 22,1987, 9:05 a.m.
4. Ebasco Calculation Book Span.1010,"Support Frequency Requirements for Unit 1, Revision 1
5. Communications Report between R. Alexandru et al (Ebasco) and D. Leong et al (Cygna), dated July 23,1987, 500 p.m.
6. Communications Report between S. Harrison et al (TU Electric) and D. Leong et af. (Cygna), dated October 1,1987, 9.25 a.m. .
7. Communications Report between S. Harrison (TU Electric) and D. Leong (Cygna), dated February 10,1988, 300 p.m.

Summary: In the design of CA type supports, the rigidity of the conduit spans was checked to justify the use of ZPA in calculating the design loads for the supports. In determining the rigidity of the conduit spans, Gibbs & Hill assumed that the CA type supports were rigid. The frequencies of the conduit systems were due to the span flexure between rigid supports only. The design calculations for the CA type supports did not include stiffness evaluations to validate the assumptions.

Response: The frequency for CA type supports in Unit i v/ill be computed. For a discussion of the design verification of CA type supports, see Review Issue 13.

There are two types of CA type supports, Unistrut and assemblies of structura; shapes and plates. Unistrut types have been tested.

Cclculations based on the test results (Reference 2) have shown that all of these r.re rigid, i.e., support frequency 2 33Hz. See Review Issue 8 'or further discussion. The frequencies of the types made of structuial shapes and plates have been ca?culated and, in some Texas Utilities Electric Comanche Peak Steam Electric Station

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8/19/88 Revision 4 Page 105 CONDUIT SUPPORTS Review Issues List instances, were found to be less than 33 Hz. In the current design verification work, all supports ere evaluated using desigu "g" values.

Support frequencies are limited to 1216 Hz rather than the 33 Hz previously required for CA type supports.

Cygna reviewed the frequency calculation for support CA 15 and found the method to be acceptable and consistent with the commitments.

Status: Closed.

Texas Utilities Electric Comanche Peak Steam Electric Station

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25. Envelonine Configurations for Desien

References:

1. Deleted
2. Deleted
3. Ebasco Specification SAG.CPIO,"Unit 1 Design Criteria for Seismic Category I Electrical Conduit System," Revision 7
4. J. Richards (Cygna) letter to W.G. Counsil (TU Electric),

Conduit Support Review Questions," 81056.110, dated March 18, 1987

5. Transcripts of Conduit Supports, Cable Trays, Pipe Stress and Pipe Support Design Verification Meeting between TU Electric, Cygna, SWEC, Impell and Ebasco, dated March 24 and 25,1987
6. Communications Report between HS. Yu et al (Ebasco) and J.

Russ (Cygna), dated July 20,1987, 9.50 a.m. ,

7. Communications Report between S. Harrison et al (TU Electric) and J. Russ et al (Cygna), dated October 1, 1987, 925 a.m.
8. Communications Report between HS. Yu (Ebasco) and D. Leong (Cygna), dated January 28,1988, 4:45 p.m.
9. Communications Report between S. Harrison (TU Electric) and D. Leong (Cygna), dated February 10,1988, 3.00 p.m.
10. Communications Report between S. Harrison et al (TU Electric);

HS. Yu et al (Ebasco); and D. Leong et al (Cygna), dated March 2,1988, 9:40 a.m.

11. Communications Report between S. Harrison et al (TU Electric); HS. Yu :t al (Ebasco); and D. Leong et al (Cygna),

dated March 25,1988, 9:40 a.m.

i Texas Utilities Electric Comanche Peak Steam Electric StGion

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12. Communications Report between S. Harrison et al (TU Electric); H.S. Yu et al (Ebasco); and D. Leong et al (Cygna),

dated April 7,1988, 9.30 a.m.

Summary: Since the Gibbs & Hill generic supports have numerous design parameters and tolerances for installation, the design must be evaluated for the worst case configuration allowed by the drawing.

Cygna has noted several cases where the model used in the design evaluation did not reflect the most critical support configuration.

Additionally, the models used to check the perceived critical component were used to check other components whose forces were not maximized in the design model. The following supports are affected.

o CA la o CA 2a o CASA o CSht 18f o CSht42

  • o CST 3 o CST 17 o IN CSM 15a The maximum load eccentricities and installation tolerances are elso not considered in the Gibbs & Hill designs. The following generic supports are affected:

o CA la o CA 2a o CASA o CShi6b o CSM 18b o CSM 18e o CSM 18d o CSM 18f o CSM-42 o CST-3 o CST 17 o JA 1

'lexas Utilities Electric Comanche Peak Steam Electric Station

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.s Review Issues List The foliowing individual supports are affected:

o IN CSM 15a o C12G031261 o C12G0312611 Component substitutions and any related tolerances should also be considered. See Review Issues 4, 5,10,12,13,17, and 18 for substitutions and tolerances allowed generically. This review issue is similar to concerns regarding enveloping configurations for the Unistrut testing scope discussed in Review Issue 9.

Response: Generic conduit supports were design verified for the worst configuration which incorporated critical support orientation, conduit load eccentricities, baseplate installation tolerances, and the dead and inertial weight of the support, including cover plates and overhangs.

Modified and Individually Engineered (IN) supports would be design verified for the actual installed condition, except the as-designed welds for which weld related CMCs are used (Reference 5). Cygna- ,

asked Ebaxo to substantiate the assumption that the weld documentation is correct, with respect to the installation Ebasco documentation stated that the QA/ errors discussed OOC activities in Issueacceptab had evaluated 19 (Reference 4) ility of the weld documentation and the physical installation and had concluded that this assumption was valid.

Critical conduit load eccentricities were determined based on the maximum conduit size attached to the support and the maximum combined thickness of shim and filler plates. The minimum bolt distances were used in the baseplate finite element analysis to account for prying action on the anchor bolts. Cover plate weight

was provided at the tip of all tube steel members. Overhang length l was determined based on maximum dimensions. The effects of bolt and/or member substitution have been discussed in Review Issues 12 and 17, and installation tolerances have been considered for base plates and tube steel location on the base plate. Other installation tolerances were inherently included by considering maximum permissible dimensions.

l Cygna asked how the general notes and other allowances of S-0910 package were included in Ebasco's generic support design verification.

They also asked how these generic supports were evaluated so that Texas Utilities Electric Comanche Peak Steam Electric Station

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8/19/88 Revision 4 Page 109 CONDUIT SUPPORTS Review Issues List all revisions of the drawings and general notes were enveloped by the design verification (Reference 4) Ebasco responded that all general notes and other allowances were reviewed and incorporated as

, applicable into the revised S-0910 package. Items which could not be substantiated by analysis would be identified during the walkdowns.

At that point, all the isometrics would be evaluated against the revised S-0910 packs;e for acceptance (Reference 5)

In Section II.A, page 6, of SAG. TUG 1341, a discussion of loading the support to maximize the structural member stresses is given.

Cygna asked what assurances were made to maximize forces and stresses in other components as well (Reference 4) Ebasco stated that, for supportr. where application of loads at one location did not produce maximum stresses on all structural components, additional computer analysis were performed by applying loads at other critical locations which would produce maximum stresses on structural components (Reference 5)

Working point eccentricities were considered in accordance with pages .

12 17 and page 33 of SAG. TUG 1341. For the generic design verifications, the worst case workir.g point eccentricities shown in the S-0910 package would be considered. After the walkdown is completed, if the actual working point eccentricities are more than that used in the generic design, reconciliation of working point eccentricities would be performed (Reference 5)

The adequacy of the conduit attachment details referenced in Ebasco Calculation Book No. 8, Section 3, Paragraph 4, has been verified in Calculation Book 44. Cygna asked if the verification was performed through analysis or by comparison to test results (Reference 4)

Ebasco responded that the original calculation contained in Calculation Book 44 was based on allowables which differed from the CCL test results. With the availability of new allowables based on the CCL test results, Book 44 has been updated accordingly.

Cygna asked if the "beam element" noted in Section 4.5.1 of Ebasco Calculation Book No. 8, accounted for the shear center offsets and, if not, how torsional effects were considered (Reference 4) Ebasco responded, and Cygna verified, that the shear center offset was not considered in the modeling; however, this offset was considered manually when calculating the torsional moment.

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26. Desian Drawine Discrenancies

References:

L Gibbs & Hill Drawing 2323-S-0910, Sheets and Revisions noted below.

o CSD 2, Revision 1 o CShi-6b, Revision 3 o CShi18b, Revision 16 '

o CSht 18c, Revisions 12, 13, 14 o CShi18d, Revision 9 o CSht 18f, Revisions 3, 4, 5 o IN-CSht 15a, Revision 6

2. J. Richards (Cygna) letter to W.G. Counsil (TU Electric),

"Conduit Support Review Questions," 84056.110, dated h1 arch 18, 1987

3. Transcripts of Conduit Supports, Cable Trays, Pipe Stress and Pipe Support Design Verification hiceting between TU Electric, .

Cygna, SWEC, Impell and Ebasco, dated hiarch 24 and 25,1987 Summary: In the review of generic conduit support designs in the original S.

0910 package, Cygna has compared the design drawings with the assumptions and models used in the support evaluations. The following discrepancies or inconsistencies were noted in the design drawings.

o The baseplate size on detail drawing CSD-2, Revision 1 was not given.

o For CSht 6b, Revision 3, the capacity table rertricts the conduit size to 1" diameter or less. The drawing has a note specifying that C 708-S clamps must be used for conduits greater than or equal to 2" in diameter. This note is superfluous, considering the size limitation on the capacity table, o The clamp type was not noted on the support drawings for CSht 18b, CShi 18c, CSht 18d, and CShi 18f.

o No edge distance for the clamp bolts is provided for the angle bracket in IN-CShi 15a.

l Texas Utilities Electric

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8/19/88 Revision 4 Page 112 CONDUIT SUPPORTS Review Issues List o The design drawing for CSM 18e has no conduit size tables, but there is a superfluous note on the drawing regarding the nonexist:nt table.

Response: The design verification of S-0910 package is complete, and all generic drawings will be reissued. Only those modified and individually engineered (IN) drawings which are not acceptable in the design verification will be reissued. Verification of modified and IN supports is in progress.

Cygna asked how the resolution would ensure that the supports installed using current and previous revisions of drawings, with missing information, were adequate (Reference 2). Ebasco responded that the installed supports were being redlined to reflect the as-built condition. These would be reviewed against the revised S-0910 package during the ISO evaluation process. Since all revised S-0910 packages would be updated for all information necessary for the design verification, drawing sheets with missing information would -

not occur (Reference 3).

Status: A. Closed.

B. Closed.

C. Closed.

D. Closed.

E. Closed.

F. Closed.

Texas Utilities Electric Comanche Peak Steam Electric Station

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27. Walkdown Discrenancies l

References:

1. Deleted
2. (

N.H. Williams "Conduit Support(Cygna)

Walkdownletter to J.B. George (TU Electric 840%020 Questions" August 13, 1984

3. Lhi. Popplewell (TU Elect:ic) letter to N. Williams (Cygna),

transmitting calculations in response to Cygna questions, dated August 31, 1984

4. Lht. Popplewell (TU Electric) letter to N. Williams (Cygna),

transmitting calculations in response to Cygna questions, dated September 11, 1984

5. Lht. Popplewell (TU Electric) letter to N. Williams (Cygnal transmitting calculations in response to Cygna questions, dated September 18, 1984 .
6. N.H. Williams (Cygna) letter to W.G. Counsil (TU Electric),

"Cable Tray / Conduit Support Review Questions" 840 % 094, dated Ohber 30, 1985

7. J. Richards (Cygna) letter to W.G. Counsil (TU Electric),

"Conduit Support Review Questions," 840 % 110, dated h1 arch 18, 1937

8. Transcripts of Conduit Suppotts, Cable Trays, Pipe Stress and Pipe Support Design Verification hiceting between TU Electric, Cygaa, SWEC, Impell and Ebasco, dated h1 arch 24 and 25,1987
9. Communications Report between S. Harrison et al (TU Electric); T. Kuo (Ebasco); and D. Leong et al (Cygna), dated August 31,1987, 9 30 a.m.
10. Communications Report between R. Beam et al (Ebasco) and J. .

Russ (Cygna), dated September 1,1987, 9:00 a.m.

11. Communications Report between C.Y. Chiou (Ebasco) and J.

Russ et al (Cygna), dated September 2,1987,11:45 a.m.

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12. Communications Report between R. Beam (Ebasco) and J. Russ (Cygna), dated September 4,1987,12:30 p.m.
13. Communications Report between S. Harrison et al (TU Electric) and J. Russ et al (Cygna), dated October 1, 1987, 925 a.m.
14. Communications Report between S. Harrison et al (TU Electric); HS. Yu et al (Ebasco); and J. Russ et al (Cygna),

dated April 7,1988, 930 a.m.

15. Communications Report between S. Harrison (TU Electric); HS.

Yu et al (Ebasco); and J. Russ et al (Cygna), dated April 14, 1988, 900 a.m.

16. Communications Report between S. Harrison et al (TU Electric); HS. Yu et al (Ebasco); and J. Russ et al (Cygna),

dated April 25,1988, 9.00 a.m.

Communications Report between S. Harrison et al (TU 17.

Electric); HS. Yu et al (Ebasco); and J. Russ et al (Cygna),

dated April 25,1988,100 p.m. .

18. Communications Report between S. Harrison et al (TU Electric) and J. Russ et al (Cygna), dated April 27, 1988, 1035 a.m.
19. Communications Repcit between S. Harrison et al (TU Electric); HS. Yu et al (Ebasco); and J. Russ et al (Cygne dated April 27,1988, 3:15 p.m.
20. TNE-FVM CS-033, "Design Control of Electrical Conduit Raceways for Unit 1, installation in Unit 1 and Common Areas, Revision 2 Texas Utilities Electric Comanche Peak Steam Electric Station

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8/19/88 Revision 4 Page 115 CONDUIT SUPPORTS Review Issues List Summary: The Cygna walkdown noted a number of conduit support discrepancies discussed below.

A. Clamp Installation

1. Clamp distortion was noted in four supports. This is discussed in Review Issue 18.
2. Gaps Between Clamps and Shims The maximum gap allowed between the ears of a P2558 clamp and the shim plate is 1/8". Cygna noted two supports with gaps in excess of the 1/8". These supports are:

o C13G028511 o C120029351 B. Anchor Bolt Installation ,

1. Hilti Expansion Anchor Proximity Violation Th:re are five occurrences of Hilti proximity violations where the spacing in the field between the supprt and Hilti expansion anchors in adjacent supports is less than the mimmum distance used in the design. The affected supports are:

o C13G03528-1 o C12G03126-21 (two occurrences) o C12G050871 o C12605087 2

2. Hilti Expansion Anchor Placement Violation Cygna has noted three supports with field installations of Hitti bolts which differ from the installations in the design drawings and/or CMCs. The affected supports are:

o IN-CSM 15a o C120052541 o C12G03126-16 Texas Utilities Electric Comanche Peak Steam Electric Station Independent Assessment Program - All Phases millitilllismillitill$ill Job No. 84056 \TUE\84056\23CS ISS t

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8/19/88 Revision 4 Page 116 CONDUIT SUPPORTS Review Issues List The placement violation for one Hilti Kwik bolt on support IN-CSht 15a results in a concrete edge distance violation.

3. Richmond Insert Installation Cygna noted that both Richmond Inserts on support C1200312612 were not properly seated, such that they were not bearing flat against the base angles.
4. The base angles for IN-CShi15a were installed such that the angle legs do not bear flat against the concrete.

There is a gap of 1/4" between the angle and the concrete near the tube, which decreases to zero at the toe of the angles.

C. Installation of Structural Steel

1. Installation Tolerance Cygna noted two supports with installation tolerances in excess of those provided on the design drawing-
a. For support C13G03528-3, the tolerance for attaching the tube steel to the base plate was exceeded.
b. For IN-CSht 15b, the brace member work points are not coincident with the tube steel workpoints as shown on the design drawing.
2. hiember Size For IN CSht 15b, the baseplate for the horizontal brace is 19-3/4" long. The maximum size allowed on the design drawing is 18" Texas Utilities Electric Comanche Peak Steam Electric Station

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1. Seating of Unistrut Nuts One put in C12G03126-13 and four nuts in C12G0312642 were not properly seated in the Unistrut channels.
2. Member Substitution P5000 members were used as header members in C12002935 instead of P1001 members, as specified in the ,

design drawing.

3. Member Rotation The brace member in C12G0312614 was rotated 180 about its own axis from the orientation shown on the design drawing.
4. CSD-1 Connection Installation Cygna noted installation discrepncies for the CSD-1 connectior.s in supports C12G03126-12 and C12G03126-13.
a. Five connections were skewed, such that the header and base angle were not square relative to one another.
b. Four connections had gaps between the header and base angle in excess of the 1/4" allowed by the design drawing.
5. The outriggers in C13G02851-4 are skewed with respect to the header. The outriggers should be perpendicular to the header.

Texas Utilities Electric Comanche Peak Steam Electric Station

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l 8/19/88 Revision 4 Page 118 CONDUIT SUPPORTS E.eview Issues List E. Conduit / Pipe Interferences Five pipes or conduits not supported by the support in question are in contact with the following conduit supports:

o C12G03126 21 o C12G0312618 (3 occurrences) o C12G0312619 F. Conduit Placement L Spacing Violation The minimum distance between the flexible conduits is given as 10-1/2" on the design drawing. The conduits on one tube are 10' away from the conduits on the other tube.

2. Rotation of Conduit Attachments .

The three conduits attached to the TS 6x3 member on IN CSM 155 are shown to be perpendicular to the tube steel on the design drawing. The conduits are skewed with respect to the tube steel in the field installation.

Response: All conduit runs will be walked down, and an isometric drawing with details of each support will be generated as required. The conduit I runs will then be design verified against the revised S-0910 package or analyzed according to the methods and requirements of the Ebasco specification.

Cygna reviewed the walkdown and data collection procedures and asked Ebasco to discuss the walkdown tolerances with respect to construction tolerances. Cygna also asked if the documentation l

i discrepancies in the Inspection Reports were addressed in the l walkdown (Reference 7)

Ebasco indicated that the Unit I walkdown effort was performed in accordance with Reference 20. Reference 20 includes tolerances for l

inspection or checking purposes which are more relaxed compared to

' installation tolerances. The walkdown data collection was based on l actual measuremenu which Ebasco stated to be within 1/16th of an l

- - + - - " -

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CONDUIT SUPPORTS Review issues List inch, except for thickness. Documentation discrepancies were not specifically addressed by the walkdown program (Reference 8)

Cygna had a number of questions on walkdown procedure TNE FVM-CS-016, Revision 1 (Reference 7) Through discussions with Ebasco (References 8 and 15), the following information was obtained-

  • The Visual Weld Acceptance CrNria (VWAC) is applicable and was used. As a rule welds were measured during the walkdown process.

In the event the checker documented new or more information than the originator, then the checker must reconcile the differences with the originator. If a major discrepancy or incompleteness was noted then the checker may require the originator to as build the attribute again. The final responsibility of correctness and completeness remains with the checker.

Cygna also reviewed and discussed Ebasco's walkdown procedures /

instructions which pertained to measuring and checking of anchorage tolerances. Upon such review and follow up discussions Cygna accepted Ebasco's methodology and closed the issue (References 16 and 18)

Status: A. Closed.

B. Closed.

C. Closed.

i D. Closed.

E. Closed.

I F. Closed.

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References:

1. N.H. Williams (Cygna) letter to J.B. George (TU Electric),

"Cab'e Tray and Conduit Support Review Questions" 84056.015, dated August 6,1984

2. Gibbs & Hill Calculation 2323-SCS153C, Set 1, Sheets 153-160
3. Gibbs & Hill Calculation 2323-SCS.152C. Set 1, Sheet 38
4. Gibbs & Hill Calculation 2323-SCS-102C, Set 2, Sheets 255-258 (Revision 2)
5. J. Richards (CyBna) letter to W.G. Counsil (TU Electric),

"Conduit Support Review Questions," 84056.110, dated March 18, 1987

6. Transcripts of Conduit Supports, Cable Trays, Pipe Stress and Pipe Support Design Verification Meeting between TU Electric, .

Cygna, SWEC, Impell and Ebasco, dated March 24 and 25,1987

7. Communications Report between H. Gandhi et al (Ebasco) and B. Shakibnia et al (Cygna), dated July 22,1987, 905 a.m. and 1:20 p.m.
8. Communications Report between HS. Yu (Ebasco) and B.

Shakibnia (Cygna), dated July 23,1987, 510 p.m.

9. Communications Report between HS. Yu (Ebasco) and B.

Shakibnia (Cygna), dated August 11,1987, 5 20 p.m.

10. Ebasco Specification No. SAG.CP10, "Unit 1 Design Criteria for Seismic Category I Electrical Conduit System," Revision 7
11. Ebasco Specification SAG.CP2, "Unit 2 Design Criteria for Seismic Category I Electrical Conduit System," Revision 9
12. Communications Report between S. Harrison et al (TU Electric); HS. Yu et al (Ebasco); and D. Leong et al (Cygna),

dated April 7,1988, 9:30 a.m.

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13. Commuaications Report between S. Harrison (TU Electric); HS.

Yu et al (Ebasco); and D. Leong et al (Cygna), dated April 14, 1988,1:30 p.m.

14. Communications Report b: tween S. Harrison et al (TU Electric); HS. Yu et al (Ebasco); and D. Leong et al (Cygna),

dated April 25,1983, LOO p.m.

15. Communications Report wtween S. Harrison et al (TU Electric); H.S. Yu et al (Ebasco); and D. Leong et al (Cygna),

dated April 27,1988, 3:15 p.m.

Summary: For the majority of supports in the 2323 S-0910 package, the design evaluations are performed for individual supports with applied point loads representing the conduit. Loads from all restrained directions and tributary spans are applied to the support model. However, for the design evaluation of CA Sa supports and the CSD-la detail (Zclip), the interaction between supports on a conduit run or between the support and the conduit is used to validate use of '

reduced loads on the support or connection.

In Ref:rences 2 and 3, Gibbs & Hill uses a load couple between adjacent CA Sa supports to resist longitudinal loads. The rigidity of the conduit to provide transfer of longitudinal load to tensile load on the adjacent clamps was not shown. The use this configuration requires specific field installation of supports (CA Sa supports in '

series on a straight run). Its generic application in conjunction with other support types and in conduit runs with bends and offsets was not considered.

In Reference 1, Cygna asked Gibbs & Hill to consider the impact of the eccentricities for the design of CSD-la details. '1U Electric /Gibbs & Hill submitted Reference 4 in response to Reference

1. In the response calculations, Gibbs & Hill assumed that the conduit attached to the, support provided bracing for the support in the longitudinal direr.(ion, preventing rotation of the support and CSD la detail.

The calculation '.n Reference 4 makes generalized configurational and load assumptior.s for both the support and conduit system. The applicability of the calculation to all supports using this detail, for both multidirectional and trensverse supports should be demonstrated.

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This affects supports CSM-65, CST 3, and CST 17 in Cygna's review t scope.

Response: For concrete surface mounted supports with two. bolt baseplates, the design verification of conduit support capacities considered the moments induced in the conduit / support system by the longitudinal loads and their eccentricities. These loads will be shared between the conduit and the support according to the stiffnesses of the l system components. Section 9.0 of References 10 and 11 define the load eccentricities and criteria for the design verification.

The concept of load coupling between adjacent supports previously used by Gibbs & Hill is not used. However, the reactions at the supports from possible load coupling are considered to be negligible.

Cygna asked Ebasco following qu-9ns on the concept of shared moments between coaduit supports (Reference 5):

o What is the basis for the concept of shared moments? .

o How has the moment transfer between the conduits and supports through the clamps been addressed?

o How were system models used for this verification effort?

o Have varia' ions in span lengths and configurations been considered? If so, how were they chosen to envelop the total population?

Ebasco provided *he following response:

There are three components of conduit load induced by seismic conditions- Vertical to the conduit, transverse to the conduit, and longitudinal along the axis of the conduit. The vertical force is acting perpendicular to the two bolt base plate. The transverse force is acting parallel to the two bolt centerline. The longitudinal force is acting perpendicular to the two-bolt centerline. The vertical load is transmitted directly to the baseplate. The transverse load induces a moment and a shear in the support base plate. In this case, the entire moment and shear is resisted by the base plate. The system concept is not used for the vertical and transverse loads. The longitudinal load also induces a moment and shear in the baseplate.

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8/19/88 Revision 4 Page 123 CONDUIT SUPPORTS Review issues List The moment induced by the longitudinal load is shared by the conduit and the support baseplate in proportion to the stiffness of the components. The conduit ancl clamp must rotate together to validate this concept.

The moment absorbed by the conduit is resisted ty its rotational stiffness with coupling of the adjacent supports and bends. For various sizes of conduits, the moment taken by the conduit ranges from 68% to 90% of the total longitudinal moment at the support location. The load cou aling is relatively small and is considered to be of negli ible vertica effect. The magnitude of the coupled load is proportion to the ratio of the span to the vertical eccentricities of the conduit.

The allowable loads on the clamps are established in the testing program, which accounts for moment transfer between the conduits and the supports thraugh the clamps.

Cygna was concerned that the proportion of the longitudinal moments

  • applied to the baseplate was not conservative for all configurations of conduit spans (Reference 7) Ebasco performed additional calculations for configurations with pinned vs. fixed boundaries, conduit bends, and overhangs. These additional analyses showed that there were a few cases which fell outside the set limits of moment distributed to the baseplates (References 12 through 14) Ebasco revised SAG.CP25 to reflect the exceptions to those conduit runs where the "system concept" was applied (Reference 15)

Status: Closed.

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References:

1. TU Electric, Generic Issues Report, "Evaluation and Resolution of Generic Technical Issues for Conduits and Conduit Supports" Revision 2
2. TU Electric, Corrective Action Program, "Conduit Supports Trains A and B and Train C Larger than 2 Inch Diameter,"

Revision 0

3. Communications Report between S. Harrison et al (TU Electric);

H.S. Yu et al (Ebasco); and D. Leong et al (Cygna), dated April 25,1988,1:00 p.m.

Summary: In this Review Issues List, a number of the issues cited may lead to small 'unconservatisms when occurring singly in a support design and can usually be neglected liowever, since several of these issues pertain to all conduit support designs on a generic basis, their effect can be cumulative, such that many small unconservatisms may be ,

significant. Therefere, any reevaluation of support designs should consider the cumulative effect of all pertinent Review Issues.

Response: TU Eleutic stated that this issue is resolved by the conduit and conduit support Corrective Action Program (CAP) and its 3

comprehensive engineering approach to design validation of conduits and conduit supports and by the implementation of extensive as-built analysis, validation and some test activities (References 1 and 2).

The conduit and conduit support design validation procedures include consL1: ration of variances between the original design and as-built conduit support systems, control of design documents, analysis assumptions and methods, and design assumptions and methods.

The as-built information necessary to verify compliance of conduits and condult. supports with design criteria was obtained by walP. downs conducted by experienced Ebasco personnel trained in accordance with the walkdown procedures. The results were used to create as built drawings of the conduit and conduit supports.

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 w -

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l validation calculations for conduit and conduit supports in the Unit 1 l and Common areas. l l

Analyses assumptions and methods and design an.imptions and criteria have been addressed by the development of procedures and instructions, supported by engineering studies, which have systematically considered each issue.

In s ' mary, the design validation program has resolved the technical eth individually and collectively, provided as-built ntation of the conduit system designs and confirmed the u ,ervatism of the design validation approach through appropriate testing. During the design verification process no allowance for increasing the allowables based on ANCO test results has been made.

This practice indicates additional safety margin in design verification process. The design validation program assures that the design of conduit systems is in conformance with the licensing commitnents and, therefore, the margin of safety is acceptable.

Cygna has reviewed and summarized all aspects of the conduit 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 Ebasco in studies performed as a pa:. of the conduit system verification program (Reference 3).

Status: Closed.

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