ML20092C780

Rev 1, Shroud & Shroud Repair Hardware Analysis Volume:1, Shroud Repair Hardware Backup Calculations

ML20092C780
Person / Time
Site:	Dresden
Issue date:	05/12/1995
From:	Kaul M, Wu M, Zaliznyak S GENERAL ELECTRIC CO.
To:
Shared Package
ML20091F935	List: ML20092C737 ML20092C771 ML20092C780 ML20092C809 ML20092C828 ML20092C845 ML20092D229
References
FOIA-95-188 GENE-771-83-119, GENE-771-83-1194-R01, GENE-771-83-1194-R1, NUDOCS 9509130136
Download: ML20092C780 (15)

Text

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ProprietaryDocument ggyg_77g.g3 9;94 Rev.1 GC Nuclear Enernv DRF B13-01749 -

GE Nuclear Energy COMMONWEALTH EDISON COMPANY DRESDEN NUCLEAR POWER PLANT UNITS 2 AND 3 SHROUD AND SHROUD REPAIR HARDWARE ANALYSIS VOLUME I: SHROUD REPAIR HARDWARE l BACKUP CALCULATIONS Prepared by: d b 'ItM/aJL Date: f//f/75"

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Date:

Y.Wu Verified by: Ww - Date: 5!!y!I M. ul r

@- . /jin MM pal Engineer, Ph.D. Date: J [/z M J

M.wu 1

Approved by: : [ Date: O M/f[

K. Kanm-Panahi, Ph.D., Principal Eng, N Date: 8[I 2-[6 M. Potter, Principal Engineer i

Backup Calculations or Dresden Shroud Repair Hardware Stress Report Page 1 9509130i36 9588'30 IN 88 PDR

PropnetztyDocument GENE-771-831194 R:v.1 GE Nuclear Enerav DRF B13-01749 -

- ABSTRACT 2

Volurnes I and ll of this document provide the results of the stress analysis of the Dresden 2 and 3 and Shroud Repair Hardware, demonstrating that structural integrity is maintained when subjected to the loading and limits specified in Design Specification 25A5688.

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j- ProprietuyDocument GENE-771-63-1194 R:v.1 5* GE Nuclear Enerov DRF B13-01749

EXECUTIVE

SUMMARY

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This report provides the results of the stress analysis of the Dresden Units shroud and

- shroud repair hardware when subjected to all applied loadings including seismic, pressure, deadweight, and thermal effects.

The shroud restraint hardware consists of four identical sets of tie rod and spring assemblies. The four sets are spaced 90" apart, beginning at 20 from vessel zero. ,

, Each set consists of the following major elements:

! 1. An Upper Spring, located in the reactor pressure vessel (RPV)/ shroud annulus at the top guide elevation. This spring provides lateral seismic support to the shroud at the top guide elevation and transmits seismic loads from the nuclear core directly to the RPV.

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2. An Upper Support Assembly, located in the annulus from the top guide elevation to the top of the shroud. This assembly provides a connection for the tie rod to the shroud top.

l 3. A Middle Spring, located in the annulus at the elevation of the jet pump support brackets. This spring provides lateral seismic support to the shroud, j keeps the shroud from coming in contact with the jet pump support brackets during a seismic event, and restrains the tie rod movement for proper tie rod i vibration characteristics.

4. A Lower Spring, located in the annulus at the core plate and shroud support l

< region. This spring provides lateral seismic support to the shroud, transmitting core seismic loads to the RPV. In addition, this spring provides a connection for the tie rod to the shroud support plate. l i i i

1 5. The Tie Rod, which connects to the upper end of the top of the shroud and to the lower end of the lower spring. This component develops a thermal 4

preload due to normal operating temperature, which in tum provides vertical 4 clamping forces to the shroud.

The upper, middle and lower springs are optimized to transfer the lateral operational,

hydrodynamic and seismic loads while meeting the stress limits.

i Back.'o Calculatons for Dresden Shroud Repair Hardware Stress Report Page 3

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Proprietary Document GENE-771-63-1194 R5v.1

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GE Nudear Enerav DRP B13-01749 The stress analysis of the overall core shroud was performed with the ANSYS code

[ Reference 1). A three-dimensional finite element model was constructed which included the shroud from the upper flange at the shroud head joint down to the connections at the RPV. Because of the symmetrical behavior of the shroud under the applied loads, a 180 circumferential segment was modeled.

The stress analysis of the major shroud repair hardware components was performed with the COSMOSM [ Reference 10] and ANSYS codes. For the smaller components, hand calculations were performed.

I The load combinations and structural acceptance criteria are contained in the Design Specification [ Reference 2]. The results of the stress analysis demonstrate that the shroud and shroud repair hardware meet the requirements of that specification.

The Volume I of this report is describing the analysis of the shroud repair hardware.

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Propnet1ry Document GENE-771-83-1194 ,

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GE Nuclear Enerov DRF B13-01749 t

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IMPORTANT NOTICE REGARDING THE CONTENTS OF THIS REPORT The only undertaking of the General Electric Nuclear Energy (GENE) respecting .

Inibrmation in this document are contained in the contract between Commonwealth '

Edison (Comed) and GENE, and nothing contained in this document shall be construed as changing this contract. The use of this information by anyone other than Comed, or for any purpose other than that for which it is intended, is not authorized; and with respect to any unauthorized uss, GENE makes no representation or warranty and 1 assumes no liability as to the completeness, accuracy, or usefulness of the information containedin this document.  ;

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ProprietaryDocurnent GENE 471-83-1194 Rsv.1 '

GE Nuclear Enerav DRF B13-01749 J

Table of Contents l l

Page i l

ABSTRACT......................................................................................... 2 EXE C UTIVE S U MMA RY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . .. . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . 3 4 LI ST OF FIG U RE S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . .. . . . .. . . . . . . . . . . . . . . . . . . . . . . .. . . 7 1.0 I N TR O DU C TI O N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 .....  ;

3 2.0 SHROUD REPAIR HARDWARE DESIGN FEATURES ..................... 9 i 3.0 MATERIAL PROPERTIES .. .... .. ....... . .. . . . . .... . . .. ... ... ...... .. ...... .. .. . .... ....... 12 l 3.1 TieRod..................................................................................... 12 l 3.2 Spring and Upper Assemblies ............................................... 12 4.0 LOADS AND LOAD COMBINATIONS . ...................................... ...... 13  :

5.0 STRUCTURAL ACCEPTANCE CRITERIA ........................................ 15 6.0 SHROUD REPAIR HARDWARE STRESS ANALYSIS ...................... 16 6.1 S hroud Upper Stabilizer ............ . . .............................................. 17 6.1.1 I NTRO D U CTI O N . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . .. 17 l 6.1.2 ANALYSI S M ETH O D .. .. . .. . . . . . . . . .. ........ .... .. ... . . . .. . . . . .. . .. . .... 17 i 6.1.3 MATERIAL PROPERTIES AND APPLIED LOADS ..... .. 17 6.1.4 M O DELI N G DETAI LS .... . . . .. . . ... . ....... . ... ... ... . . . . .. . .. ... . . .... . 18 6.1.5 ANALYSI S R ES U LTS . . ... . . . . . ... . .... ....... ..... .. .. . . .... . . ... . . . .... 20

! 6.1.6 S PRIN G CON STANT .. . . .. . . . . . . . . . . .... ..... . .. . . . .. . . . . . . . . .. . ... . .. .. 20

! 6.1.7 UPPER SPRING STRESS EVALUATION ..................... 26  :

6.1.8 UPPER STABILIZER HORIZONTAL SPRING CONST. . 27 l 6.2 S h ro u d Lowe r Sta bilize r . .. .. .... ... .. . . . . . .. . .. .. . . .... . ... .. . ... . . . .... .. . . . . . .. .. 28 i 6.2.1 1 N TR O D U CTl O N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . .. .. 28  !

6.2.2 ANALYSI S M ETH O D . . . . . . . . . .. .. . ... . . . . . .. . . . .... .. .. .. .. . .. .. . ... . . .. 28

- 6.2.3 MATERIAL PROPERTIES AND APPLIED LOADS ........ 28

6.2.4 MOD ELI N G DETAI LS ..... . .. ...... ................. ............. ...... 29

6.2.5 ANALYSI S R E S U LTS .. .. . . .. .. . . .. .... .... ... ... ... .. . ..... . .. . . ... .. .. 32 6.2.6 S PRIN G C ON STANT . . .. . . ... . . .. . . .. .. . .. .. .... . .. .. . ... .. . ... . . . . . ... . 32 i 38 6.2.7 LOWER SPRING STRESS EVALUATION......................

6.2.8 LOWER STABILIZER HORIZONTAL SPRING CONST.. 40 6.2.9 LOWER STABILIZER VERTICAL SPRING CONST........ 41 6.3 Long U ppe r S u p port . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . .. . . .. . . . . . . . . . . . . . . . . . . . .. . . 42 B ra cket Yoke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 6.4 .

6.5 M id d le Sp rin g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 6.6 TieRod..................................................................................... 54 l 6.7 Lower Support and Toggle Assembly ....................................... 57 REFERENCES.................................................................................. 58 Backup Calculatoons for Dresden Shroud Repair Hardware Stress Report Page 6 i

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l. Proprietary Documerd l GENE-771-83-1194 Rev.1 GE Nudaar Enerav DRP B13-01749 i

Table of Contents (Continued)

Attachment A - Design Drawings ....................................................... 59 Attachment B - Selected FE Analysis Stress Outputs........................ 63 Attachment C - Upper Spring Selected FE Analysis Stress Output... 66 Attachment D - Lower Spring Selected FE Analysis Stress Output... 95 Attachment E - Upper Spring Finite Element Model input ................. 150 Attachment E Upper Spring Finite Element Model input, Normal. 151 Attachment E Upper Spring Finite Element Model input, Emerge 194 ,

Attachment E Upper Spring Finite Element Model input, Fautted 195 l

Attachment F Long Upper Support FE Anslysis Run "BBKT-5"... 196 Attachment F Bracket Yoke FE Anslysis ANSYS Run " YOKE-2". 225 Attachment F Middle Spring FE Anslysis ANSYS Run "MSPR-1" 235 Attachment F Tie Rod FE Anslysis ANSYS Run "TR-3"............... 285 Att. G - Lower Spr. FE Model input 286 Att. G-1 Lower Spr. FE Model input, Normal Condition, Hz Load ....... 287 Att. G-2 Lower Spr. FE Model input, Normal. Condition, Vert. Load... 339 Att. G-3 Lower Spr. FE Model input, Emerg. Condition, Hz Load ....... 340 Att. G-4 Lower Spr. FE Model input, Emerg. Condition, Vert. Load.... 341 Att. G-5 Lower Spr. FE Model Input, Faulted Condition, Hz Load....... 342 Att. G-6 Lower Spr. FE Model input, Faulted Condition, Vert. Load ... 343 Att. G-7 Lower Spr. FE Model input, Horiz. and Vertical Stiffness . .... 344 I

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Backup Calculatons forDresden ShrrE tepair Hart 1 ware Stress Report Page 7

Propriet:ry Docurnent GENE-771-83-1194 Rev.1

. GE Nuclear Enerav DRF B13-01749 List of Figures Figure Page 2.1 Shroud Repair Hardware Layout ...................................................... 10 2.2 Shroud Horizontal Weld Designations .............................................. 11 6.1.1 Upper Spring Finite Element Model .................................................. 19 6.1.2 Upper Spring Normal / Upset Condition, Stress intensity.................... 21 6.1.3 Upper Spring Emergency Condition, Stress intensity........................ 22 6.1.4 Upper Spring Faulted Condition, Stress intensity.............................. 23 6.1.5 Upper Spring Faulted Condition, Displacement ................................ 24 6.1.6 Upper Spring Faulted Condition, Deformation ................................. 25 6.2.1 Lower Spring Finite Element Model .................................................. 28 6.2.2 Lower Spring Normal / Upset Condition, Stress intensity.................... 30 6.2.3 Lower Spring Emergency Condition, Stress Intensity........................ 31 6.2.4 Lower Spring Faulted Condition, Stress Intensity.............................. 32 6.2.5 Lower Spring Faulted Condition, Displacement ................................ 33 6.2.6 Lower Spring Faulted Condition, Deformation ................................. 34 6.3.1 Long Upper Support FE Model and Boundary / Loading Conditions 36 6.3.2 Long Upper Support FE Analysis Stress Plots .................................. 37 6.4.1 Bracket Yoke FE Model and Boundary / Loading Conditions............ 39 6.4.2 Bracket Yoke FE Analysis Stress Plots ............................................. 40 6.5.1 Middle Spring FE Model and Boundary / Loading Conditions.......... 42 6.5.2 Middle Spring FE Analysis Stress Plots............................................. 43 6.6.1 Tie Rod FE Model and Boundary / Loading Conditions .................... 45 D.1 Lower Spring finite element center nodes, upper part ...................... 148 D.1 Lower Spring finite element center nodes, lower part ....................... 149 r

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. Proprietuy Document 1 GENE-771-83-1194 Rzv.1 GE Nuclear Enerav DRP B13-01749 i

COMMONWEALTH EDISON COMPANY l DRESDEN NUCLEAR POWER PLANT UNITS 2 AND 3 i SHROUD AND SHROUD REPAIR HARDWARE ANALYSIS

VOLUME l

SHROUD REPAIR HARDWARE ,

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1.0 INTRODUCTION

l Intergranular stress corrosion cracking (IGSCC) has been found in the core shroud welded joints of several Boiling Water Reactors. Similar cracking may also exist in the weldedjoints of the Dresden Units 2 and 3 Core Shroud. GENE has designed a shroud l l I repair system that reinforces the shroud in the event that any or all of the seven shroud horizontal weld joints are cracked. The stress analysis discussed in this report demonstrates that the shroud and the shroud repair system structural integrity is  !

l rnaintained if any or all of these seven welded joints are cracked completely through their thickness and around their entire 360 circumference. The structural integrity of the shroud and shroud repair system is also demonstrated in the event that the shroud l l

is uncracked and the repair system is installed.

The Volume I of this report is describing the analysis of the shroud repair hardware.

Backup Calculat ons for Dresden Shroud Repair Hardware Stress Report Page 9

Propnetory Docurnent GENE-771-83-9194 Rev.1 GE Nuclear Enerav DRP B13-01749 -

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2.0 SHROUD REPAIR SYSTEM DESIGN FEATURES The shroud repair system consists of four identical sets of tie rod and spring

. assemblies.' The four sets are spaced at 90 intervals beginning at 20* from vessel zero. A layout of one of the tie rod and spring sets is shown in Figure 2.1.

The tie rods are thermally preloaded to provide vertical compressive clamping forces on j the shroud. The magnitude of the tie rod thermal preload is greater than the net uplift i forces on the shroud due to normal operating pressures and postulated Loss of Coolant i Accident (LOCA) recirculation line break pressures, so that no vertical separation of shroud sections would occur in those cases if the welded joints are postulated to be complet61y cracked. This is not the case for postulated LOCA main steam line break i uplift pressures, which are sufficient to overcome the tie rod preload and momentarily I separate shroud sections. ,

i The upper, middle, and lower springs provide a lateral seismic load path from the top guide and core plate to the RPV. The magnitude of the seismic loads in these springs

! is a function of their stiffness. The stiffness has been optimized to minimize the seismic l

loads while still meeting the stress and displacements limits. The U-shaped upper j springs consists of tapered legs that flex towards each other under lateral seismic

loads. The taper in these legs has been optimized to produce constant stress along j their length while providing the required stiffness. For the middle spring, the flexibility of I the taper beam section provides the needed lateral stiffness to keep the middle section

of the shroud from coming in contact with the jet pump support brackets during a seismic event. This keeps the shroud from moving closer than 1/2-inch to the jet pump

! support bracket. The rigid middle section of the middle spring also provides an

intermediate lateral support to the tie rod. The natural vibration frequency of the tie rod l with this intermediate support is then well removed from the flow-induced forcing

!- frequency (flow induced vibration is discussed in detail in Section 6.6). For the lower j spring, the flexibility of the Y-shaped feature at the top provides the lateral stiffness i I

property, whereas the flexibility of the straight middle section provides the axial stiffness property, which in combination with the stiffness of the tie rod and upper axial l

! component determines the tie red thermal preload. ]

The shroud geometry and location and designation of the seven shroud horizontal weld joints are shown in Figure 2.2.  ;

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• Enclosure 10 GENE 771-85-1194, Revision 2 Dresden Units 2 & 3, Shroud Repair Seismic Analysis Backup Calculations General Electric Nuclear Company Proprietary Information 4

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GENE.771-851194 4 , GE PROPRIETARY nrvisen 2

.; - GE NUCLEAR ENERGY DRF B13-01749 Table of Contents Page 1.0 Seismic Methodology 3 2.0 Seismic Model 4 3.0 Seismic Analysis 6 4.0 Additional Information 8 5.0 References 9 Calculations 10 j 1

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Enclosure 9 GENE-771-84-1194, Revision 2 Dresden Units 2 & 3, Shroud Repair Seismic Analysis

General Electric Nuclear Company Proprietary Information 1

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1 k:\nla\dreulen\ shroud \d52495.spf l

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GENE-771-84-1194 o- .. . GE PROPRIETARY Revision 2  ;

GE NUCLEAR ENERGY one g93.o374g p

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Table of Contents 4

Page .

1.0 Introduction 3 2.0 Seismic Model 4 ,

1 3.0 Seismic input 7 l 4.0 Seismic Analysis Results 8 i

5.0 References 9 l

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4 Enclosure 11 GENE Stress Report,25A5691, Revision 2 Pressure Vessel - Dresden Units 2 & 3 L

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. .- 25A5691 'SH. NO.1 GENuclearEnergy REv. 2 1

REVISION STATUS SHEET DOC TITLE PRESSURE VESSEL LEGEND OR DESCRIPTION OF GROUPS D'PE: STRESS REPORT pgy. DRESDEN 2 AND 3 MPL NO: PRODUCT

SUMMARY

SEC. 7 1 THIS ITEM IS OR CONTAINS A SAFET/ REI.ATED TIT.M YES 5 NO EQUIP CLASS P

. REVISION C 0 RM-01879 S-07-95 1 J. L. TROVATO 03/27/95 RJA -

CN 02342 CHK BY: J. L. TROVATO 2 J. L. TROVATO RJA SY 121995 CN 02615 .

CHK BY: J. L. TROVATO p

PRINTS TO MADE BY APPROVALS GENERAL ELECTRIC COMPANY J.L. TROVATO 2/6/95 175 CURTNER AVENUE A.S. HERLEKAR 3/07/95 SANJOSE CALIFORNIA 95123 CHK BY ISSUED BY J.L TROVATO 3/01/95 R.J. AHMANN 3/07/95 CONT ON SHEET 2

- [;-^L,020159- 950524ADOCK 0500 g .

4

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9' ENuclearEnergy 25A5691 ev. 2 SH. NO. 2 l 1.0 SCOPE This document is the ASME Code Section III Paragraph N-142 Stress Report for the Reactor Pressure Vessel. This analysis addresses the new loads applied to the vessel as a result of the installation of the shroud stabilizers which function to replace the horizontal girth welds H1 through H7 and weld H8 in the core shroud.

2.0 APPLICABLE DOCUMENTS 2.1 General Electric Documents. The following documents form a part of this stress report to the extent specified herein.

Subject Document Number

a. Code Design Specification 25A5689 Rev.I

b. Shroud Repair Hardware Design Specification 25A5688 Rev.2

c. GE Drawing-Reactor Vessel SH-4 885D660 Rev.8 Rev.6

d. GE Drawing-Vessel Loading 885D910

e. GE Drawing-Detail, Suppon Lowgr 112D6664 Rev.0 1

. f. GE Drawing-Detail, Contact Lower 112D6667 Rev.O  !

g. GE Drawing-Detail, Contact Middle 112D6681 Rev.1 l

h. GE Drawing-Detail, Contact Upper 112D6666 Rev.0

i. GE Drawing-Reactor Thennal Cycles 921D265 Rev.1

j. GE File-Shroud Suppon Dresden 2 VPF # 1248-114-4

k. GE File-RPV Stress Report for Dresden 2 VPF # 1248-436-1  ;

1) Report # 8 Rev. 5-Suppon Skin Analysts

2) Report # 10 Rev. 6-Brackets i

3) Report # 11 Rev. 4-Shroud Support System Analysis l

4) Repon # 20-Rev. 3-Shell Analysis

.l. GE Shroud Mechanical Repairs Program GENE-771-84-1194 Dresden 2 & 3- Seismic Analysis Rev 2  :

.m. GE File-Shroud Suppon Dresden 3 VPF # 2252-131-3 l

n. GE File-RPV Stress Repon for Dresden 3 VPF # 2252-181-1 ,

1) Repon # 8 Rev. 5-Suppon Skin Analysis

2) Repon # 10 Rev. 6-Brackets j

3) Report # 11 Rev. 4-Shroud Support System Analysis l

4) Repon # 20-Rev. 3-Shell Analysis 2.2 Codes and Standards. The following documents of the specified issue form a pan of l this specification to the extent specified herein. l 2.2.1 American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code

a.Section III,1963 Edition and Addenda through Summer 1964 ( Dresden 2 )

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25A5691 SH. NO. 3 9'

GENuclearEnergy anv. 2

b.Section III,1965 Edition and Addenda through Summer 1965 ( Dresden 3 ) l l

2.2.2 Other Documents

a. "Roark's Formulas For Stress & Strain", by W. C. Young,6* Edition

b. " Theory of Plates and Shells", by S. Timoshenko,2"d Edition i

3.0 GENERAL DESCRIPTION i

3.1 Purnose l ne purpose of the shroud stabilizers is to structurally replace all of the horizontal ;

ginh welds in the core shroud and and weld betweeen the shroud cylinder and the i

shroud suppon plate. These welds provide suppen for the cylindrical plate sections, '

and the shroud head, and prevent core bypass flow from exiting to the downcomer region. The core top guide and core suppon plate horizontally suppon the fuel assemblies and maintain the correct fuel channel spacing permitting control rod insertion. .

l 3.2 Desin Recuirements  ;

The design requirements for the shroud stabilizers were separated into two documents. The first document addressed those requirements that were not under the jurisdiction of the ASME Code (Paragraph 2.1.b). The second document addressed those requirements that were under the jurisdiction of the ASME Code (Paragraph 2.1.a).

3.3 Accentability i This Stress Repon documents the acceptability of the structural integrity requirements of the Code Design Specification defined in Paragraph 2.1.a. He original B & W stress repon for Dresden 2 ( 2.1.k ) and for Dresden 3 ( 2.1.n ) are indentical except their VPF numbers. Therefore, any reference to 2.1.k implies reference to 2.1.n also. Where data for Dresden 2 ( 2.1.j ) differs from Dresden 3 data ( 2.1.m ), the most conservative of the two values are used in the calculations and are specifically indicated.

4.0 ANALYSIS  !

4.1 General l

The Design Specification (2.1.a) defines four new design mechanical loads on the  !

reactor pressure vessel. These loads and their point of application are shown in l j

Figure 1 and Table 1. These loads are separated by a distance of approximately l l

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t SH. NO. 4 9 GENaciearEnergy 25A5691 nev. 2 equal to 70" ( See Figure 1 ) and therefore, can be treated as separate forces. Each of F1, F2, F3 and F4 are addressed in sections 4.2 through 4.6.

42 Evaltiation for load F1

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The force F1 is applied to the reactor pressure vessel (RPV) shell 72 inches above

, the shroud support plate. It is a local force applied in the radial direction by the j shroud repair during a Design Basis earthquake (DBE). At this elevation the RPV shell is 6.125 inches thick minimum ( page B-2-2 of 2.1.k.4).

4 4.2.1 Compute stresses induced in RPV due to F1 applied radially to RPV shell at approximately 72 inches above the support plate durmg DBE:

Use theory of plate and shells by S. Timoshenko (2.2.2.b, pg. 471)

! R;=125.5" Inside radius of RPV

. o h = 6.125" Thickness of RPV shell exclusive of cladding

a =125.5 + 6.125/2 = 128.563" mean radius

! r 31/4 2

3(1 - v )

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y u 0.30 Poisson's ratio (2.1.k.4) )

= 0.046 4 Mu, = P/4p and P = Fl/21 where 1 is contact width of upper contact plate, 5" for F1 & 2" for F2 & 4" for F3 l (2.1.f through 2.1.h).

Mm =0.543F1 or 1.358F2 & 0.679F3 k-in/in.

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1 From paragraph 2.2.2.b page 474 deflection under load is Pa py(2Eh)= 0.00021F1 or 0.00052F2 or 0.00026F3 in. since E = 29.4 x Wp((2.1.k.4) 10' ksi.

I And 1/2 = (3xrI) / (4xp) is the length over which deflection due to radial load  ;

become zero on either side of the point of the application of the load.  !

1/2 = (3xII)/ (4x0.046) = 51.22 in.

oi = c = Longitudinal Stress

' c = c = Tangential Stress i

Pm = Prunary membrane stress intensity Pl = Primary local membrane stress intensity

25A5691 SH. NO. 5 S' GENucleiar Erwrig)r Pb = Pnmary bending stress intensity asv. 2 2

c2 = ci = 6Mm/h = 0.087 F1 or 0.218 F2 or 0.109 F3 ksi 2

i a; = c = 6 v Mm/h + E Wmax / ot = 0.074 F1 or 0.186 F2 or 0.093 F3 ksi 4.22 For Faulted condition F1 = 190 kips. the maximum value of P1 stress intensity due to this load is negligible and the maximum value of Pb stress intensity due to this load is = 0.087 x 190 =16.53 ksi. These stress intensities occur directly under the point ofload application.

. 4.2.3 The existmg pnmary local membrane stress intensities in the shell per the original Stress Report (Paragraph 2.1.k.4, Page B-19-2) are 12.8 ksi (PI) and also (P1 + Pb).

4 4.2.4 The new value of P1 issame as original value of 12.8 ksi. The new value of(P1 +

Pb) can be conservatively calculated as 12.8 + 16.53 = 29.33 ksi.

4.2.5 The allowable value of primary membrane Pm stress i . tensity is Sm, which equals 26.7 ksi, and the allowable value of primary local (PI) plus pnmary bending (Pl +

Pb) stress intensity is 1.5Sm, which equals 40 ksi. (paragraph 2.1.k.4).

4.2.6 The Emergency load F1 is almost same as ( only 4 kips. less ) Faulted load F1 and thus the new value of(Pl + Pb) is 28.98 ksi. which is below the allowable of 1.5Sm

= 40 ksi. per 2.1.k.4.

4.2.7 Primary stress intensity (Pb) for normal / upset condition F1 = 93 kips = 0.087 x 93 l

= 8.09 ksi. and the primary local stress intensity (PI) is negligible. The existing P1 i and (P1 + Pb) are 12.8 ksi. The new P1 = 12.8 ksi while new (Pl + Pb) = 12.8 +

8.09 = 20.89 ksi. < 40 ksi (1.5Sm).

4.3. Evaluation for load F2 Stresses in RPV due to Faulted condition F2 = 24 kips applied at appronmately 188 inches above the shroud support plate can be obtained by scaling from values obtained for F1 = 190 kips. and using the lower contact plate width of 2 inches as value of"!".

ci = 5.23 ksi. And c2. = 4.46 ksi.

4.3.1 The maxunum value of Pl stress intensity due to this load is negligible and the maximum value of Pb is 5.23 ksi. These stress intensities occur directly under the point ofload application.

4.3.2 The existing primary local membrane stress intensities in the shell per the original Stress Report (Page B-19-2 of 2.1.k.4 ) is 12.8 ksi, for (PI) and (Pl +Pb).

4.3.3 The new value of P1 is conservatively same as existing value of 12.8 ksi. 'Ibe new value of P1 + Pb can be conservatively calculated as 12.8 + 5.23 = 18.03 ksi.

25A5691 SH. NO. 6 S @h

^

REV.2 4.3.4 The faulted allowable value of primary membrane stress intensity is Sm, which equals 26.7 ksi. and the allowable valve of pnmary local (PI) and the primary plus bending (Pl + Pb) stress intensity is 1.5Sm, which equals 40 ksi. per 2.1.k.4.

4.3.5 The Emergency load F2 is same as Faulted load F2 and thus the new value of( P1 +

Pb ) is 18.03 ksi. which is below the allowable of 1.5Sm = 40 ksi. per 2.1.k.4.

4.3.6 Since the faulted stress intensities (PI) and (Pl + Pb) are below the upset conditions allowable of 40 ksi., the primary suess intensity for normal / upset condition F2 =

12 kips. is satisfied by inspection as the F2 in upset condidons is lower than F2 of the DBE condition.

l 4.4 Evaluation for load F3 Stresses in RPV due to Faulted condition F3 = 140 kips applied at approximately 244 inches above the shroud support plate, can be obtained by scaling from values obtained for F1 = 190 kips. and using the lower contact plate width of 4 inches as value of"1".

oi = 15.26 ksi. and o2 = 12.97 ksi.

4.4.1 The maximum value of P1 Stress intensity due to this load is negligible and the maximum value of Pb is 15.26 ksi. These stress intensities occur directly under the  !

point ofload applicadon.

4.4.2 The existing pnmary membrane stress intensides in the shell per the original Stress Report (Page B-19-2 of 2.1.k.4) is 12.8 ksi., for ( P1 ) and ( Pl + Pb ).

l 4.4.3 The new value of P1 is conservatively same as existing value of 12.8 ksi. The new i value of( Pl + Pb ) can be conservatively calculated as 12.8 +15.26 = 28.06 ksi. l l

4.4.4 The faulted allowable value of primary membrane stress intensity is Sm, which equals 26.7 ksi. and the allowable value of prunary local ( Pl ) and the primary plus ,

bending ( Pl + Pb ) stress intensity is 1.5Sm, which equals 40 ksi. per 2.1.k.4. l 4.4.5 The Emergency load F3 is almost same as Faulted load F3 ( only 6 kips less ) and thus the new value of ( Pl + Pb ) is 26.79 ksi. which is below the allowable of 1.5Sm = 40 ksi. per 2.1.k.4.  :

4.4.6 Since the faulted stress intensides ( P1) and ( Pl + Pb ) are below the upset conditions allowable of 40 ksi., the ' primary stress intensity for normal / upset condition F3 = 67 kips. is satisfied by mspection as the F3 in upset conditions is lower than F3 of the faulted condition.

. & 25A5691 SH. NO. 7

%W) GENuclearEwgy w2 4.5 Evalnation ofload F4 For RPV Shell The force F4 is applied to vertical plate at 4.25 inches (2.1.e) from the inside surface of the RPV shell (this results in moment ann of 4.25 + 6.125 / 2 = 7.31" at RPV shell center line). He value of F4 is 339 kips. for Faulted and Emergency, and 123 kips.

for Normal / Upset conditions, all without thermal preload, for primary stress

< evaluation. Additionally Normal / Upset condition is also evaluated for primary plus secondary stress intensities ranges along with fatigue using F4 of 194 kips per 2.1.a.

4.5.1 Formulas for Stress Intensity for F4 @ Shell T

Apply F4 as vertical load and it will transfer as axial load V = F4 kips and moment of 7.31 F4 k-in. This load V = F4 kips. and moment 7.31F4 k-in. will be assumed to be resisted by the width of RPV shell equal to the width (b = 13.5"), of the lower support plate (paragraph 2.1.e).

Using analysis methods for edge loads for m (para.1-233 of 2.2.1.a) and direct membrane stress as P/t, the stresses in shell are as follows:

c, = 6 mo /t2 p f f; mo o, = EWo + 6v Rm 1 1

where m, = End moment = 7.31 F4/13.5 k-in/in; t = Thickness of shell = 6.125";

P = F4/13.5 kips /in; E = Young's Modulus = 29.4 x 10' ksi.;

R, - Vessel Mean Radius = 128.563 in.;

v = Poisson's ratio = 0.30; W = Deflection at edge (calculated below).

2 Using para.1-232(2) of 2.2.1.a, the lirriiting value of W o = mo / 2p D, where D = Et3 /12(1-v2 ), p , 4 3(1 - v 2) and substituting values of D, p in tenns of E, t, 1

) Rkt e

2, 1-v R. , the expression for e, can be simplified as o, = 6m8 v+ . And with v = 0.30 o, = 6m, (0.8 5).

I Further, since t = 6.125", the final c, = 0.099F4 ksi., e, = 0.074F4 ksi.

These or,cistresses will be used to calculate the stress intensity by principal stress

. difference formulas. Since shear stress is zero, the principal stresses are ci = o, ;

c2 = c,. Primary stress intensity is maximum of ci, c2 or ei - c2.

25A5691 SH. NO. 8 l

@f@dggy'Cgg REV.2 ]

4.5.2 Evaluation For Faulted Condition Primary local membrane plus bending (P1 + Pb) stress intensity for faulted condition F4 = 339 kips. are as follows:

a, = ci = 0.099 x 339 = 33.56 ksi. And o, = c2 = 0.074 x ',39 = 25.09 ksi.

Thus the maximum primary stress intensity (P1 + Pb) = 33.56 ksi From page B-19-3 of original stress report (2.1.k.4) the existing maximum primary local membrane (PI) & also (Pl + Pb) stress in tangential direction is 12.8 ksi. and 6.4 ksi. in longitudmal direction. And as the major stresses due to F4 are Pb, i.e.;

while F1 = 0.012F4 = 4.07 ksi., Pb is 0.087F4 = 29.49 ksi. out of a total (P1 + Pb) of 33.56 ksi. And the new values will be as follows:

P1 = 6.4 + 4.07 = 10.47 ksi. OR 12.8 ksi.

Pl + Pb = 6.4 + 33.56 = 39.96 ksi. OR 12.8 + 25.09 = 37.89 ksi.

The allowable P1 and Pl + Pb stress intensity is 1.5Sm = 40 ksi. in the original stress report (2.1.k.4).

4.5.3 Evaluation For Emergency Condition Pnmary local membrane plus bending stress intensity (P1 + Pb) and primary local membrane stress intensity (PI) for emergency conditions and the allowable of the original stress report is same in both conditions.

4.5.4 Evaluation For Normal / Upset Conditions Normal / upset conditions evaluations required for primary, primary plus secondary, and peak stress intensities per 2.2.1.a are shown in this section.

4.5.4.1 Pnmary stress intensity evaluation is required for F4 = 123 kips. which will give P1 + Pb = 0.099 x 123 = 12.18 ksi. and P1 = 0.012 x 123 = 1.47 ksi.

The existing primary stress intensity at this location for operating condition is Pl

= 12.8 ksi. and Pl + Pb = 12.8 ksi. (page B-19-3 of 2.1.k.4). Thus the new value of Pl + Pb at this location is Pl + Pb = 12.8 + 12.18 and P1 = 12.8 + 1.47

= 24.98 ksi < l.5S, = 40 ksi. = 14.27 ksi. < Sm = 26.7 ksi.

4.5.4.2 The pnmary plus secondary stress intensity for upset condition load F4 = 194 kips is performed for all 120 cycles including the blow down transient as follows (at R.PV shell):

Conservatively the primary plus secondary intensity stress range for 120 cycles is Sn = 0.099 x 194 = 19.21 ksi. He existing value of same primary plus secondary stress intensity range is 20.4 ksi. (page B-16-1 of 2.1.k.4). Bus the new value of S, = 20.4 + 19.21 = 39.61 ksi. < 35, = 80 ksi.

4.55.3 Fatigue, i.e., peak stress intensity range, evaluation for 120 cycles F4 is as follows:

25A5691 SH. NO. 9 GENuclearEnengy REV.2 S,=K,xb Since S, < 3 S,,, K, = 1.0 2

And there is no stress concentration factor per page B-14-1 of 2.1.k.4 S, = 22.55 (existmg S,, page B-18-2 of 2.1.k.4) + 19.21/ 2 = 32.15 ksi.

N.n = 20000 (Figure N-415(A) of 2.2.1.a)

Usage Factor = UF = 120 / 20000 = 0.006 < l.0 4.6 Evaluation of RPV Shell and Baffle Plate Junction for F4 Load 4.6.1 Evaluation for Weld H8 Uncracked condition Due to the support afforded by jet pump nozzles to the bafDe plate, the load F4 will be essentially distributed over a rectangular plate between RPV shell and jet pump nozzle hole circle with the width equal to the width of the lower support plate as shown below:

4 a >

,,,,,,,,,,,,,,,,,,,,,,,y RPV SheiI h

load uq, p b Simply Supported Simply Supported q y M

Simply Supported j fJet Pump Nozzle}

(Hole Circle j where a = Width of horizontal lower support plate (2.1.e) = 13.5";

b = Distance (radial) between shell inside radius (=125.5") and jet pump nozzle hole circle radius = 226 / 2 = 113"(per 2.1.j and 2.1.m) = 12.5";

q = Distributed load = F4 /13.5 x 12.5 = 0.006F4 ksi.

Using formulas for middle of fixed edge moments (for uniformly loaded plate with one edge fixed, other three edges simple supported) from Timoshenko (2.2.2.b, page 241), the moment My = d 2ql'(symbols per 2.2.2.b). Further, since b / a =

0.907 d2 = 0.0916 from Table 52 of 2.2.2.b. And since 1 = 12.5" (smaller of a =

13.5" or b = 12.5"),

My = 0.0916 x 0.006F4 x (12.5)2 = 0.0859F4 in-kips /in.

2 Further the bending stress o = 6 by /1 and with t = 2.063" (thickness of bafDe plate per 2.1.j ), the bending = stress value is e,= 0.0859F4x 6 / (2.063) 0.1211F4 ksi And shear stress t = F4 / Area = (F4 / (Perimeter x 't') )

= {F4 / [(2) x (12.5 + 13.5) x (2.063)]} = 0.0093F4 ksi.

(,)2 ) v2= 0.121SF4 ksi.

Principal stress oi = 0.1211F4 / 2 + {(0.1211F4 / 2 )2 c2 = 0.1211F4 / 2 - { (0.1211F4 / 2 ) + (T )2 ) v2= -0.0007F4 ksi.

~

SH. NO.10

. 8 25A5691 VG) GENuclearEnergy m2 The maxunum stress intensity = (oi - oy = 0.1225F4 ksi.

4.6.1.1 Evaluation for Faulted Condition l Primary local membrane plus bencling (P1 + Pb) stress intensity for faulted conditions F4 = 339 kips. are as follows:

Thus the maximum primary stress intensity (P1 + Pb) = 0.1225 x 339 = 41.5 ksi The maximum primary membrane plus bending stress intensity at this location from the existing stress analysis (2.1.k.3 page B-16-7) is 0.5 ksi. Therefore, the new maximum primary membrane plus bending (Pl + Pb) stress intensity is = 0.5

+ 41.5 = 42 ksi. which is less than faulted allowable of 3Sm = 80 ksi for carbon steel (vessel material) and also less than the 3Sm = 70 ksi for Inconel (baffle plate material).

i 4.6.1.2 Evaluation for Emergency Condition Prunary local membrane plus bending stress intensity (Pl + Pb) for the Emergency condition F4 = 339 kips. is equal to 0.1225 x 339 = 41.5 ksi. Thus new P1 + Pb = 0.5 + 41.5 = 42 ksi. which is less than emergency condition j allowable of 2.25Sm = 60 ksi for carbon steel (vessel material) and also less than the 2.25Sm = 52.5 ksi for Inconel (baffle plate material).

l t

4.6.1.3 Evaluation for Normal / Upset Conditions 4.6.1.3.1 Evaluation for Pnmary Stress Intensity Primary stress intensity evaluation for upset conditions is required for F4 = 123 l kips. which will give P1 + Pb value of 0.1225 x 123 = 15.06 ksi. (

Re existing pnmary stress intensity for operatmg conditions is 9.6 ksi (page j B-16-7 of 2.1.k.3). Thus the new value of Pl + Pb at this location is l Pl + Pb = 9.6 + 15.06 i

= 24.66 ksi. < l.SSm = 40 ksi for cabon steel, the vessel material

< l.5Sm = 35 ksi for Inconel, the baffle plate material 4.6.1.3.2 Evaluation for Pnmary plus Secondary Stre.ss Intensity The primary plus secondary stress intensity range for upset condition F4 = 194 kips is performed for all 281 loading cycles including the blow-down transient as follows (atjunction of baffle plate and RPV shell):

Conservatively the highest primary plus secondary stress intensity range is for 10 cycles of loss of feed water pump transient and is equal to Sn = 0.1225 x 194 = 23.77 ksi The existing value of the same primary plus secondary stress intensity range is 67.2 ksi. (page C-16-7 of 2.1.k.3). Thus the new value of Sn i l

25A5691 SH. NO. I1

@hlgglfggy REV.2

= 67.2 + 23.77 = 90.97 ksi. > 35m = 70 ksi. ( conservatively, for Inconel, the baffle plate materia!)

4.6.1.3.3 Evaluation for Fatigue Fatigue, i.e., peak stress intensity range, for these 10 cycles is Sp = 88.8 (Existing) + 1.64 x 23.77 = 127.78 ksi. where 1.64 is the bending stress concentration factor as used in the original stress report, pg. B-17-2.

Sa = Ke x Sp / 2. and since Sn > 3 Sm.

Ke = 1.0 + [( 1/n - 1 ) / ( m - 1 )) { (Sn / 3Sm)- l } = 1.6 Sa = 102.22 ksi.

Na = 550 (Figure N 415(A) of 2.2.1.a)

Usage Factor = UF = 10 / 550 = 0.018 4

Similarly calculating the usage factor for remaining 271 cycles, the cumulative usage factor is 0.141 < < l.0, and thus is well below the code limit.

4.6.2 Evaluation for Weld H8 Cracked condition A finite element model using computer program ANSYS was analyzed for this condition. ' Die results are summanzed in this subsection.

4.6.2.1 Evaluation for Faulted Condition i

l Pdmary local membrane plus bending (Pl + Pb) stress intensity for faulted conditions F4 = 339 kips is 59.17 ksi. which is less than faulted allowable of 3Sm = 70 ksi. for Inconel ( baffle plate material ) as well as 3Sm = 80 ksi. for carbon steel ( RPV shell material).

i 4.6.2.2 Evaluation for Emergency Condition Pnmary local membrane plus bending stress intensity (P1 + Pb) for the Emergency condition F4 = 339 kips is 38.27 ksi which is less than 2.25Sm =

52.5 ksi. for Inconel ( baffle plate material ).as well as 2.25Sm = 60 ksi. for i carbon steel ( RPV shell material).

4.6.2.3 Evaluation for NonnalIUpset Conditions 4.6.2.3.1 Evaluation for Primary Stress Intensity Pnmary local membrane plus bending stress intensity (P1 + Pb) for the Emergency condition F4 = 123 kips is 22.43 ksi which is less than 1.5Sm = 35 ksi. for Inconel ( baffle plate material ).as well as 1.5Sm = 40 ksi. for carbon steel ( RPV shell material ).

I  !

k l

- 25A5691 SH. NO.12

@h REV.2 4.6.2.3.2 Evaluation for Pnmary plus Secondary Stress Intensity i

The primary plus secondary stress intensity range for upset condition F4 = 194 kips is performed for all 281 loading cycles including the blow-down transient atjunction of baffle plate and RPV shell.

Conservatively the highest primary plus secondary stress intensity range is for  ;

all 281 cycles is Sn = 44.36 ksi < 3Sm = 70 ksi ( conservatively, for baffle plate material).

4.6.2.3.3 Evaluation for Fatigue l

Fatigue, i.e., peak stress intensity range, for all 281 cycles is Sp = 1.64 x 44.36

= 72.76 ksi where 1.64 is the bending stress concentration factor as used in the l

' original stress report, pg. B-17-2.

Sa = Ke x Sp / 2. and since Sn < 3 Sm, Ke = 1.0 Sa = 36.38 ksi Na = 11000 (Figure N-415(A) of 2.2.1.a)

Usage Factor = UF = 281/11000 = 0.026 < 1.0 4.7 Summarv Evaluation for Dresden Unit 2 & 3 for F1, F2, F3, F4 and their effects on all Code requirements are satisfied as documentect in sections 4.1 through 4.6. All of the stress intensities due to the new design mechanical loads F1, F2, F3, and F4 satisfy the allowable stress intensities of the original Code of Construction (Paragraph 2.2.1.a for Dresden 2 and Paragraph 2.2.1.b for Dresden 3).

4.8 Evaluation of RPV Stabilizer Brackets j The new seismic load on the RPV stabilizer bracket location (F7) is 1120 kips. in DBE and 550 kips. in OBE. Rese when conservatively converted into individual bracket loads result in individual bracket loads of 275 kips. in OBE and 560 kips. in DBE. These loads are greater than the RPV stabilizer bracket seismic loading of 246 kips per document 2.1.d. Thus the effect of F7 (as a result of shroud stabilizer modification) on RPV is reevaluated using the existing analysis ( 2.1.k.2 ). The results of these re-evaluations ( GENE-771-77-1194 ) show that the stress intensities at shell junction as well as the maximum stresses in the bracket legs are below their respective allowable. The highest stress intensity ( including local stresses ) in the shell junction is 42.83 ksi. which is below the allowable of 80 ksi. ,

\

M 25A5691 SH. NO.13 W

GENudearErmegy asv. 2 4.9 Evaluation ofRPV Skirt The new seismic shear and ovenuming moment on the base of RPV skirt are F5 and M5. The maximum of these values are F5 = 1100 kips and M5 = 25220 kip-ft in Upset conditions while in Faulted conditions they am F5 = 2220 kips. & M5 = 50870 kip ft (Emergency condition values are slightly lower than Faulted condition values).

These values are not the same as the seismic values of H = 870.72 kips and M =

i 25,200 kip-ft used in the original skirt stress analysis repon (page r$-19-3 of 2.1.k.1).

The bending moments in the original analysis & the present analysis are of the same nature, but have different numerical values. The original bending moments were calculated based on the seismic horizontal design acceleration coefficient of 0.4g and taking the summation of the moments of the horizontal seismic loads located at the center of gravity ( C. G.'s ) of each load, causing the overturning moments. This was given in Table G of GE drawing 885D910 ( 2.1.d ) for the original analysis. In the present analysis the bending moments are taken directly from the dynamic analysis '

of the seismic model. The details are available in GENE-771-84-1194 ( 2.11). This  ;

analysis was performed using time-history methodology.

He original seismic axial load was based 'on a venical acceleration coefficient ( =

0.08g OBE ) multiplied by the total downward load. This axial load has not been changed in the present analysis even though the venical acceleration coefficient is 0.067g in OBE per Dresden UFSAR The present analysis ( GENE-771-77-1194 )

also documents the qualification of RPV skin for DBE seismic while original analysis was performed for only OBE canhquake.

Therefore, the RPV skirt stresses are re-evaluated using the analysis of the existing stress repon # 8. The results of these re-evaluations ( GENE-771-77-1194 ) show that the maximum stresses in the skin are below their respective allowable. The highest direct and shear stress in the skin are 26.87 ksi. & 13.53 ksi. which are below the allowable of 40 ksi. and 16 ksi. respectively.

i 4.10 Evaluntion of Shroud Suonort System The new seismic shears and overturning moments on the base of shroud suppon are F6 and M6. He maximum ( envelope of cracked and uncracked shroud ) of these values are F6 = 520 kips and M6 = 10820 kip-ft in Upset conditions while in l Emergency and Faulted conditions they are F6 = 1090 kips and M6 = 23080 kip-ft.

Rese values are not the same as the seismic values of H = 945 kips and M = 6000 kip-ft used in the original stress analysis repon (page B-11-1 of 2.1.k.3), l Additionally there is an axial load on the suppon legs due to tie-rod attachment at l the top of the shroud. Herefore, the stresses in shroud support system are re- )

evaluated using the analysis of the existing stress repon # 11. The results of these j re evaluations ( GENE-771-77-1194 ) show that the maximum stresses in the l l

SH. NO.14 6 25A5691 W

GENuclearEnengy uv 2 shroud suppon system are below their respective allowable. The highest prunary stress intensity is 32.53 ksi which is below the allowable of 32.5 ksi. The highest usage factor is (at the junction of suppon leg and RPV shell) 0.07 < l.0. Bus the shroud suppon system meets all code allowable.

The shroud support legs were checked for buckling in the original stress report for dead weight plus OBE loads ( 2.1.k.3 ) with factor of safety of 1.97 against yield stress. In the present analysis, the load on support legs is same in both weld H8 uncracked and cracked. Therefore, only one check for buckling is performed in the present analysis. This check for buckling is performed ( GENE-771-77-1194 )

under vertical & horizontal seismic loadings. The factors of safety for buckling under various conditions ranges from a low value of 1.2 based on short column theory & 4.2 based on long column theory ( Faulted and Emergency condition ) to a high value of 13.8 based on shon column theory & 82.3 based on long column theory ( Normal condition ). Thus the support legs are adequetely supported against buckling failure.

5.0 Certification Based on the best of my knowledge and belief, it is hereby cenified that the analysis documented in this Stress Repon satisfies the requirements of ASME Boiler and Pressure Vessel Code Section III,1963 Edition with Addenda through Summer 1964

( Dresden 2 ) & 1965 Edition with Addenda through Summer 1965 ( Dresden 3 ) and Design Specification listed in Paragraph 2.1.a. This certification is provided as required by Paragraph N-142 of said Section III.

Signature: ar b Date: 7 /* f3

/ /.

License Number- C23562 State: California gBOFESSlog

$ # ep N %,

+ ,e

$ $p c 2sssa

$ CML t 9E OFCh&Op l

~

25A5691 SH. NO.15 REV.2 GE' h E w w Iaide) ADDmONALDESIGN AE.CHANICALLOADS Normal / Upset Emergency Faulted Remarks Force F1 Primary Stress Only 93 kips 186 kips 190 kips F2 Primary Stress Only 12 kips 23 kips 24 kips F3 Pnmary Stress Only 67 kips 134 kips 140 kips F4 Primary Stress Only(Note 3) 123 kips 339 kips $39 kips

- Pl+Pb+Q+F Stresses Only 194 Kips -

F7 550 kips 1100 kips 1120 kips RPV Stabilizer Bracket Seismic load F5 1100 kips 2210 kips 2220 kips Seismic Shear @ RPV skirt MS 50870 K-ft Seismic Moment @ RPV 25220 K-ft 50440 K-ft l skirt M6 23080 K-ft Seismic Moment c Shroud 10820 K-ft 23080 K-ft Support F6 520 kips 1090 kips 1090 kips Seismic Shear e Shroud ]

Support l l

NOTES 1)F1, F2, F3 are discrete loads applied over a small area. At any one point in time, F1, F2, F3 are each applied to one location. At any one point in time, F4 is applied to 4 tie rod locations locations 90* apart for the installation of l

)

four shroud stabilizer assemblies. The load F4 shown is maximum and applies to one of any two tie rods 180 l

degrees apart, while the remaining three tie rods have loads lower than F4 values shown above.

I 2)Re stress intensities shall meet the stress allowable of the ASME Code, Section 111, for the load combinations dermed by the Dresden UFSAR. Faulted and Emergency load mcomb' ations shall meet the stress allowable as defined by the Dresden UFSAR for the reactor pressure vessel. 1

3) Loads Fl. F2, F3, F4 to be used in the primary stress evaluation are from document 2.1.a. Loads FS, F6, F7, M5

& M6 are taken from 2.11 l l

!i l

i

25A5691 SH. NO.16

@M REV.2 1

4

{

R = 128.563" St.h411rer Brecket t = 6.125" n [ D 2.5 E = 70.2" RPV Shell n *D a - F2 Shroud 244 in.

188 in. f 72 A F4

- + FE

' ir 2r 3, ,

M6 4.25 A d Figm 2 ,

[ N- s / Yessel Skirt as Fs :

1. M ##/

FIGURE 1. APPLICATION OF DESIGN MECHANICAL LOADS i

i

i i

SH. NO.17 b' 25A5691 W

GENuclearEnengy anv. 2 RHAL.

1 I

m SECTION lli NON-CODEINTERNALLY - CLASS A SUPPORTED STRUCTURE' py NALYZED IN

SEC. 4.3 ANALYZED IN SHROUD SUPPORT A SEC. 4.4 q

CYLINDER 2 A ANALYZED IN s SEC. 4.2 2 #

% s ANALYZED IN 1

s s SEC. 4.5 s

\ ' a l

/ j STRUCTURAL WELD DEPOSIT i j/ 7 SHROUD SUPPORT Analyzed in q' l' PLATE SEC. 4.6 >

I FIGURE 2. BOUNDARY OF ASME CODEJURISDICTION i

l Enclosure 12 4 GENE 771-77-1194, Revision 2 Shroud Repairs Program for Dresden Units 2 & 3 Back-up Calculations for RPV Stress Report No: 25A5691 3

General Electric Nuclear Company Proprietary Information I

i i

1 i

k:\nla\dresden\ shroud \d52495.spf

.