ML20127G893

Forwards Rev 10 to Cable Tray Support Review Issues List & Rev 1 to Design Control Review Issues List as Part of Independent Assessment Program.Current Revs for Other Disciplines Remain as Transmitted on 850423

ML20127G893
Person / Time
Site:	Comanche Peak
Issue date:	06/21/1985
From:	Williams N CYGNA ENERGY SERVICES
To:	Beck J TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
References
84056.072, NUDOCS 8506260127
Download: ML20127G893 (59)

Text

M 101 California Street, Suite 1000, San Francisco, CA 941115894 415 397 5600 June 21, 1985

, 84056.072 l l

Mr. J.W. Beck Manager - Licensing Texas Utilities Generating Company l Skyway Tower l 400 North Olive Street, L.B. 81 i Dallas, Texas 75201 1

Subject:

Review Issues List Transmittal l t Comanche Peak Steam Electric Station i Independent Assessment Program - All Phases Job Nos. 83090, 84042 and 84056 l

Reference:

N.H. Williams (Cygna) letter to J.W. Beck (TUGCO),

I " Review Issues List Transmittal," 84056.064, l dated April 23, 1985

Dear Mr. Beck:

Enclosed are the latest revisions to the Cable Tray Support and Design Control l Review Issues Lists (RIL). These lists summarize all the findings and open items l identified to date. The current RIL revisions for other disciplines remain as transmitted by the above referenced letter. The enclosed RIL revisions are as follows:

o Cable Tray Supports, Revision 10 o Design Control, Revision 1 l All significant changes or additions are noted by a revision bar in the right I margin. These lists are still being reviewed by Cygna personnel on a weekly basis and will to be reissued as necessary. If there are any questions, please do not hesitate to call.

Very truly yours, e d(,WL,43 N.H. Williams Project Manager NHW/ajb l Attachments l cc: -Mr. V.- Noonan (USNRC) w/ attachments

! Mr. S. Burwell (USNRC) w/ attachments Mr.S.Treby(USNRC)w/ attachments

! Mr. W. Horin (Bishop, Liberman, et al.) w/ attachments l Mr. J. Redding (TUGCO) w/ attachments l Ms. J. van Amerongen (TUGC0/EBASCO) w/ attachments Ms. J. Ellis (CASE) w/ attachments Mr. D. Pigott (Orrick, Herrington & Sutcliffe) w/ attachments Mr. F. Dougherty (TENERA) w/ attachments Mr. R. Ballard (Gibbs & Hill) w/ attachments 1 Mr. R. Kissinger (TUGCO) w/ attachments 7/

San Francisco Boston Chicago Richland i I B506260127 850621 PDR ADDCK0500g5 g4

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' Revision 10 Page 1 CABLE TRAY SUPPORTS Review Issues List

1. Controlling Load Case for Design

References:

1. Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 5, Sheets 16-20, Revision 5

2. Communications Report between P. Huang, S. Chang (Gibbs & Hill) and J. Russ and W. Horstman (Cygna) dated November 13, 1984

3. Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 5, Sheets 1-7, Revision 1

4. CPSES FSAR, Sections 3.8.3 and 3.8.4 Summary: Gibbs & Hill design calculations (Reference 3) assumed that the design of cable tray supports was governed by the 1/2 SSE (0BE) seismic event. The assumption was based on a comparison between a 50% increase in seismic accelerations from the OBE event at 4% damping, the SSE event at 5% damp-ing, and an allowed increase in design stresses of 60% for the SSE event, per Reference 4.

For the design of structural steel members, the 60% increase cannot be applied to certain allowable stresses. For exam-ple, in weak axis bending of wide flange beams and bending in base plates, increasing the allowable by 33% will result in a stress level equal to yield. In addition, the allow-able loads for concrete anchors (also see Review Issue 3) cannot be increased by 60% for the SSE event. Neither of the above limitations were considered in the selection of the governing load case for design.

In order to reduce the loads for SSE, Gibbs & Hill elected to use 7% damping for the cable trays at SSE, as allowed for bolted structures.

Gibbs & Hill provided tables of peak spectral accelerations for OBE at 4% damping and SSE at 7% damping (Reference 1).

The reduced SSE accelerations appear to demonstrate that OBE governs for support designs on a generic basis. However, for supports designed using accelerations for a specific build-ing elevation (e.g., elevations 773', 785' and 790' in the Safeguards Building) the ratio of SSE to OBE exceeds 33%.

Therefore, SSE can potentially govern the design of these h -- Texas Utilities Generating Company eilf,j Comanche Peak Steam Electric Station

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6/21/86 Revision 10 Page 2 CABLE TRAY SUPPORTS Review Issues List supports. Support systems at these building elevations are not included in Gibbs & Hill's dynamic analyses. The sup-ports at the three elevations indicated above may require additional review.

Status: Qualification of supports within Cygna's scope is complete.

This issue should be considered in any cumulative effects evaluation for generic applications.

2. Seismic Response Combination Method

References:

1. CPSES FSAR Section 3.78.2.7

2. Gibbs & Hill Calculation Binder 2323-SCS-215C, Sets 2-6

3. USNRC Regulatory Guide 1.92, Revision 1

4. N.H. Williams (Cygna) letter to J.B. George (TUGCO), " Cable Tray Support Design Review Ques-tions," 84056.031, dated August 31, 1984

5. Gibos & Hill calculation response to IAP Pnase 2 questions, Cygna Technical File 83090.11.2.1.50 Sunmary: A. Closely Spaced Modes (10% Modal Combination) in Spectral Analysis l In the response spectra analyses performed for the l

working point deviation generic study (Reference 2),

l Cygna noted that modal responses were not combined I considering closely spaced modes as required by Refer-ences 1 and 3.

i B. Inclusion of Dead Load in SRSS Combination:

l l Gibbs & Hill design calculations typically included the l dead load in the SRSS with the seismic loads. This l issue was d'scovered in Phase 2 of this review, and l Gibbs & Hill performed a study to quantify the impact of l this error (Reference 5). Gibbs & Hill calculations did not consider the effects of frame aspect ratios on the resultant loads. Reference 4 discusses a Cygna study on

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6/21/85 s Revision 10 Page 3 CABLE TRAY SUPPORTS Review Issues List the effects of aspect ratios for frame types within the review scope. The study results indicated the increases in resultant loads by combining the dead load with the seismic SRSS may be larger than those predicted by Gibbs

& Hill .

Status: A. Gibbs & Hill has revised the working point analyses to account for closely spaced modes in accordance with Reference 3. For a discussion of other discrepancies in the working point deviation study, see Review Issue 12.

B. TUGC0/Gibbs & Hill should consider the effects of the worst case frame aspect ratio on the results of the SRSS study. The above issues should be considered in any evaluation of cumulative effects.

3. Anchor Bolt Design

References:

1. Gibbs & Hill calculations, " Evaluation of Detail 1, single-bolt connection," Cygna Technical File 84056.11.1.259

2. Gibbs & Hill Calculation Binder SCS-212C, Set 7, Sheet 4-11, Revision 0

^

3. Gibbs & Hill calculations, " Justification of the adequacy of 1" Richmond Inserts for the effects of prying action," Cygna Technical File 84056.11.1.219 Sunnary: A. Additional Tensile Forces Induced by Rotation of Base Angles About the Centerline of Bolt Pattern:

Gibbs & Hill has evaluated Alternate Detail 1 and a l single anchor base angle using A4 loads (Reference 1).

These loads were chosen since the questions regarding l design adequacy originated from discussion of the A4 l design. The resolution of this generic issue requires an evaluation of the worst case load and geometry for j all applicable supports. The geometries considered should include the effects of any generic change notices such as those for the base angle edge distance (CMC

! 1970) and the use of shims under base plates (CMC 1969).

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6/21/85 Revision 10 Page 4 CABLE TRAY SUPPORTS Review Issues List B. Safety Factor on Hilti Expansion Anchors at SSE Levels.

Also see Review Issue 1.

C. Inconsistent Application of ACI 349-76, Appendix B.

Gibbs & Hill has used the provisions of Reference 1 to qualify several designs. Examples include the qualification of anchorages for Detail "11" (Gibbs & Hill drawing 2323-S-0905, Reference 2) and the use of code provisions as justi-fication for the factors of safety used for Richmond In-serts. However, other code sections, such as B.7.3, which requires a factor of safety of 6.0 for single expansion anchor connections, were not adhered to. Cygna believes that the philosophy of the entire code appendix should be considered prior to employing selected portions of the code.

D. Factor of Safety on Richmond Inserts.

See Item C above.

E. Richmond Insert Design Allowables.

1. Prying action was not considered in the original design of Richmond Insert connections for cable tray supports. To qualify those connections which utilize Richmond Inserts, Gibbs & Hill performed calculations which reference the results of the

Richmond Insert testing program (Reference 3).

These calculations showed that Richmond Inserts were not the controlling anchorage type, but rather that the Hilti expansion anchors were the limiting case. Cygna has the following comments regarding these calculations:

a. The calculations do not account for the instances where the allowable values for Richmond Inserts from Gibbs & Hill Specification 2323-SS-30 (Ta = Va = 11.5 kips) were used without the prying factor. This situation could occur whenever a CMC was reviewed. Although Gibbs & Hill has stated that their engineers were instructed to include the WWNE Texas Utilities Generating Company Comanche Peak Steam Electric Station r eg' p2 i y

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Revision 10 Page 5 CABLE TRAY SUPPORTS Review Issues List prying factor, Cygna could not locate any supporting documentation.

b. The original design calculations for concrete connections utilizing Richmond Inserts employed allowable values of tension (Ta = 10.1 k) and shear (Va =

9.5 kips). With the issuance of Gibbs &

Hill Specification 2323-SS-30, restric-tions were placed on the allowable values for Richmond Inserts. These restrictions dealt with the use of Richmond Inserts in cluster arrangements and Ricnmond Inserts used in spacings less than those originally considered by Gibbs & Hill, through a corresponding decrease in allowable tensions and shears. Since these restrictions were imposed after the original design of the Richmond Insert connections was com-pleted, Cygna is concerned that they were not properly evaluated by Gibbs &

Hill. In discussions with TUGCO, Cygna was told that the smaller spacings of Richmond Inserts were for clustered areas that were reserved for whip re-straints. Any use of Richmond Inserts in these areas would require authoriza-tion from the responsible group and a corresponding evaluation of the install-ation.

F. Connection Designs.

The cable tray support designs provide for the use of angles or plates at base connections. Tnese designs also provide for various anchor bolt spacing and member placement tolerances. However, the use of these tolerances may thi produce concrete connections which are outside the design limits. ,Gibbs & Hill has not fully evaluated the effects of all possible installation tolerances on tne base member stresses or the anchorages.

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6/21/85 Revision 10 Page 6 CABLE TRAY SUPPORTS Review Issues List Cygna's Phase 2 Observations CTS-00-05 and CTS-00-07 respec-tively addressed the design of base connections for Detail "E" supports with three-directional loadings and Detail "A-D" base plate designs (drawing number 2323-El-0601-01-S).

g Due to the tolerances described above, these support connec-tion designs must also be reviewed to assure that the above concerns are addressed.

G. Justification of Prying Factor.

Gibbs & Hill designs globally used a factor of 1.5 to ac-count for the effects of base angle flexibility on anchorage tensile loads. The value of this factor is dependent on the applied load, bolt pattern geometry, and angle thickness.

No documented justification existed for the use of this factor.

H. Detail 1 Tolerances.

General note 14d on Gibbs & Hill drawing 2323-S-0901 and note 2 on Detail 1 of Gibbs & Hill drawing 2323-S-0903 allow the substitution of Richmond Inserts for Hilti expansion anchors which may result in a mixed connection of Richmond Inserts and Hilti expansion anctrors. Tne minimum Hilti anchor spacing is 15" while the minimum Richmond Insert spacing is 16". For base connections subject to moments, each anchor is designed for its respective minimum spac-ing. By substituting a Richmond Insert for a Hilti expan-d sion anchor at the Hilti spacing, the tensile load in the Richmond Insert is greater than the load the Richmond Insert has been qualified for. The effect of this substitution on Richmond Insert tensile loads has not been considered in the cable tray support designs.

1. Base Angle Boundary Condition Assumptions.

Gibbs & Hill has assumed the two-bolt base angles and the base angles for support type L-A3 on Gibbs & Hill drawing 2323-S-0902 as pinned connections. This assumption requires that the connection allow the calculated rotation without g

base connection failure. Gibbs & Hill has not justified such connection behavior.

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6/21/85 Revision 10 Page 7 CABLE TRAY SUPPORTS Review Issues List Status: A. Gibbs & Hill should provide justification for the use of A4 loadings for base plate and anchor bolt designs.

B. Cygna has collected data on the issue of the Hilti expansion anchor factor of safety and is evaluating it internally.

C. TUGC0/ Gibbs & Hill should provide justification for the use of the selected Appendix B sections.

D. Cygna has not found sufficient justification for the safety factor of 1.8 for Richmond Inserts under emer-gency/ faulted conditions.

E. Cygna requires verification that controls on the use of Richmond Insert allowables and the inclusion of a prying factor were in place and enforced by all responsible groups.

F. Gibbs & Hill must provide assurance that the installa-tion tolerances are properly accounted for in the base A connection designs. The at3ve issues should be con-sidered in any evaluation of cumulative effects.

G. Gibbs & Hill is to provide technical justification for the global usage of a prying factor of 1.5 for base angles.

H. Gibbs & Hill is to provide technical justification for

( the allowed bolt substitution.

Gibbs & Hill should provide technical justification for I.

the assumption of a pinned connection for two-bolt base connections and the connection for L-Ay type supports.

b

4. Design of Compression Members

References:

1. Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 1

2. Gibbs & Hill Calculation Binder 2323-SCS-215C, Sets 2-6 E- Texas Utilities Generating Company T4j.2 i f = Comanche Peak Steam Electric Station Independent Assessment Program - All Pnases IIlli!!Illilllllillllilli Job No. 84056

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3. N.H. Williams (Cygna) letter to J.B. George (TUGCO), " Cable Tray Support Review Questions,"

84056.022, dated August 17, 1984, question 4

4. Timoshenko and Gere, " Theory of Elastic Stability," 2nd Edition, pages 99 and 100 Sunenary: A. In the design of compression members for trapeze-type support frames, Gibbs & Hill did not consider the entire unsupported length of the channels in calculation of their slenderness ratios (Reference 1, Sheets 11 and 18 for support types A 4 and B4 , respectively). If the correct unsupported lengths as well as pinned ends are assumed, the slenderness ratio for these members will exceed 200, which is the limit for compression members per AISC Specification Section 1.8.4.

In order to reduce the slenderness ratios below 200, calculations were performed to show that k = 0.8 (Refer-ence 1, Sheets 128-146, Revision 3, and Reference 2).

These calculations assumed that rotational restraint is provided by the clip angle used to attach the hanger to the bottom of the slab. Additionally, since the com-pressive load is applied at several points over the length of the member, the allowable axial stress was increased based on the buckling analysis of columns witn multiple, discrete axial loads (Reference 4).

Cygna has analyzed one- and two-bolt clip angles under compressive loading and determined that it is reasonable to assume partial rotational fixity for weak axis bena-ing of the attached hanger. The assumption that the tray provides lateral bracing to the frame has not been validated (see Review Issue 18 for a discussion of tray clamps). Cygna believes that it is acceptable to con-sider the effective increase in allowable axial loads based upon a multiple load application. However, the increase is a function of the applied loads, and must be calculated individually for each support configuration and load case.

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6/21/85 Revision 10 Page 9 CABLE TRAY SUPPORTS Review Issues List B. In the design of the compression member for cantilever type supports (e.g., SP-7, Details E, F, G, and H on drawing 2323-El-0601-01-S, etc.) Gibbs & Hill has used the distance from the face of the concrete to the cen-terline of the cable tray as the cantilever length. A value of k = 1.0 was used in calculation of the minor axis slenderness ratio, rather than the actual value of k = 2.0 for cantilevers. A value of k = 1.0 is based on the assumption that the tray will provide lateral Drac-ing at the clamp location (also see Review Issue 18).

C. Gibbs & Hill nas not considered the effect of weld under cut on the section properties of compression members at /hi the point where in-plane braces are attached to the channel web. As shown in the Working Point deviation study (Reference 2), high stresses exist in the region of the brace attachment and may increase if the reduced section properties are considered.

Status: Items A and B are open pending further discussion with Gibbs

& Hill /TUGC0 regarding the systems concept (also see Review Issue 10) and its application to the design of cable tray supports as well as compliance with the AISC specification (also see Review Issue 14) and resolution of the tray clamp adequacy (also see Review Issue 18). Gibbs & Hill should provide technical justification for using the unreduced section properties as described in Item C.

5. Vertical and Transverse Loading on Longitudinal Type Supports

References:

1. Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 2

2. N.H. Williams (Cygna) letter to J.B. George (TUGCO), " Cable Tray Support Review Questions,"

84056.025, dated August 21, 1984, questions 3 and 4

3. R.E. Ballard (Gibbs & Hill) letter to N.H. Williams (Cygna), GTN-69437, dated September 10,1984, with attached calculations E - - ----- Texas Utilities Generating Company

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4. Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 5 Summary: Longitudinal trapeze type supports (e.g., L-Ai , L-A4 , L-C4, etc.) were assumed to act independently of the transverse supports (see Reference 4). Calculations for these longi-tudinal supports (Reference 1) consider only longitudinal loads in the design of frame members and anchor bolts.

Since these supports are rigidly connected to the cable trays with " heavy duty clamps", a tributary tray mass will be associated with these supports. It is Cygna's belief that these supports must be designed for vertical and trans-verse seismic loads as are the transverse supports (References 2 and 3).

Status: Gibbs & Hill should consider these effects and ensure ac-ceptability of this assumption on a generic basis.

6. Support Frame Dead and Inertial Loads

References:

None Sunnary: Gibbs & Hill did not consistently consider support dead loads. Out-of-plane inertial loads were not considered in the design of two-way cable tray supports. Such loads should, as a minimum, be considered in the design of base connections and anchorages. Assuming that tray clamps are able to transmit the loads from the two-way supports to the cable trays, out-of-plane loads must also be considered in the member design of longitudinal supports (also see Review Issue 18).

Status: Gibbs & Hill should provide technical Justification for ignoring dead loads and out-of-plane inertial support loads.

7. Design of Angle lections Neglecting Loading Eccentricity

References:

1. N.H. Williams (Cygna) letter to J.B. George (TUGCO), " Cable Tray Support Review Questions,"

84056.025, dated August 21, 1984, questions 3 and 4 Texas Utilities Generating Company rg'yJkyAj T Comanche Peak Steam Electric Station

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2. N.H. Williams (Cygna) letter to J.B. George (TUGCO), " Cable Tray Support Review Questions,"

84056.027, dated August 27, 1984, question 2

3. AISC 3pecification, 7th Edition, Sections 1.15.2 and 1.18.2.4

4. Gibbs & Hill calculation " Cable tray support type SP-7 with brace. Brace eccentricity calcula-tions." Cygna Technical File 84056.11-1.228

5. Gibbs & Hill calculation " Verify the adequacy of brace L3x3x3/8 of the governing support Case C "

Gibbs & Hill Calculation Binder 2323-SCS-101C,3 Set 1, Revision 1, dated 11/16/84

6. Gibbs & Hill calculation " Justify the use of two L3-1/2x3-1/2x3/8 angles to take the appropriate load and moment individually in the longitudinal tray supports at the lower brace." Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 2, Revision 6, dated 9/15/84 Sunnary: A. Longitudinal cable tray supports typically use angle sections as bracing to resist the longitudinal loads (e.g., SP-7 with brace, L-A 1

, L-A 4

, etc). For the member design, loads were assumed to produce only axial stresses. The induced bending stresses due to eccentric

< end connections were not considered. Neglecting these l flexural stresses can result in members which are under-

! designed. For certain longitudinal supports, double angles are required. The design assumes that the angles l behave as a composite member. However, no intermittent l filler plates are provided as required by AISC Specifi-cation Section 1.18.2.4. Thus, the double angles must be considered to act independently.

B. Transverse and longitudinal cable tray supports typi-cally use angle sections as in-plane braces to resist transverse loads and provide bracing points on the vertical members (e.g.,3A , 4A , 3B , B 4

, L-A4 , etc). For the member design, loads were assumed to produce only axial stresses. The induced bending stresses due to eccentric end conditions were not considered. Tnough it Texas Utilities Generating Company ra 1 ,

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6/21/85 Revision 10 Page 12 CABLE TRAY SUPPORTS Review Issues List is not explicitly stated in the AISC Specifications, it is standard practice (Reference 3, Sheet 3-59) to con-sider the bending stresses due to end connection eccen-tricity and check the interaction ratio considering tne principal axes section moduli.

C. Single longitudinal braces are typically connected to the frame by welding along the legs of the angle. Some brace designs provide welding on only one angle leg at one end of the brace; while, at the other end of the brace, welding is provided on the other angle leg. Such end conditions may lead to failure by twist buckling.

Status: A. Gibbs & Hill pr0vided calculations which considered end eccentricities as well as independent action for each angle in double-angle braces (Reference 6). Case L-B4 was assumed to provide enveloping brace loads. Calcula-tions (Reference 4) were also provided for support type SP-7 with brace, which has a single angle brace. Cygna believes that the approach is acceptable. However, Gibbs & Hill should provide justification for the enve-loping cases.

B. Gibbs & Hill provided a calculation (Reference 5) which considered eccentric load application for in-plane braces. By reviewing the results of the working point deviation study, Gibbs & Hill found that Case C3 had the highest brace loads. See Review Issue 12 for a discus-sion of the working point deviation study.

C. Cygna is presently evaluating the possibility of twist-buckling on single-angle braces.

l l 8. Dynamic Amplification Factors i

References:

1. Gibbs & Hill Report, " Justification of the Equiva-lent Static Load Method Using a Factor of 1.0 Times Peak Spectrum Acceleration for the Design of Cable Tray Supports; Comanche Peak Units 1 and 2."

2. Communications Report between J. Jan (Gibbs & Hill),

G. Bjorkman (Cygna) dated October 4, 1984, 4:00 p.m.

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3. Communications Report between J. Jan, P. Huang, J.

Pier (Gibbs & Hill), N. Williams, G. Bjorkman (Cygna) dated September 13,1984, 3:00 p.m.

4. Communications Report between J. Jan, J. Pier (Gibbs & Hill), G. Bjorkman (Cygna) dated October 12, 1984, 10:00 a.m.

5. Communications Report between J. Jan (Gibbs &

Hill), G. Bjorkman (Cygna) dated October 18, 1984

6. Communications Report between J. Jan, et. al.

(Gibbs & Hill), H. Levin (TERA), R. Kissinger, et.

al. (TUGCO), N. Williams, et. al. (Cygna) dated October 31, 1984 Summary: References 2 through 6 established that 1.14 is an appro-priate dynamic amplification (DAF) factor. The support DAF study was based on continuous, uniformly supported spans.

Current CPSES cable tray support design methodology calcu-lates static loads based on tributary length. Any future

use of the 1.14 support DAF must account for the difference l between the tributary support reactions and the support I reactions based upon continuous cable tray spans. Furtner, it may not be appropriate to use a DAF of 1.14 if supports are designed using non-uniform tributary span length loads.

l l

Status: No further work is required, but this issue should be con-sidered in any evaluation of cumulative effects.

1 1

9. Reduction in Channel Section Properties Due to Clamp Bolt Holes

References:

1. N.H. Williams (Cygna) letter to J.B. George (TUGC0), " Cable Tray and Conduit Support Review Questions," 84056.015, dated August 6, 1984, Attachment B, question 2

2. Gibbs & Hill letter GTN-69371, dated 8/23/84, Calculation SCS-111C, Set 8, Sheets 34-39 Texas Utilities Generating Company F i'/

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. Revision 10 Page 14 CABLE TRAY SUPPORTS Review Issues List Summary: Cygna asked about the reduction in channel section proper-ties due to clamp bolt holes in Reference 1. Gibbs & Hill provided a response in Reference 2.

The response did not to consider the following items:

A. Cable trays may be placed anywhere in the beam span (for example, see CMC 2646).

B. The resolution did not consider cantilevered supports where one tray is close to the wall and other trays are further out.

C. The effect of DCA 17838, which provides bolt hole gage tolerances, is not considered.

D. All unused flange holes are not required to be plug-welded and may be present in high moment regions. (See Note 15 on Gibbs & Hill Drawing 2323-S-0901, Revision 4.)

Status: Gibbs & Hill should provide technical justification for the solutions.

10. System Concept i

References:

1. N.H. Williams (Cygna) letter to J.B. George (TUGCO), " Cable Tray Support Review Questf ons,"

84056.031, dated August 31, 1984, Attachment A, question 2 l

2. L.M. Poppelwell (TUGCO) letter to N.H. Williams

! (Cygna), dated September 28, 1984 with attached l calculations Summary: Gibbs & Hill has assumed that the cable tray and supports l

act as a system. As part of this " systems" approach, the

! following behavior was assumed:

A. For vertical loading, torsion in the beam as well as weak axis bending in the hanger due to the load place-ment eccentricities is taken out by the tray (References l 1 and 2).

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6/21/85 Revision 10 Page 15 CABLE TRAY SUPPORTS Review Issues List B. In the design of trapeze support hanger members for com-pression loads, the trays provide lateral bracing at points along the length of the hanger (also see Review issue 4).

C. The longitudinal and transverse support systems act independently. Therefore, the longitudinal supports are designed for longitudinal loads only, i.e., no trans-verse or vertical load contribution is considered (also see Review Issue 5).

D. Rotation of the base connection angles about the bolt pattern axis is minimzed by the hanger attachment to the tray (also see Review Issue 3).

E. Out-of-plane seismic inertial loads from two-way support frames (self-weight excitation) are resisted by the longitudinal supports (also see Review Issue 6).

F. The cable trays are attached by bolts which are eccen-tric to the weak axis of the beam members. Gibbs & Hill assumed that the effects of the loading were redistri-buted by the tray to other supports.

G. For lortgitudinal supports using composite beams (e.g.,

SP-7 with brace, Detail 8, drawing 2323-S-0903, etc.),

the development of torsion in the beam due to longitu-dinal loading eccentricity is prevented due to cable tray flexure. This tray moment is subsequently balanced by a vertical load coupled between adjacent supports.

Such moment transfer is possible based on the assumption d

that full rotational and translational compatability exists between the cable tray and support beam. The compatability is assumed to be provided by the " heavy duty clamps." (Also see Review Issues 20 and 24.)

Status: Gibbs & Hill should provide justification for the effects due to Items A and F. Items B through G have not been fully b justified considering the hardware. Gibbs & Hill is in the process of completing this qualification. Cygna is con-cerned that Gibbs & Hill's use of a " systems" concept may not be consistent with the actual behavior of the clamps used in the field.

Texas Utilities Generating Company rg Q5*3 Comanche Peak Steam Electric Station L8bJkb- Independent Assessment Program - All Phases 1lllllllllllllllll11lll1111111 Job No. 84056

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11. Validity of NASTRAN Models

References:

1. Gibbs & Hill Calculation Binder 2323-SCS-215C, Sets 2-6

2. Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 3, Sheets 234-243, Revision 9

3. Gibbs & Hill Calculation Binder DMI-13C, Set 1 Summary: Cygna has questioned the validity of the NASTRAN models used in the Gibbs & Hill generic studies, e.g., working point deviation study (Reference 1) and the qualification of Detail Di (References 2 and 3). The models assume a row of one support type, all having identical configuration and I spans. This will influence the system frequencies and seismic response. Such models may not be representative of an actual installation where a mixture of support types and spans is used.

Status: Further Justification is required prior to applying the results of these studies throughout the plant.

12. Working Point Analysis Study I

References:

1. Gibbs & Hill Calculation Binder 2323-SCS-21SC, l

Sets 2-6

(

2. Gibbs & Hill Calculation Binder 2323-SCS-216C,

! Sets 1-5 Summary: A. Gibbs & Hill's working point study (References 1 and 2) does not fully consider the effects of change documen-l tation and previously approved design deviations. Cut-off elevations were established using an assumed cri-tical case of 8'-6" spans, enveloping frame dimensions and maximum permissible working point deviations.

Frames below the cut-off elevations were not checked for compliance with the study parameters. Frames above the cut-off elevation were analyzed on a case-by-case basis but did not consider the effects of change notices. The i

Texas Utilities Generating Company

[eg'{cjlf,] Comanche Peak Steam Electric Station Independent Assessment Program - All Pnases llllllllIl11lllllllllll1llllll Job No. 84056

6/21/85 Revision 10 Page 17 CABLE TRAY SUPPORTS Review Issues List allowable working point deviations resulting trom the study were to be used by QC to a.ccept installed sup-ports. Since changes to any one of the above assumed parameters may effect the acceptability of the study, QC's check of working point deviations alone will not assure support acceptability.

B. The effects of vertical and transverse loads on longi-tudinal support frames were not considered in the work-ing point study (also see Review Issue 5).

C. The portion of the study that evaluated longitudinal supports only checked member interaction. No evaluation was made to ensure that this component governed the design.

D. Modeling Assumptions

1. Instead of modeling a longitudinal support, the ends of the tray run were assumed to be fixed. The effect of this tray boundary condition on the system response was not justified.

2. Tne analysis assumed a single two-foot tray per beam and did not assess the impact of more realistic multiple tray loadings.

3. Eccentricities (also see Review Issue 10).

4. The assumption of tray attachment fixity to the support was not justified.

1

5. Selection of run configuration (also see Review Issue 11).

6. The base engle modeling assumed a simply I

supported Deam for two bolt base connections.

l 7. Excitation in the longitudinal tray direction j was not considered.

l si=== - w Texas Utilities Generating Company r.L'[,q 'i f j Comanche Peak Steam Electric Station

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. Revision 10 Page 18 CABLE TRAY SUPPORTS Review Issues List E. Gibbs & Hill did not check all support components when determining the controlling support element. For exam-ple, support type E4 was assumed to be limited by the load capacity of the Hilti expansion anchors. Cygna's review indicated that the actual governing component was the Richmond Inserts which were not checked by Gibbs &

Hill.

F. Working Point Deviation for Two-Bolt Brace Connection and Longitudinal Trapeze Support Brace.

The working point location does not coincide with the actual line of action of the brace load for two-bolt brace connections, e.g. , Details "F" and "G" on Gibbs &

Hill drawing 2323-S-0903, and the brace concrete connec-tions for support types L-Al through L-A 4, L-8 3, L-B 2.

L-B4 , L-C 1, L-C2 and L-C4 on Gibbs & Hill drawing 2323-S-0902. These offsets may induce larger tensile loads in the anchorages than originally considered in the designs. Additionally, these connections were not evaluated as part of the working point deviation evalua-tion.

Status: To assure support acceptability Gibbs & Hill /TUGC0 should justify the modeling assumptions, the applicability of the analysis results for global support qualification, and the use of working point deviations by QC.

13. Reduced Spectral Accelerations l

References:

1. Gibbs & Hill calculations, " Analysis of Alternate l Detail 1"

2. Gibbs & Hill Calculation Binder SCS-101C, Set 3, Sheet 247, Revision 9 l

l 3. Gibbs & Hill Calculation Binder SCS-21SC, Set 4 l Susanary: For the qualification of the supports discussed below, Gibbs l 5 Hill used reduced spectral accelerations based on a calcu-lated support-tray system frequency l

' Texas Utilities Generating Company i

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. Revision 10 Page 19 CABLE TRAY SUPPORTS Review Issues List A. For the analysis of transverse supports, such as type A which was used in analysis of Alternate Detail 1 (Refer 4 ence 1), a reduced acceleration was used. This accele-ration is based on a calculated frequency which is beyond the spectral peak. The study assumes a tray weight of 35 psf and tray spans of 8'-6". Use of this study's results will not be valid in installations where either of the above parameters have been exceeded with-out considering the effect on frequency.

B. Similarly, for longitudinal supports (e.g., type SP-7 with brace [ Reference 3], L-A1 [ Reference 2], etc.) the frequency will decrease due to tray weights exceeding 35 psf or longitudinal spans exceeding 40'-0". In addi-tion, the frequency calculations for support types L-A4 ,

L-B4 , etc., did not include the effect of the axial frequency of the tray.

Status: Additional discussion between Cygna and Gibbs & Hill is required.

14. Non-Conformance with AISC Specifications

References:

1. AISC Specifications for the Design, Fabrication and Erection of Structural Steel for Buildings, 7th Edition Summary: Gibbs & Hill failed to properly consider the requirements of Reference 1 as discussed below.

A. Unbraced length for axial buckling:

1. Section 1.8.4 requires tnat kl/r < 200.

2. Examples where kl/r limitations were exceeded,

a. See Generic Item 4.

l l

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b. Detail SP-7 and associated supports are checked for buckling, assuming that the tray provides a pinned restraint at the tray attachment point; therefore, k = 1.0. However, since no restraint can be assumed, k = 2 and kl/r > 257 for a 12" tray.

B. Unbraced length for lateral torsinal buckling:

1. Section 1.5.1.4.6a requires that Equation 1.5-7 be used to calculate the allowable bending stress for channels. In the denominator, "1" is the unbraced length of the compression flange.

2. Examples where the specifications were ignored or improperly applied,

a. The working point analyses use 22 ksi for the allowable flexural stress witnout checking Equation 1.5-7. Since the frame heights are on the order of 144", an allowable flexural stress of 15 ksi is calcu-lated by Equation 1.5.7.

! b. Detail SP-7 and similar supports consider "l" to be the distance to the tray centerline and not to tne outside rail where the load is l

applied. Use of the larger distance will result in lower allowable bending stresses.

C. Reduction in section due to bolt holes in flanges per Section 1.10.1 (also see Review issue 9).

D. Lacing of double angle braces (also see Review Issue 7).

E. Eccentric connections - Specification Section 1.15.2.

i

Texas Utilities Generating Company l rL eg'[gq 1LAy j Comanche Peak Steam Electric Station

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1. This section requires that any axial members not meeting at a single working point be designed for the eccentricities.

2. Examples of designs where this specification section applies are the gusset plates used for single angle braces, especially type SP-7 with brace.

Status: Technical justification for not complying with the Code should be provided by TUGCO/Gibbs & Hill.

15. Member Substitution

References:

1. Communications Reports between R.M. Kissinger (TUGCO) and J. Russ (Cygna), dated January 17, 1985, 8:15 a.m. and 3:45 p.m.

Summary: A. Note 9 on Gibbs & Hill Drawing 2323-S-0901, Revision 4, states:

" Structural members shown on drawing numbers 2323-S-900 series may be substituted by one step heavier shape of the same size."

Cygna interprets this note as allowing craft to inter-ct.ange structural shapes, e.g., an MC for a C or vice versa, as long as the substituted shape is heavier than, but of the same depth as the original members. This would allow the use of substitute sections which have lower section moduli. TUGC0 has stated that they inter-pret this note as requiring the craft to stay with the same shape, i.e., a C section can only be substituted by a C section (Reference 1).

-_ Texas Utilities Generating Company Comanche Peak Steam Electric Station

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- Revision 10 Page 22 CABLE TRAY SUPPORTS Review Issues List B. Within Qygna's walkdown scope, support number 6654 (also see Review Issue 20) was reviewed and found to be an example of pygna's concern as discussed above. The design required an MC6x12 and the installed member was a C6x13 which has a smaller section modulus (S = 5.80 in3 for a C6x13 compared to S = 6.24 in3 for an MC6x12).

For the other supports listed in Review Issue 20, the required MC6x12's were substituted with C6x8.2's, a substitution not permitted by this note.

C. Cygna could not locate any documentation which informs engineering where such substitutions are made.

Status: TUGC0/Gibbs & Hill should provide justification of such substitutions and the requirements for documentation of the substitutions.

16. Weld Size Requirements

References:

1. N.H. Williams (Cygna) letter to V. Noonan (USNRC),

" Response to NRC Questions," 83090.023, dated March 8, 1985

2. Communications Report between Chang and Huang (Gibbs & Hill) and Horstman, Russ and Williams (Cygna) dated October 27, 1984

3. Communications Report between Chang and Huang (Gibbs & Hill) and Horstman, Russ and Williams (Cygaa) dated November 13, 1984

4. Communications Report between Chang and Huang (Gibbs & Hill) and J. Russ (Cygna) dated November 17, 1984

5. Communications Report between R. M. Kissinger (TUGCO) and J. Russ (Cygna), dated November 30, 1984

6. N.H. Williams (Cygna) letter to J.B. George (TUGCO), " Cable Tray Support Review Questions,"

84056.041, dated February 12, 1985

=== === Texas Utilities Generating Company r' g'{gaJ'i 7 j Comanche Peak Steam Electric Station A Independent Assessment Program - All Phases 11llll11111llllllllllll111ll11 Job No. 84056

- . . ._-. , t 6/21/85 Revision 10 Page 23 CABLE TRAY SUPPORTS Review Issues List Summary: Cygna has discovered the follcwing problems with the weld designs of cable tray supports.

A. The design drawings are missing the weld details as described in Reference 1, Attachment C.

B. Per discussions with Gibbs & Hill /TUGC0 (References 2, 3, 4 and 5), Cygna has noted that the weld sizes shown on the fabrication drawings differ from those shown on the design drawings and those that were assumed in Gibbs

& Hill calculations.

C. Eccentricities were not considered in weld connections.

1. Detail SP-7 witn brace and similar connections require a partial ,oenetration groove weld at the gusset plate / beam connection. The design calculations did not consider the eccentric load transfer from the brace member. The eccentricity of the brace loads results in a weld stress in excess of 400 ksi.

2. Weld designs for base angle connections never considered the eccentricities of the applied loads from the connecting members.

D. The weld designs did not consider the thickness of the connected parts. Gibbs & Hill's weld designs assumed that the full weld throat would be developed without considering the thickness of the connected member.

E. Gibbs & Hill assumed an incorrect minimum weld length for the beam / hanger base angle connection.

1. Gibbs & Hill assumed a distance of 1-k, where 1 = angle leg width and k = distance from back of angle leg to end of fillet.

2. Because of the radius of the curve at the angle toe, r (approximately equal to one-half the leg thickness), the actual weld length is 1-k-r.

U -

Texas Utilities Generating Company Comanche Peak Steam Electric Station r*b'b'g4ifj

' Jk1 Independent Assessment Program - All Phases l111lllllllllllll11lltlll!m1 l Job No. 84056

6/21/85 Revision 10 Page 24 CABLE TRAY SUPPORTS Review Issues List Status: Items A-D are open pending response to Reference 6. Item E requires discussion with TUGCO.

17. Embedded Plates Design

References:

1. N.H. Williams (Cygna) letter to J.B. George (TUGCO), " Cable Tray Support Review Questions,"

84056.041, dated February 12, 1985, Attachment A, question 1

2. L.M. Poppelwell (TUGCO) letter to N.H. Williams (Cygna) dated April 19, 1984, page 11

3. Communications Report between Williams, Russ and Horstman (Cygna), Kissinger and Keiss (TUGC0) and Bhujang, Huang and Chang (Gibbs & Hill) dated September 15, 1984

4. Communications Report between M. Warner (TUGCO) and N. Williams, J. Minichiello and J. Russ (Cygna) dated February 27, 1985 Summary: Gygna's review of cable tray attachments to embedded plates indicated that the allowables for the embeaded plates may not have included the effects of prying action (Reference 1). Additionally, questions from Qygna's pipe support reviewers and cable tray reviewers on the stiffening re-quirements for embedded plate noment connections elicited conflicting responses from TUGC0 personnel. One response indicated that attachments to embedded plates act as stif-feners for moment connections (Reference 2) while another indicated that any moment attachment must be stiffened or sufficiently analyzed (Reference 3).

Cygna has also noted that cable tray embedded plate designs were not within the tolerances of Gibbs & Hill Specification 2323-SS-30, " Structural Embedments" (Reference 1).

Cygna is also evaluating the lack of attributes for embedded plate inspections on the QC Inspection Report forms as well as the verification procedures for attachment proximity criteria (Reference 4).

r- - - - Texas Utilities Generating Company r' ,g'{,q' 'i f } Comanche Peak Steam Electric Station A

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. Revision 10 Page 25 CABLE TRAY SUPPORTS Review Issues List.

Status: TUGCO/Gibbs & Hill should provide justification for the above items.

18. Tray Clamps

References:

1. Gibbs & Hill Drawing 2323-S. n902, Revision b

2. TUGC0 Drawing TNE-S1-0902-02, ReviLion CP-2

3. Communication Report between T. Keiss (TUGCO) and W. Horstman (Cygna) dateG November 15, 1984 Summary: Two general categories of cable tray clamps are used at CPSES. " Friction" type clamps are installed on transverse type supports (e.g., A1, B 1, SP-7, etc.). These clamps are assumed to provide verticaI anc horizontal transverse load transfer. " Heavy duty" clamps are installed on longitudinal trapeze supports (e.g., L-A1 , L-B 1, etc.), three-way sup-ports (e.g., SP-7 with brace, Detail 8 on drawing 2323-S-0903, etc.), and transverse supports where interferences (e.g., tray splice plates, fittings, etc.) prevent the installation of friction type clamps. Heavy duty clamps are designed to transfer vertical, horizontal, transverse and longitudinal tray loads to the cable tray support beam.

g References 1 and 2, DCA 3464, Revision 23, DCA 6299, Revi-sion 7, and DCA 20331, Revision 0, provide clamp configura-tion details.

In addition to the indicated load transfers between trays and supports, Gibbs & Hill has assured other load transfer mechanisms in order to justify behavioral assumptions made in the support designs. For " friction" type clamps, the following assumptions have been made in order to justify the system concept (clso see Review Issue 10).

e The trays will provide out-of-plan.e bracing to trapeze supports to reduce the b,uckling length of the vertical hanger members ,(al.so see Review Issue 4).

e The trays will provide lateral bracing to the compression flanges of the horizontal beams (also see Review Issue 24).

~ ~

Texas Utilities Generating Company Meil @ Comanche Peak Steam Electric Station lll1mlll111lllll11llll111lll Independent Assessment Program - All Phases Job No. 84056

6/21/85 Revision 10 Page 26 CABLE TRAY SUPPORTS Review Issues List e The trays will provide out-of-plane bracing to supports to prevent frame rotation which would result in increased anchor bolt tensile loads (also see Review Issue 3).

• The cable trays will transter out-of-plane iner-tial loads from transverse supports to longitu-din 61 supports on the same tray run (also see Review Issue 6).

e The development of minor axis bending moment in the beams due to the horizontal eccentricity between the beam neutral axis and the clamp bolt is minimized by a bending moment in the cable tray (also see Review Issue 24).

e For vertical loading, the development of torsion in the beam due to the eccentricity between the clamp location and the beam shear center is pre-vented by flexure of the cable tray. This assumes a full moment fixity between the tray and the support beam (also see Review Issue 24).

All of the above assumptions are applicable to

" heavy duty" type clamps. Other assumptions include:

e The development of torsion due to longi-

- tudinal loads on three-way supports using composite beam sections (e.g., SP-7 with brace, Detail 8 on drawing 2323-S-0903, etc.), is prevented by flexure of the cable tray. This assumes a full moment fixity between tray and support beam (Review Issue 24).

Tne assumptions described above are valid only if the clamps can provide suitatle displacement and rotation compatibility between the tray and support beam. Based on a discussion with TUGC0 (Reference 3), Cygna determined that installation tolerances (Reference 2, DCA 6299, Revision 7, DCA 20331, Revision 0, and CMC 93450, Revision 4) have been adopted which allow gaps between the tray side rails, the support Texas Utilities Generating Company r

'eg'{ga 1J ' F Comanche Peak Steam Electric Station

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6/21/85 Revision 10 Page 27 CABLE TRAY SUPPORTS Review Issues List beam and the tray clamps. In order to provide the assumed compatibility, " friction" type clamps must be cinched suffi-ciently to develop friction between the tray / beam and tray /

clamp interfaces. The existance of gaps will preclude the /hh development of the normal contact force require for fric-tional resistance.

Status: Cygna is currently evaluating the various clamp designs to establish their capability to provide the assumed load transfer.

19. Other Loads in the FSAR Combinations

References:

1. CPSES FSAR, Section 3.8.4.3.3

2. Gibbs & Hill Calculation Binder SCS-103C, Set 1, Sheets 14-19

3. Gibbs & Hill Calculation Binder SCS-103C, Set 2, Sheet 32 Summary: Cygna is concerned that all applicable loadings, as defined in Reference 1, are considered in the design of cable tray supports. Among these concerns are LOCA loads. Reference 2 provides the calculations for Detail "A" (Gibbs & Hill drawing 2323-El-0500-01-S), which was originally designed for use in containment. Only dead weight and seismic loads were considered in this design. Similarly, Reference 3 is the design calculation for Detail "C" (Gibbs & Hill drawing 2323-El-0500-04-S). This support was only evaluated for dead weight and seismic loads.

Status: Discussion with Gibbs & Hill /TUGC0 is required to establish the exact criteria for not specifically evaluating other possible support loadings.

20. Differences Between the Installation and the Design / Construction Drawings without Appropriate Documentation

References:

1. Gibbs & Hill, Inc., support layout drawing 2323-El-0713-01-S Texas Utilities Generating Company r 1 Comanche Peak Steam Electric Station

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2. Brown & Root, Inc., fabrication drawing FSE-00159

3. American Institute of Steel Construction, Inc.,

Manual of Steel Construction, 7th Edition

4. Gibbs & Hill support layout drawing 2323-El-0601-01-S

5. Gibbs & Hill support layout drawing 2323-El-0700-01-S

6. Gibbs & Hill cable tray support design drawings 2323-S-0900 series

7. N.H. Williams (Cygna) letter to J.B. George (TUGCO), " Cable Tray Support Walkdown Questions,"

84056.026, dated August 23, 1984

8. Communication Report between M. Warner, J. van Amerongen (TUGCO) and W. Horstman (Cygna) dated October 25, 1984

9. Communication Report between T. Webb, M. Hamburg (TUGC0) and W. Horstman (Cygna) dated October 18, 1984

10. Communication Report between M. Warner, C. Biggs (TUGCO) and W. Horstman (Cygna) dated October 10, g

1984

11. Brown & Root Procedure No. CEI-20, Revision 9,

" Installation of Hilti Drilled-In Bolts"

12. L.M. Popplewell (TUGCO) letter to N.H. Williams (Cygna), " Comanche Peak Steam Electric Station Cygna Review Questions," dated September 6,1984

13. N.H. Williams (Cygna) lette.- to J.B. George (TUGCO), " Cable Tray Support Walkdown Questions,"

84056.021, dated August 16, 1984 Susanary: Cygna performed walkdown inspections on 49 of the 92 sup-ports within the review scope. Certain discrepancies be-tween the as-built support configurations and the design requirements were as noted below.

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; Texas Utilities Generating Company r4 y'ifj Comanche Peak Steam Electric Station

' J A Independent Assessment Program - All Phases 1lll11lll11llll1lll11111ll1111 Job No. 84056

6/21/85 Revision 10 Page 29 CABLE TRAY SUPPORTS Review Issues List A. Support No. 481, Longitudinal Type A4 Single angles were installed as braces in the longitu-dinal direction. A pair of angles is required by the design drawing. No change documentation was located.

B. Support No. 408, Type B4 The lower corner of the frame is modified by CMC 9916, Revision 1, to avoid interference with the CCW heat ex-changer. This change document shows that 4" channel sections are to be used for the prescribed modification.

A 6" channel section is actually installed.

C. Support No. 649 Type Al This installation uses concrete anchorage " Alternate Detail 1" (Gibbs & Hill design drawing 2323-S-0903) which requires the use of an L6x6x3/4. Cygna's field inspection discovered that an L5x5x3/4 was installed. No existing documentation accounted for this discrepancy.

D. Support Nos. 722 and 2606, Detail "N", Drawing 2323-El-0601-01-S Cygna's field inspection found a working point violation on the brace attachment to the wall. Design drawing 2323-S-0929 Connection Detail "F" was used (2323-S-0903) which has a tolerance of' b/2

• 0.3b where 12"<b(30".

Cygna's field inspection results show the tolerance used was b/2- 0.5b (i.e., the brace was located in line with one bolt).

"*'- Texas Utilities Generating Company r Comanche Peak Steam Electric Station

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,,,,, ,,,1 l [ j Independent Assessment Program - All Pnases nununninnilllilllllill Job No. 84056

6/21/85 Revision 10 Page 30 CABLE TRAY SUPPORTS Review Issues List E. Support Nos. 2992, 2994, 300b, 3017, 3021, 6654, Type A2 Reference 1 identified the above six supports as follows: "A where L = 8'23$except(frame all members width), h = 4'-2"shall be MC6x12),"

(frame height).

The Cygna walkdewn documented the installed hanger member sizes, as listed below in Table 1. Due to the presence of "hermolag coating, Cygna was unable to determine the installed beam member size. No documenta-tion existed to reconcile the differences between the design requirements and the installation.

TABLE 1 Cable Tray Support Member Sizes Dimensions (See Note 1) Member Size Flange Support Depth Width Existing No. (In) (In) (Note 1) 2992 6 1-7/8 C6 x 8.2 2994 6 1-7/8 C6 x 8.2 3005 6 1-7/8 C6 x 8.2 3017 6 1-7/8 C6 x 8.2 3021 6 1-7/8 C6 x 8.2 6654 6 2-1/8 C6 x 13

! Note: 1. Dimensions of the vertical channels are based on measurements by Cygna.

l Member sizes are determined by selecting the channel type from Reference 3 which most closelj matches the measured depth and flange width.

t h

1 Texas Utilities Generating Company r*h*[*j lfl l L i Comanche Peak Steam Electric Station

! ll1111lllll1ll11111111lllll111 Independent Assessment Program - All Phases Job No. 84056

1 6/21/85 Revision 10 Page 31 CABLE TRAY SUPPORTS Review Issues List F. Support No. 455, Type SP-8 Cygna's field inspection indicated that the brace con-nected to the wall on one side of the support is located outside of the bolt pattern on the base angle. The Detail "B" (2323-S-0903) type connection requires a tolerance of b/2

• 0.2b. In response to Cygna's ques-tion, TUGC0 issued CMC 99307, Revision 0, to document this discrepancy.

G. Support Nos. 2998 and 13080, Special Type Supports These supports were installed in floor slabs with 2" .

topping. The topping depth was apparently not consid-ered in selecting the length of the anchor bolt. There-fore, the required embedment length was not achieved.

H. Hilti Super-Kwik Bolts Without Stars Section 3.1.3.1 of Brown & Root Procedure CEI-20 (Reference 11) requires:

Hilti Super Kwik-bolts shall be additionally marked with a " star" on the end which will remain exposed upon installation.

Twenty-eight of the cable tray supports inspected by l Cygna required the installation of Hilti Super Kwik-l bolts, of these, only two supports had stars stamped on I the bolts. The bolts on the remaining supports were not stamped. /hi l I. Contact Between the Component Cooling Water (CCW) Heat l Exchanger and Cable Tray Support Nos. 332 and 408 Gibbs & Hill specification 2323-ES-100 requires a clear i distance of six inches between cable tray supports and l Class 1 piping including insulation unless otherwise allowed by the Owner. Cygna's walkdown noted that cable tray support numbers 332 and 408 were in contact with

! the CCW heat exchanger (Reference 13). Documentation j did not exist which allowed this situation.

l

! -- Texas Utilities Generating Company F"-k'l',2 i 7 A1 Comanche Peak Steam Electric Station L Ji Independent Assessment Program - All Phases illlillllllillllllllillllillli Job No. 84056

6/21/85 Revision 10 Page 32 CABLE TRAY SUPPORTS Review Issues List Status: A. TUGC0 provided CMC 2635, Revision 1, to document the installation discrepancy for support number 481.

B. TUGC0 provided CMC 9916, Revision 2, tc document the installation discrepancy for support number 408.

C. TUGC0 provided CMC 99308, Revision 0, to document the installation of the incorrect size base angle for sup-port number 649.

D. TUGC0 provided CMC 99309, Revision 0, to document the anchor bolt installation discrepancy for these two supports.

E. TUGC0 provided the CMC's listed below to document the installation of the incorrect member sizes.

Support Number CMC No. Revi~sion 2992 44519 9 2994 99326 0 3005 96079 1 3017 99327 0 3021 30452 2 6654 90714 6 F. TUGC0 provided CMC 99307, Revision 0, to document the installation discrepancy for support number 455.

G. TUGC0 is to evaluate the effect of reduced embedment length for supports 2998 and 13080. Cygna is evaluating the action required by SDAR 80-05 for supports installed after its issuance.

Texas Utilities Generating Company r.g g,q i f } Comanche Peak Steam Electric Station

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. Revision 10 Page 33 CABLE TRAY SUPPORTS Review Issues List H. Cygna has discussed the absence of stars on Hilti Super Kwik-bolts (References 10 and 12) witn TUGCO. The lack of stars is attributable to the procedures in place at the tine of support installation (Reference 12). To verify that Hilti Super Kwik-bolts were installed per the design drawings, Cygna witnessed the ultrasonic testing (UT) of several supports (Reference 9). A total of twenty-one supports were tested. All expansion /hi anchor bolts were verified to be Hilti Super Kwik-bolts as required.

I. TUGC0 issued CMC 1887, Revision 1 and CMC 9916, Revision 4 for support numbers 332 and 408, respectively. These CMCs specified support modifications to assure that a minimum clearance of 1" was provided between the CCW heat exchanger and the cable tray supports.

21. Design Control

References:

1. Gibbs & Hill Drawings 2323-El-0601-01-S, 2323-El-0700-01-S, 2323-El-0713-01-S

2. N.H. Williams (Cygna) letter to J.B. George (TUGCO), " Cable Tray Support Design Review Ques-tions," 84056.022, dated August 17, 1984, ques-tions 1, 2, and 6

3. N.H. Williams (Cygna) letter to J.B. George (TUGCO), " Cable Tray Support Design Review Questions," 84056.025, dated August 21, 1984, question 1

4. Gibbs & Hill Cable Tray Support Design Drawings 2323-S-0900 Series

5. Gibbs & Hill Calculations for Support Numbers 3025, 3028, 2861, Cygna Technical File 84056.11.1.225

6. L.M. Poppelwell (TUGCO) letter to N.H. Williams

< (Cygna), " Responses to Cygna Review Questions,"

dated September 4,1984, with attached calcula-tions s

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7. Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 3, Sheets 206, Revision 6

8. L.M. Poppelwell (TUGCO) letter to N.H. Williams (Cygna), " Response to Cygna Design Review Ques-tions," dated September 11, 1984, with attached .

calculations

9. Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 5

10. Gibbs & Hill Drawing 2323-S-0901, Revision 4

11. N.H. Williams (Cygna) letter to J.B. George (TUGCO), " Cable Tray Support and Electrical Review Questions," 84056.019, dated August 10, 1984, questions 2.1 and 2.2

12. Gibbs & Hill Drawings 2323-El-0601-01-S, 2323-El-0700-01-S, and 2323-El-0713-01-S Summary: A. Lack of consideration of tne effects of generic CMC's, 2hs DCA's and installation specifications on the original designs:

1. Support type SP-7 with brace is affected by CMC 6187. The CVC was approved and design reviewed by Gibbs & Hill, New York, but its effects were not considered in the SP-7 with brace calculations or any generic reviews.

2. The effect of CMC 1970, which specifies the allowable edge distance for anchor bolt holes in base angles, was not considered in the design of the anchor bolts.

3. Gibbs & Hill installation specification 2323-SS-16b allows a tolerance of 2* for member A 2

plumbness. The effects of this tolerance were not considered in the support designs.

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6/21/85 Revision 10 Page 35 CABLE TRAY SUPPORTS Review Issues List B. Criteria violations in individual support specifications on support plans:

In the generic design of cable tray supports, support dimension and loading limitations are determined for each support type. These limitations are typically stated in the design calculations, but are not shown on the generic support design drawings (Reference 4). The dimensions for each support are specified in a descrip-tive block on the support plans (Reference 1) and the loading is indicated by the supported tray width shown.

The tray supports listed below were identified as having loadings or support geometries which exceeded the design limitations. Prior to the Cygna review, Justifying documentation did not exist for these individual support designs.

1. Support Nos. 302b, 3028, 2861, Type 01 .

Drawing 2323-El-0713-01-S calls out these supports as type 0 16.3), L = 11'-9",1h(except

= 4'-2",beam to beaMC6 and shows tray x width of 78". The FSE-00159 fabrication drawing sheets reflect these dimensions. How-ever, the Gibbs & Hill design calculations for Type Di supports (2323-S-0901) limit L < 8'-0" and tray width to 48".

t 2. Support No. 2607, Type A1 . Drawing 2323-El-0601-01-S specifies dimensions of L = 2'-9" and h = 4'-6" for this support. The design calculation for this support type (S-0901)

! limits h < 2'-4".

3. Support No. 657, Type A1 . Drawing 2323-El-0601-01 calls out this support as Type A1 , L =

7 ' -0" , h = 2' -0" . The design calculation for this support type limits L < 6'-0".

4. Support No. 734, Detail H, Urawing 2323-El-0601-01-S. This drawing specifies that one beam is to be an MC6x15.1, rotated 90' from its normal orientation. The support design requires the use of C6x8.2 beam sections. CMC Texas Utilities Generating Company

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6/21/85 Revision 10 Page 36 CABLE TRAY SUPPORTS Review Issues List 00164 requires the use of " heavy duty clamps" for this support, which introduce longitudinal loads. The support design requires the addi-tion of a longitudinal brace if longitudinal loads are to be resisted.

5. Support No. 3011, Type SP-6. Urawing 2323-El-0713-01-S specifies dimensions of L = 8'-9" and h = 4'-6". The design calculation for this support type limits L < 6'-0".

6. Support Nos. 2992, 2994, 3005, 3017, 3021, 3111, 66b4, Type A2 . Drawing 2323-El-0713 S specifies dimensions of L = 8'-3" and h =

4'-2", and shows. a tray width of 78". The design calculation for this support type limits L < 6'-0" and the tray width to 48".

Additionally, Gibbs & Hill has support designs wherein the controlling criteria (i.e., support dimensions, tray width, etc.) have not been ad-hered to. As an example, the support frame was designed for a particular height and width while g

the anchorages were designed for another height and width. The lack of a single limiting configu-ration affects the support specifications as shown on the cable tray support plans. Within Cygna's scope, support types E4 and SP-6 are affected.

C. Consideration of as-built support conditions in generic reviews which require a case-by-case review:

1. The SP-7 weld underrun analysis considered 5/16" fillet welds wnicn are specified on the design drawings. However, the FSE-00159 fabrication drawings specify smaller weld sizes. In addition, the underrun analysis did not consider the effects of any design changes s to the supports which were reported in CMC's and DCA's.

2. Working point studies (also see Review Issue 12).

- Texas Utilities Generating Company

[T. [.d [ M Comanche Peak Steam Electric Station Independent Assessment Program - All Phases 1:::::::::::":'lllllllllltll Job No. 84056

6/21/85 Revision 10 Page 37 CABLE TRAY SUPPORTS Review Issues List D. Inconsistent application of as-built and design infor-mation in the evaluation of cable tray supports for Thermolag application:

1. Tray cover weights were not included in tne development of the allouable span length table (Procedure CP-El-4.0-49).

2. Cygna believes that longitudinal supports are not evaluated for the added weight of fire protection. Evidence of the above includes the fire protection review for the tray run containing Detail "N" (Gibbs & Hill Drawing 2323-El-0601-02-S) which did not note the lack of any longitudinal supports in the tray run.

3. Fire protection evaluations are performed on a tray-by-tray basis. The cumulative effect of multiple trays with fire protection on one support may not be considered.

E. Tray span between supports used in the original support layout:

1. Reference 9 indicates that cable tray supports are to be designed for 8'-0" spans. Reference 10, Note 13, allows a location tolerance for supports of i 1/2 Richmond Insert spacing parallel to the tray, and limits the maximum spacing between supports to 9'-0." Gibbs &

Hill cable tray support design calculations assume a maximum tributary span of 8'-6," to account for a support spacing of 8'-0" on center and an erection tolerance of i 6."

Cygna reviewed Reference 12 and noted 14 locations where the as-designed tray spans exceeded 8'-0." Cygna's walkdown of these tray segments discovered five locations where the as-built tray Spans exceeded 9'-0" (see Reference 11). This indicates that the design and installation limitations for support spacings were not adhered to.

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2. Longitudinal support designs indicate that the maximum longitudinal tray span is 40'-0". For several supports within Cygna's review, the support plan drawings (Reference 12) specified these supports to have tributary spans greater than 40'-0" (see Reference 11). In addition, several horizontal tray segments were not provided with longitudinal supports (see Reference 11). This indicates that the design limitations for the location of longitudinal supports were not adhered to.

F. Use of "For Reference Only" Calculations:

Cygna has noted several design reviews of change notices where the CVC was marked to Indicate that new or revised calculations were not required. However, attached to the CMC are calculations that are marked "For Reference Only".

G. Cygna is concerned about support design calculation retrievability and completeness.

H. Lack of Controlled Design Criteria:

1. Cygna has noted instances where the field design review group did not utilize the proper criteria to evaluate support adequacy. The evaluations for fire protection compared the actual load to a design load based upon a 9'-

0" tributary tray span. The maximum tributary span assumed in the current design is 8'-6".

2. Cygna has asked what supplements to the 7th Edition of AISC Specifications were committed to in the FSAR. No evidence was found to indicate that proper direction was given to design engineers to utilize the requirements of any supplements to which CPSES was commit-ted. ,

Status: A. No further discussion is required.

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6/21/85 Revision 10 Page 39 CABLE TRAY SUPPORTS Review Issues List B. Gibbs & Hill has indicated that the engineer preparing a support layout drawing would be familiar with the design limitations. Based upon engineerin9 Judgement, these limitations could be exceeded without preparing support-ing calculations, since the-support map drawings would be subject to design review. Gibbs & Hill should assure that the critical frame limitations have not been ex-ceeded without proper technical justification.

For the individual' supports referenced above:

(1) Gibbs & Hill provided calculations (Reference

5) evaluating these supports. Support num-bers 3025 and 3028 were found acceptable, support number 2861 shows 30% overload of anchor bolts.

(2) TUGC0 provided calculations (Reference 6) demonstrating the acceptability of support number 2607.

(3) TUGC0 provided calculations (Reference 6) demonstrating the acceptability of support number 657.

(4) Gibbs & Hill /TUGC0 have not provided a re-sponse.

(5) Gibbs & Hill provided calculations (Reference

7) demonstrating the acceptability of support number 3011.

(6) TUGC0 provided calculations (Reference 8) demonstrating the acceptability of these supports.

C. No further discussion is required.

D. Cygna is continuing internal evaluation.

E. Gibbs & Hill has indicated that the engineer preparing a support map drawing would be familiar with the span limitations for transverse and longitudinal supports.

Based upon engineering judgement, these limitations Texas Utilities Generating Company r *I'(pJ - air L f i} Comanche Peak Steam Electric Station L Independent Assessment Program - All Phases lllllllll1lll1111111111I11ll11 Job No. 84056

D 6/21/85 Revision 10 Page 40 CABLE TRAY SUPPORTS Review Issues List could be exceeded without preparing supporting calcula-tions, since the support map drawings would be subject to design review.

For the individual span violations noted above,

1. Gibbs & Hill /TUGC0 provided calculations qualifying trays and supports for the transverse span violations.

2. Gibbs & Hill /TUGC0 provided calculations qualifying trays and supports for the indicated longitudinal span violations.

For tray segments lacking longitudinal supports, the load was applied as addi-tional transverse loads on transverse type supports located around a 90 bend from the unsupported tray segment. For one tray run without any existing mecha-nism to resist longitudinal loads, seg-ments T120SBC25 and T130SCA45, the addition of a new longitudinal support was required.

F. Cygna is continuing internal evaluation.

G. Cygna is continuing internal evaluation.

H. Cygna is continuing internal evaluation.

22. Design of Support No. 3136, Detail "5," Drawing 2323-S-0905

Reference:

1. Gibbs & Hill Calculation Binder SAB-1341, Set 3

2. Communication Report between B.K. Bhujang (Gibbs &

Hill) and N. Williams, et al. (Cygna) dated October 20, 1984

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Independent Assessment Program - All Phases h..,11llllll Job No. 84056

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• Revision 10 Page 41 CABLE TRAY SUPPORTS Review Issues List Susunary: Support No. 3136, located at elevation 790'-6" at the Auxil-iary Building / Safeguards Building boundary, is embedded in a fire wall. In reviewing the calculations, (Reference 1) for the design of this support, Cygna located several possible discrepancies. A list of Cygna's questions was provided (Reference 2, Attachment A) to Gibbs & Hill for tneir re-view.

Status: Gibbs & Hill /TUGC0 should provide a response to Cy9na's concerns.

23. Load Placement In STRESS Models

Reference:

1. Gibbs & Hill Computer Output Binder DMI-SP Sununary: For the design of standard support cases Aj, Bj, C4 and Dj, where i = 1 to 4, finite element analyses were performed (Reference 1) using the program STRESS. Single elements were used to model the horizontal members (beams) and the vertical members (hangers). Tray loads were applied at the beam / hanger intersection rather than within the span of the beam where the tray is physically located.

Modelling the load placements in this fashion eliminates the effects of bending and torsion due to vertical loads on the beams, and for cases Dj, will totally remove the load from the support.

Since support cases A1 , B 2 B1 > B2, C1 and C2 are unbraced frames, they have not been explicitly reevaluated by Gibbs &

Hill in the Working Point Deviation Study or similar, more refined analyses.

Status: Gibbs & Hill to provide Justification for the adequacy of these support cases.

24. Design of Flexural Meqars

Reference:

1. N.H. Williams (Cygna) letter to J.B. George (TUGCO), " Cable Tray Support Review Questions,"

84056.031, dated August 31, 1984 Texas Utilities Generating Company 3d[ Q 11lllllll1111lll11lllllllllll1 Comanche Peak Steam Electric Station Independent Assessment Program - All Phases Job No. 84056

6/21/85 Revision 10 Page 42 CABLE TRAY SUPPORTS Review Issues List

2. L.M. Popplewell (TUGCO) letter to N.H. Williams (Cygna) " Comanche Peak Steam Electric Station Cygna Review Questions," dated September 28, 1984

3. Communication Report between E. Bezkor et al.

(Gibbs & Hill) and M. Engleman et al. (Cygna) dated April 11, 1985 Summary: In the design of cable tray support flexural members (i.e.,

beams) Gibbs & Hill did not consider several important items as discussed below.

A. Additional major axis bending stresses due to transverse loads are introduced by the vertical eccentricity be-tween the cable tray centerlines and the beam neutral axis (Reference 1). Gibbs & Hill provided calculations (Reference 2) indicating that the increase in bending stress did not exceed 2.5% of the allowable stress level. The analysis assumed that the beam was a fixed-fixed member, effectively isolating it from the re- /hi mainder of the support structure. In addition, the load transfer mechanism that was assumed provided by the tray clamps did not address the transfer mechanisms inherent in other clamp configurations (also see Review Issue 18).

B. Minor axis bending of the beams due to transverse load-ing is introduced by the horizontal eccentricity between the beam neutral axis and the location of the tray clamp bolt holes in the beam's top flange (Reference 1).

Gibbs & Hill's response (Reference 2) did not consider the allowed tolerance in bolt hole gage per DCA 17838, Revision 8. A load transfer mechanism was assumed to be provided by the clamp which will allow the trays and supports to act as a system, resulting in increased transverse loads on adjacent supports and no minor axis flexure in the beams (also see Review Issue 10).

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6/21/85 Revision 10 Page 43 CABLE TRAY SUPPORTS Review Issues List C. Vertical loading introduces torsion into the beams due to the horizontal offset between the tray clamp location and the shear center of the beam. In Gibbs & Hill's response (Reference 2), the torsional moment was signi-ficantly reduced based on an assumed moment resistance provided by the tray clamps and the tray / support system concept (also see Review Issue 10).

D. Torsion is introduced into the beam by longitudinal loading due to:

1. The vertical offset between the tray center-line and the beam shear center (for longitu-dinal trapeze type supports, e.g., L-A1 ,

L-B1 ).

2. The vertical offset between the tray center-line and the shear center of the composite beam (for longitudinal supports similar to SP-7 with brace, Detail 8, drawing 2323-S-0903, etc.,

A Gibbs & Hill's evaluation of the torsional effects are included in Reference 2. The evaluation of torsion due to loading type 1 only considers the eccentricity be-tween the shear center and the top of the tray rungs for ladder type trays or the tray bottom for trough type trays. The centroid of the tray fill is a more appro-priate location from which to calculate the eccentri-city. For loading type 2, the longitudinal load is applied at the bottom of the tray side rails, rather than the centroid of the tray fill. The tray clamps are assumed to provide rotational restraint to the top flange of the composite beam, and all torsional moments are assumed to be resisted by a couple formed between adjacent vertical supports through flexure of the cable tray (also see Review Issues 10 and 18).

E. Gibbs & Hill has not consistently considered the reduc-tion in the beam section properties due to bolt holes through the flanges (also see Review issue 9) and weld undercut effects. Based on CMC 68338, Revision 0, the welded connection between the beam and hanger can in-clude vertical fillet welds crossing the web of the

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Page 44 CABLE TRAY SUPPORTS Review Issues List beam, thus weld undercut would effect the beam capacity at this cirtical location. In addition, based on the tray installation tolerances provided in Gibbs & Hill specification 2323-ES-100, Section 2.28 and the effect of CMC 2646, Revision 5, the tray clamp can be located such that the bolt hole is in the same cross-sectional plane as the effective weld undercut. Tnas, it is possible that both reductions may occur simultaneously.

F. Gibbs & Hill has not evaluated the effects of shear stresses on beam acceptability. Shear stresses will be introduced by two loadings:

1. Direct shear due to applied forces; and,

2. St. Venant shear associated with torsional loads (see Items C and D above). Cygna's review indicates that direct shear stresses are minor and generally do not govern the design of flexural members. When these d

stresses are considered in combination with the potentially large St. Venant shear stresses, the effect can be a significant factor in the member design (Reference 3).

G. Gibbs & Hill generally assumes an allowable major axis bending stress of 22 ksi for beam designs. The capacity reduction based on the unsupported length of the beam's compression flange (AISC Equation 1.5-7) is not consid-ered (also see Review Issue 14). Justification is pro-vided based on the assumption that the tray and tray clamp will provide lateral bracing to the compression i flange. This assumption is dependent on the tray clamp's ability to provide bracing (also see Review Issue 18) and neglects the possibility of bottom flange being in compression due to support frame sidesway and seismic uplift.

Status: A. Gibbs & Hill should provide technical justification for the assumed load transfer mechanism provided by the tray clamps and the fixed end conditions used in the evalua-tion of the increased major axis bending.

B. For status, see Review Issue 10.

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6/21/85 Revision 10 Page 45 CABLE TRAY SUPPORTS Review Issues List C. For status, see Review Issue 10.

D. Gibbs & Hill should provide justification for the as-sumed location of the applied longitudinal load, the assumed behavior of the tray clamps and the system concept. (See also status for Review Issues 10 and 18.)

E. Gibbs & Hill hsould provide technical justification of jg the beam adequacy considering weld undercut and bolt hole section reductions occurring at the same location.

(See also Review Issue 9.)

F. Gibbs 3 :lill should provide technical justification that the combined direct and St. Venant shear stresses are at an acceptable level.

G. The outcome of this issue is dependant on resolution of Review Issues 14 and 18.

25. Cable Tray Qualification

References:

1. Gibbs & Hill Specification 2323-ES-19, Revision 1

2. Gibbs & Hill Structural Calculation 2323-SCS-111C, Set 7, Revision 1

3. T.J. Cope, Test Report and Calculations for the Qualification of Cable Trays

4. CPSES FSAR, Section 3.10B.3, Amendment 44

5. Gibbs & Hill Specification 2323-ES-100, Revision 2 2h

6. IEEE " Recommended Practices for Seismic Qualification of Class 1E Equipment for Nuclear Power Generating Stations," STD 344-1975

. 7. CPSES FSAR Section 3.78.2.1.3

8. Gibbs & Hill Drawing 2323-S-0901, Revision 4

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9. L.M. Popplewell (TUGCO) letter to N.H. Williams (Cygna), " Response to Cygna Review Question 2.1 of Letter 84056.019," dated August 27, 1984 with attached calculations Summary: The qualification requirements for cable trays are outlined in References 1 and 4. In reviewing related specifications, calculations, and installations of cable trays, Cygna has noted several areas of concern.

A. Qualification of cable trays is performed through static load testing and calculation of loading interactions for dead load plus three components of seismic load (Reference 1, Section 3.9 and Reference 3). Seismic loads are calculated by the equivalent static load method, using total tray dead weight times the peak spectral acceleration. No apparent dynamic amplification factor (DAF) is used.

Reference 6, Section 5.3, ana Refcrence 7, recommend the use of a DAF = 1.5 unless justification is provided.

B. The interaction equation specified for checking cable tray jQg capacity (Reference 1, Section 3.9.4) is limited in its application, and may have been used incorrectly.

The testing and qualification of cable trays is based on an 8'-0" simply supported tray span, References 1 and 3, yet Reference 8, Note 13, allows a support installation tolerance resulting in a maximum tray span of 9'-0" for Unit 1.

The capacity values derived in the tr sy testing are total uniform loads (in lbs) for an 8'-0" section of cable tray (Reference 3). These values, F , Ft and F , as used witn the interaction equation are on y applicab e to qualifying tray sections with 8'-0" spans. However, for tne fire protection evaluation calculations (Reference 2) and tray span violation calculations (Reference 9) total loads for various tray spans were calculated as f' = w

• 1, where w is

. the tray unit weight and 1 is the tray span. This load was compared with the rated tray capacity using the interaction equation.

For evaluation of trays with spans other than 8'-0", a capacity comparison must be made in terms of trav bendino

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, Revision 10 Page 47 CABLE TRAY SUPPORT 3 Review Issues List moaent wnich is proportional to w

• 1, 2 rather than the total load on the tray section. For example, if an 8'-0" tray span will support a total distributed load of 1600 lbs (200 lb/ft) by increasing the span to 10'-0", a uniform load of 128 lb/ft (1280 lbs) would result in the same bending moment at mid span. Therefore, the capacity for the 10'-O" span would be 1280 lbs and not the 1600 lbs assumed.

C. Cygna has noted several instances of modifications to cable tray hardware without adequate justification or documentation.

1. Tray Segment No. 130SCA46 is assumed to be a 24"x6" ladder-typ tray in the fire protection evaluation calculations for Safeguards Building Elevation 790'-6". Cygna's walkdown indicates that this tray is actually a 24"x4" ladder-type tray with 6" side rail extensions added to increase the tray depth. Tne tray qualification test report (Reference 3) does not provide qualification for trays using side rail extensions. Cygre.'s concerns include the ability /hg of these extensich5 to resist bending moments, the shear flow through the connection bolts, and the effect of the reduction in tray side rail section properties due to the bolt holes used to attach the side rail extensions.

2. Tray Segment T120SBC35 is joined to a tray reducer with side rail splice connector plates. These plates have been modified by removing portions of their bottom flanges such that only the web area remains. This connector will not satisfy the requirements of Reference 1, Section 3.7, Paragraph f, which states that connectors "shall have moment and shear strengths at least equal to those of the continuous uncut side rail." Cygna was unable to locate documentation justifying this modification of vendor supplied hardware.

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, Revision 10 Page 48 CABLE TRAY SUPPORTS Review Issues List D. Cable tray section properties are calculated based on the test results (Reference 3). The moment of inertia is calculated based on the flexural displacement formula. For horizontal transverse loading (i.e., in the plane of the rungs) ladder-type cable trays show a truss-like behavior, and the deflection will be due to both flexure and shear deformations.

This will effect the calculated moment of inertia as used in any Gibbs & Hill analyses which consider the tray properties for frequency or displacement calculations.

. Status: jg A. Gibbs & Hill should provide justification for the DAF used for tray evaluation.

B. Gibbs & Hill should provide justification for the use of the tray capacity interaction equation.

C. Gibbs & Hill /TUGC0 should provide documentation illustrating the acceptability of the use of tray side rail extensions and modifications to tray connector plates.

D. Gibbs & Hill should provide justification for the use of the flexural deflection formula for the calculation of the cable tray moments of inertia.

\

Texas utilities Generating Company g [ , Comanche Peak Steam Electric Station g-" Independent Assessment Program - All Phases Job No. 84056

• 6/21/85 Revision 1 Page 1 DESIGN CONTROL Review Issues List

1. Review and Analysis of Cumulative Effects

References:

1. Cygna Phase 1 and 2 Final Report, TR-83090-01, Revision 0, all Sections

2. Cygna Phase 3 Final Report, TR-84042-01, Revision 1, all Sections

3. N. H. Williams (Cygna) letter to V. Noonan (USNRC), "Open Items Associated with Walsh/Doyle Allegations," 84042.022, dated January 18, 1985

4. N. H. Williams (Cygna) letter to V. Noonan (USNRC), " Status of IAP Conclusions," 84056.050, dated January 25, 1985

5. All Communications Reports and correspondence written on all Phases of the Independent Assess-ment Program Summary: Utilizing the data available from all four phases of the Cygna technical and design control reviews, a cumulative effects evaluation of all observations and potential finding reports is being performed. This review is also focusing on the cumulative effects of individually insignificant discre-pancies. Any trends identified which indicate either strengths or weaknesses in the CPSES design / design control program are being evaluated.

Status: Gygna is in the process of extracting raw data from all phases of the IAP performed to date. The results of this review will be included in the Phase 4 Final Report.

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2. Adequacy of the Design Process used on CPSES

References:

1. Memorandum and Order (Quality Assurance for Design), Texas Utilities Generating Company, et al., Comanche Peak Steam Electric Station Units 1 and 2, dated December 28, 1983

2. CASE's Motion for Summary Disposition, "Allega-tions Concerning Quality Assurance Program for Design of Piping and Pipe Supports," dated July 3, 1984

3. Cygna Phase 1 and 2 Final Report, TR-83090-01, Revision 0, all Sections

4. Cygna Phase 3 Final Report, TR-84042-01, Revision 1, all Sections

5. N.H. Williams (Cygna) letter to V. Noonan (USNRC), " Status of IAP Conclusions," 84056.050, dated January 25, 1985

6. All Communications Reports and correspondence written on all Phases of the Independent Assessment Program Summary: Based on tne Phase 1 through 4 review scopes, Cygna is evaluating the adequacy of the process employed in the design of Comanche Peak Steam Electric Station. This review also includes an assessment of the resulting qualitj of tne final design.

Status: This evaluation is ongoing in conjunction with the cumula-tive effects review. The results of this review will be included in the Phase 4 Final Report.

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