ML20134A782

Rev 3 to Series 44 & 51 Design SG Tube Repair Using Tube Re-Rolling Technique, Final Rept

ML20134A782
Person / Time
Site:	Prairie Island
Issue date:	01/31/1997
From:	ABB COMBUSTION ENGINEERING NUCLEAR FUEL (FORMERLY
To:
Shared Package
ML20134A768	List: ML20134A766 ML20134A774 ML20134A782
References
CEN-620-NP, CEN-620-NP-R03, CEN-620-NP-R3, NUDOCS 9701290089
Download: ML20134A782 (74)

Text

-. . . _ . - - - .. .. . _ . - . - . . -_. . ___- _,_. - -_ - . . . . .. . .._.=... _. - .. _.

4 ATTACHMENT 2 l Combustion Engineering, Inc.

Report CEN-620-P Revision 03-NP Series 44 & 51 Design Steam Generator Tube Repair Using a Tube Re-Rolling Technique January 1997

(65 Pages)

Non-Proprietary l

l l

l i

s 9701290009 970120 PDR ADOCK 05000282 p PDR

i Non-Proprietary Copy No. N' CEN-620-NP

Revision 03-NP

! ABB COMBUSTION ENGINEERING January,1997 l

i i

i i

l Series 44 & 51 Desistn l 3

Steam Generator Tube Repair l

Usine A Tube Rerolling Technique

. FINAL REPORT

' i

! l i

ABB Combustion Engineering Nuclear Operations Windsor, Connecticut ABD MND ASEA BROWN BOVERI

i 4

LEGAL NOTICE THIS REPORT WAS PREPARED AS AN ACCOUNT OF WORK SPONSORED BY ABB COMBUSTION ENGINEERING. NEITHER ABB COMBUSTION l ENGINEERING NOR ANY PERSON ACTING ON ITS BEHALF: l l

A. MAKES ANY WARRANTY OR REPRESENTATION, EXPRESS OR IMPLIED ,

INCLUDING THE WARRANTIES OF FITNESS FOR A PARTICULAR I PURPOSE OR MERCHANTABILITY, WITH RESPECT TO THE ACCURACY, l COMPLETENESS, OR USEFULNESS OF THE INFORMATION CONTAINED  !

IN THIS REPORT, OR THAT THE USE OF ANY INFORMATION, I I

APPARATUS, METHOD, OR PROCESS DISCLOSED IN THIS REPORT MAY NOT INFRINGE PRIVATELY OWNED RIGHTS; OR B. ASSUMES ANY LIABILITIES WITH RESPECT TO THE USE OR FOR DAMAGES RESULTING FROM THE USE OF, ANY INFORMATION, APPARATUS, METHOD OR PROCESS DISCLOSED IN THIS REPORT.

l ii

i t

ABSTRACT i

I A technique is presented for repairing degraded steam generator tubes in Westinghouse i pressudzed water reactors with Series 44 and 51 design steam generators. 'Ibe technique l alleviates the need for plugging or sleeving those steam generator tubes with defects in the j tubesheet region.

i Instead of traditional repair techniques (plugging and sleeving), the degraded tubes will be rerolled above the original tubesheet hard roll to form a new leaktight joint above the initial i

tubesheet roll transition zone. ' Ibis technique will re-establish the pressure boundary between the i primary and secondary side systems and provide the necessary structural capability for operational

, and upset conditions.

This report details analyses and testing performed to verify the adequacy of the roll transition j zone reroll process for returning nuclear steam generator tubes back to service. It d.emonstrates

that rerolling tubes, with defects in the tubesheet region, is an acceptable repair technique.

l i

1 I

TABLE OF CDNTENTS 1

. Section Talt Eage ,

4 ABSTRACT iii

1.0 INTRODUCTION

1 1.1 Pumose 1 1.2 Background 1 2.0 QUALIFICATION CRITERIA 3 l

2.1 Technical Specificatica 3 2.2 Acceptance Criteria 3 3.0

SUMMARY

5

4.0 REFERENCES

9  ;

5.0 DESIGN DESCRIPTION OF REROLL AND 11 INSTALLATION EQUIPMENT 5.1 Reroll Joint Desian 11 i 5.2 Renair Of A Defective Rerolled Tube 12 5.3 Reroll Joint Installation Eculoment 12 i 5.4 ALARA Considerations 14 j 6.0 TEST PROGRAM 20 6.1 Test Matrix 20 6.2 Tests Reauired On Coupons 22

)

1 iv

l TABLE OF CONTENTS (Continued)

Section Title Page 1

7.0 TEST RESULTS 23 l l

7.1 Coupon Preparation 23 l l

7.2 Torque Development 24 7.3 Test Procedure 26 7.4 F* Coupon Results 28 7.5 EF* Counon Results 29 7.6 Tube Growth Tests 30 7.7 Roller Life 31 7.8 Discussion 31 8.0 STRUCTURAL CONSIDERATIONS 38 8.1 Reroll Joint Configuration 38 8.2 Plue And Sleeve Program Applicability 61 8.3 References 63 9.0 EDDY CURRENT EXAMINATION 64 9.1 Installation Verification 64 9.2 Rotating Probe Examination 64 10.0 EFFECT OF REROLLING ON OPERATION 65 v

l

1 4

l '

l LIST OF TABLES j.

3 , Table No. Tatin Pse

} 3-1 F* ReRollTest Matrix 7 3-2 EF* ReRollTest Matrix 8

]

i

! 7-1 F* Torque Development 25 7-2 EF* Torque Development 25 i

I- 7-3 F* Test Results 33 i

7-4 EF* Test Results 34 e

8-1 Axial Member Physical Properties- Westinghouse Series "44" 43 l-j First ReRollJoint Location Case i 8-2 Axial Member Physical Properties- Westinghouse Series "51" 44 i First ReRollJoint Location Case 4

8-3 Axial Loads in Locked Tube- Westinghouse Series "44" 45 l

First ReRollJoint Location Case l

8-4 Axial Loads in Locked Tube - Westinghouse Series "51" 46 First ReRollJoint Location Case 8-5 Axial Member Physical Properties- Westinghouse Series "44" 50 Second ReRollJoint Location Case l

8-6 Axial Member Physical Properties- Westinghouse Sedes "51" 51 l

' Second ReRollJoint Location Case 5

8-7 Axial Loads in Locked Tube- Westinghouse Series "44" 52 l

! Second ReRollJoint Location Case 8-8 Axial Loads in Locked Tube - Westinghouse Series "51" 53 Second Reroll Joint Location Case

] 4 8-9 Axial Member Properties - Westinghouse Sedes "44" and "51" 56 i

Steam Generators for the First Rerolled Joint Location Case l

without Tube Lock-up u

1 .

LIST OF TABLES (continuel) 8-10 Axial Loads in Non-Locked Tube - Westinghouse Series"44" 57 l and "51" for the First Rerolled Joint Location Case  ;

)

8-11 Axial Member Physical Properties- Westinghouse Series "44" 59 l and "51" Steam Generatorsfor the Second Reroll Joint Location Case without Tube Lock-up i 8-12 Axial Loads in Non-Locked Tube - Westinghouse Series"44" 60 and "51" for the Second Rerolled Joint Location Case 8 13 Tubesheet Ligament Stresses for Westinghouse Series "44" 62 and "51" Steam Generators at Design Conditions 1

l 1

V

4 LIST OF FIGURES Figure No. Title Pane 5-1 ReRollJoint Configuration 16 5-2 Remote ControlManipulator 17 5-3 Rotation Station And Controls 18 5-4 [ ] Tool 18 5-5 [ ] Equipment 19 5-6 Rolling Tool 19 7-1 Typical [ ] Trace 35 7-2 Typical Torque Trace- [ ] 36 7-3 TypicalTorque Trace - [ ] 37 8-1 Rerolled Tube Model And Environment 40 8-2 Tube Schematic - Series "44" Steam Generators for 41 First Reroll Joint Location Case 8-3 Tube Schematic - Series "51" Steam Generators for 42 First ReRollJoint Location Case 8-4 Tube Schematic - Series "44" Steam Generators for 48 Second Reroll Joint Location Case 8-5 Tube Schematic - Series "51" Steam Generators for 49 l Second ReRollJoint Location Case I i

i Viii

1.0 INTRODUCTION

i I

1.1 Purnose i

The purpose of this report is to provide information sufBeient to back licensed F*, EF* and L* analyses in support of a 10CFR50.59 safety evaluation allowing installation ofrerolljoints in Westinghouse-designed Series 44 and 51 steam generators with degraded tubes in the tubesheet region. His report demonstrates that reactor operation with a tube rerolljoint in the steam generator tubes will not incre.ise the probability or consequence of a postulated accident condition previously evaluated. Also it will not create the possibility of a new or different kind of accident and will not reduce the existing margin of safety.

ABB Combu.; tion Engineering (ABB-CE) provides two types ofleaktight rerolljoints for Westinghouse Series 44 and 51 steam generator tube repair. The first joint type can be located anywhere in the [

1

[ ]. Thisjoint i type was designed to be located anywhere in the [ l

}.

The steam generator tube with the rerolljoints meets the [

] of tubes which are not degraded.

Design criteria for the re- Sints were prepared to ensure that all design and licensing  ;

requirements are considereo. Analyses and testing have been performed on the tube reroll joints to demonstrate that the design criteria are met.

. The effect ofrerolljoints on steam generator heat removal capability and system flow rate are discussed in Section 10 of this report.

After the reroll joints are installed, an examination is performed using eddy current (ET) techniques. He ET examination serves as a method to verify that the rerolljoint was [

] in the steam generator tube and to assure that F*, EF* and/or L* criteria are met by the rerollprocess.

Plugs or sleeves will be installed if the reroll procedure is not successful or if there is unacceptable degradation of steam generator tubes due to the process.

1.2 Background

The operation of Pressurized Water Reactor (PWR) steam generators has, in some instances, resuhed in localized corrosive attack at the roll transition zone region and in the tubesheet crevice region of the steam generator tubing. This corrosive attack results in a localized 1

reduction in steam generator tube wall thickness. Steam generator tubing has been designed with considerable margin between the actual wall thickness and the wall thickness rerluired to l meet structura1 requirements. Thus it has not been necessary to take corrective action unless stmeturallimits are being approached.

~

Historically, the corrective action taken where steam generator tube wall degradation has been severe has been to install plugs at the inlet and outlet of the steam generator tube when the j reduction in wall thickness reached a calculated value referred to as a plugging criteria. An additional repair option has been to bridge the defect utilizing a sleeve. Eddy current (ET) examination has been used to measure steam generator tube degradation and the tube i plugging criteria accounts for ET measurement uncertainty.

Installation of steam generator tube plugs removes the heat transfer surface of the plugged tube from service and leads to a reduction in the primary coolant flow rate available for core cooling. Installation of steam generator sleeves does not significantly affect the heat transfer removal capability of the tube being sleeved and a large number of sleeves can be installed without significantly affecting primary flow rate. However, there is a minor reduction in flow rate associated with large numbers of sleeves and potential accessibility concerns as well.

The use of a tube reroll process will alleviate these concems as well as leave the tube in a condition to perform repairs at a jater time.

i 2

d

~

2.0 QUALIFICATION CRITERIA 2.1 Technical Specification Westinghouse Series 44 and 51 Steam Generators 2.1.1 Design and Operating Ratings Primary Operating / Design Temperature: 590-611/650 F  !

Primary Operating / Design Pressure: 2235/2485 psig l Secondary Operating / Design Temperature: 506-521/550 F Seconday Operating / Design Pressure: 690/1085 psig 2.1.2 Steam Generator Tube Data Tube Hole Dnlling (min./ max.): .888/.893 in.

Tube Nominal O. D.: .875 in.

Tube Nominal Wall: .050 in.

Tube Wall Reduction Due to Rolling: 4-6%

s 2.2 Acceptance Criteda The following acceptance criteria were used to assess the performance of rerolled joint  ;

coupon specimens during testmg.

2.2.S The ei;tablished torque values shall yield a [ ] percent tube wall reduction.

, These values were chosen as a means of[

i ). This range of values reflects ABB's experience in

- plug and sleeve rolling in steam generator tubes. Also, the [ ]

l accommodates the uncertainties associated with remote field applications.

2.2.2 The rerolled tube joint shall exhibit no movement relative to the tubesheet during simulation of cyclic loading conditions.-

, 2.2.3 The rerolled tubejoint shall exhibit no movement relative to the tubesheet at push test forces which represent the maximum load experienced by the tube under

! operating or accident conditions with the tube unrestrained at the support plates.

! These loads are [

4 I

I

].

3

'a . - .

4 l

4 2.2.4 The rerolled tubejoint shall exlulit [

] when subjected to secorhry side pressure levels equal to [ l

, ] the operating or upset condition pressure differential. Section 7.0 defines  ;

j the basis for the test pressure selection. l 2.2.5 The roller expander shall produce consistent rolls of bright metal surface fmish.  !

There shall be no measurable signs of wear which could effect the rolled joint over [ ], which is the proposed life of the roller expander, assuming f a planned lubricationinterval 2.2.6 Non-destructive examination techniques shall be utilized to verify that the [  !

] were properlyplaced in the tube and that F*, Elevated F* (EF*) and L* criteria were met.

2.2.7 The tube rerolljoint shall not adversely affect system flow rate or heat transfer capability of the steam generator tube.

l 4

3.0

SUMMARY

I Atotal ofI ] coupons consisting of[ ] for F* qualification and a total of[ ] coupons consisting of[ ] for EF* qualification were subjected to a rigorous qualification program. The program was designed to [

] that could be experienced during field operations. These variables 1 included the [ ]. Such conditionsinclude the [ l

]. The [ ] effective length roll expander (for reroll joints l below the tubesheet neutral axis) and the [ ] effective length roll expander (for rerolljoints l above the tubesheet neutral axis) were conservatively used to prepare all test coupons. The l complete test matrices are included as Tables 3.1 and 3.2.

l Torque values associated with a [ ] percent tube wall reduction were established using production equipment. The minimum torque value [ ] used in the test program yielded a [ ] percent tube wall reduction, and the maximum torque value [

] used inthe test program yielded a [ ] percent tube wall reduction.

The nominal value was established at [ ]. The tooling and control systems used in the test programs represent the present technology for reroll production equipment. i As technological advances are made, the updated equipment may be utilized upon completion I oflaboratoryverification.

Adhering to the test matrices, samples were prepared for testing. The samples were [ ]

l l

l

].

All samples prepared for F* Cases 1 through 5 were [

], then [ ] tested. EF* Cases 1 through 3 were [ j

], then [ ] tested. The results of these [ ] tests replicated the results obtained prior to [ ] testing.

These samples were used to determine the effect on the rolled joint of conditions expected in the steam generators, such as;the [

].

All samples prepared for F* Case 9 were [

], then [ ] tested at the above [ ] values. The results of these tests replicated the results obtained prior to [ ] testing. These samples were used to determine the effect on the rolled joint due to the maximum steam generator loading.

All F* samples were [ ], and all EF* samples were [ ]. There was [ J. Samples were also [

).

5

i Samples which had been rerolled were [ ] after completion of the rolling operation. There were no I ] of the tube due to the rerollprocess.

6

\

l

. i l

l Table 3-1 1 i

F* REROLL TEST MATRIX l

l l TESTS CASE VARIABLES NO.OF TUBE HOLE CYCLE PUSH HYDRO COUPONS 1 NOMINAL 3 MIN .888" X X X j l

l 2 MIN 3 MAX .893" X X X TORQUE 3 MAX 3 MAX .893" X X X TORQUE  ;

1 4 DRY 3 NOM .890" X X X SLUDGE 5 WET 3 NOM .890" X X X SLUDGE 6 LIFE TEST 3 NOM .890" (NOTE 1) 7 NOMINAL 3 NOM .890" X X l

8 COLLAPSE 3 NOM .890" l 9 MIN- MAX 3 NOM .890" X X X TORQUE Note 1: Test roller expanders at intervals of 50,100 and 200.

l 7

1 Table 3-2 EF* REROLL TEST MATRIX TESTS CASE VARIABLES NO.OF TUBE HOLE CYCLE PUSH HYDRO COUPONS 1 NOMINAL 1 NOM .890" X X X 2 MIN 1 MAX .893" X X X ,

TORQUE l 3 MAX 1 MIN .887" X X X TORQUE 4 DRY 1 MIN .887" X l SLUDGE 5 WET 1 NOM .890" X SLUDGE 6 COLLAPSE 2 NOM .890" 8

4.0 REFERENCES

l 4.1 Nuclear Power Business Nuclear Quality Assurance Manual, QAM-100, Fourth Edition, I Revision 4.

l

' 4.2 Quality Assurance Procedures Manual, QPM-101, Revision 0.

4.3 Quality Plan No. 2004396-QP-94-014, Rev. 00, " Project Quality Plan for the Development and Qualification of a Tube Re-Roll Process for Westinghouse Steam Generator Tubes."

4.4 STD-400-153, Rev.00, ' Test Plan for the Development and Qualification of a Steam Generator Tube Re-Roll Process for Westinghouse Series "44" and "51" Steam Generators."

l 4.5 00000-OSW-007, Rev. 00, ' Test Procedure for the Development and Qualification of a Steam Generator Tube Re-Roll Process for Westinghouse Series "44" and "51" Steam Generators."

l 4.6 Telecopy to Dave Stepnick of ABB-CE from Richard Pearson of Northern States Power, l dated December 21,1994. Design Input on F-Star /I Star Plugging Criteria.

4.7 TR-ESE-887, Rev. 00, ' Test Report for the Qualification of the Roll Transition Zone Sleeve  :

Rolled Joint for Westinghouse "D" Series Steam Generators."

]

4.8 CENC 1599, " Qualification Testing of Combustion Engineering Mechanical Tube Plug with Addendum A."

4.9 Test Report No. WO-94-205, ' Test lieport for the Additional Development and Verification of the Transition Zone Sleeve Rolled Joint for 3/4" Steam Generator Tubes."

4.10 Drawing No. C-SGN-217-458, Rev. 04, " Reroll Joint Configuration."

4.11 Qualification Report, GBRA 014 020, " Steam Generator Tube Repair by Tube Reexpansion."

(ABB Reaktor) 4.12 "Doel 2 - Tube Reexpansion, ABB Conclusions about July Demonstration," 08/13/90. (ABB Reaktor) 4.13 " Repair of SG Tubes by Rerolled Expansion - Corrosion Test."(Laborelec Labs) 4.14 Memo No. PENG-95-015, ' Testing of Steam Generator Tubesheet Reroll Samples," A. B.

Goulet to E. P. Kurdziel, dated January 23,1995.

4.15 Memo No. WO96186, ' Test Results for Re-Roll Qualification Program," D. G. Stepnick to E. P. Kurdziel, dated October 11,1996.

4.16 00000-OSW-010, Rev 00, " Test Procedure For The Life Testing Of Roll Expanders."

9

l l

4.17 TR-400-002, Rev. 00, " Test Report For The Life Testing Of Roll Expanders With Decreased l Lubrication Frequency."

4.18 Report No. A-ABBCE-9419-1119, Revision 00, " Evaluation of Tube Re-Rolling for  ;

Westinghouse Sedes 44 & 51 Steam Generators."

4.19 Specification No. 00000-OSW-009, Rev 00, " Design Specification for Re-Rolled Joints in Steam Generator Tubes."

4.20 Telecopy to Dave Stepnick of ABB-CE from Richard Pearson of Northern States Power, dated September 1,1996. Design Input on EF-Star /I Star Plugging Criteda.

4.21 Memo No. 5J177.DS, " Continuation Of Reroll Qualification Test Program," D. Stepnick to E. Pohl, dated October 1,1996.

4.22 Memo from D. Proctor to D. G. Stepnick, ' Top Of Tubesheet Reroll Collapse Test," dated September 19,1996.

4.23 Memo No. PENG-96-496, ' Testing of Steam Generator Tubesheet Reroll Samples," A. B.

Goulet to Dane Proctor, dated December 4,1996.

l 10

5.0 DESIGN DESCRIPTION OF REROLL JOINT AND INSTALLATION EQUIPMENT l 5.1 EgRg]l Joint Design Reference 4.19 contains requirements for the reroll joint and its installation. The joint becomes the [

]. The rerolljoint design is based upon the technology previously developed at ABB. Included in this category is the experience ofABB Reaktorin the areas of[

], and the experience ofABB Combustion Engineering in the areas of

]. ABB hasinstalled over [

] using rolling technology and over [ ] using similar technology. ,

The rerolljoint geometry is shown in the drawing presented in Figure 5-1. Multiple reroll joints may be used in a tube. The critical parameters conceming the joint geometry were developed by the original equipment manufacturer using F*, EF* and L* analyses. Based on these analyses,it was determined that up to [

] upon completion of the reroll would meet F* criteria. In addition, it was -

determined that up to [ ]upon completion oftheTeroll would meet EF* criteria. Per the analyses, up to [

l-Based upon information provided by utility personnel who owned and operated Series 44 and 51 steam generators, ABB-CE determined that the original hard rolllength in steam generator tubes ranged from a minimum of one and one halfinches to a maximum of two and three quarter inches. Based upon this information, ABB-CE decided to [

] from the steam generator tube end. This joint is put in place using a [

]. This geometry places the bottom edge of the rerolljoint a [ ] from the maximum height of the original roll transition.

As part of the rerolljoint, a [ ] may be performed prior to the hard roll process step. This [ ] utilizes current steam generator sleeving technology.

The [

] from the tube end and extending past the hard roll region. This process step serves a l number ofpmposes; first, to ( )

]; second, to [ ]

above the rerolljoint; and third, to [

] upon process completion.

Through the use of[ ], the tube wall reduction from the hard roll will be limited from [ ] percent minimum to [ ] percent maximum. This range of wall reduction ensures an acceptable reroll joint under the variety of conditions tested under this program.

This range ofroll expansions is [

11

j

], as well as industry experience demonstrating this range I to provide optimum structuralintegrity for hard rolled joints.

5.2 Renair Of A Defective Rerolled Tube If a tube is found to have an unacceptable rerolledjoint, the [

] above the first reroll. When [ multiple rerolljoints] are unacceptable or not possible, the tube can be sleeved in order to keep it in service or it can be taken out of service with ,

standard mechanical tube plugs at both ends of the tube. In either case, approved methods to I perform the processes are in place.

5.3 Reroll Joint Installation Equioment The equipment used for the remote installation ofrerolled joints in a steam generator is made l up ofthe following basic systems: l

1. Remote Controlled Manipulator

2. Rotation Station l

3. Tube [ ] Equipment l

4. Tube [ ] Equipment ,

5. Tube Rolling Equipment

6. Tube Eddy Current Equipment These systems, when used together, allow installation ofthe rerolljointswithout entering the l

steam generator. In this way, personnel exposure to radiation is held to a minimum.

The tooling and methods described in the following sections represent the present technology for rerolled joint installation. As technological advances are made in the installation process, the updated techniques may be utilized upon completion oflaboratory verification by ABB-CE.

5.3.1 Remote Controlled Manipulator The remote controlled manipulator (Figure 5-2) serves as a transport vehicle for repair and inspection inside a steam generator hot leg or cold leg plenum.

The manipulator consists of two major components; the manipulator leg and the manipulator arm. The manipulator leg is installed between the tubesheet and the bottom of the primary head and provides axial (vertical) movement of the arm.

The manipulator arm is divided into the head arm, probe arm and swivel arm.

Each arm is moved independently with encoder position controlled electric motors. The swivel arm allows motion for tool alignment in various types of tube 12

pitches. Computer control of the manipulator allows the operator to move tools from outside the manway and accurately position them under the proper tube against the tubesheet.

5.3.2 Rotation Station The rotation station (Figure 5-3) mounts on the end of the manipulator arm through the use of a locking dovetail arrangement. The rotation station delivers the various tools required for the reroll operation to the proper location. Cameras mounted on the rotation station are used to verify location as well as aid in the entry of tools into the tube. Proper elevations for the various tools are obtained through the use of hardstops. The rotation station also provides controlled rotation to some of the tools used in the reroll operation. The station is controlled through the use of a torque monitoring system, which trips the station offwhen the preset torque value is reached.

5.33 TubeI ] Equipment The initial step in the reroll process involves [

] (Figure 5-4), or equivalent. The purpose of this step

.is to { ] during power plant operation. The [

). Additionally, the [

, ]. An air motor rotates the [ ] as it is inserted into the end of the tube. At the appropriate elevation, the toolis [

). An interference fit between the tube and the [ ] upon completion ofthis process step.

5.3.4 ' Tube [ ] Equipment When applicable, the [ ] equipment (Figure 5-5) is used to minimin the amount of crevice products between the tube and tubesheet [

] the steam generator tube. The [

]. When the [

). A tool hardstop is provided for proper tool vertical positioning.

The [

] prior to use. The [ ] signalis fed back to the display screen's strip chart recorder in order to record the [

1 An[ ] is utilized to move the [

] away from 13

a ..

}

t the area. This [ ] of i

thejoint and no credit is taken during analysis ofthejoint.

1 i The [ ] may be used with any of the rerolljoints (Figure 5-1).

l However, due to equipment reachability and tube access concerns, it is typically used only on the lower two reroll elevations.

5.3.5 Tube Rohg Equipment He tube rolling equipment (Figure 5-6) is used to expand the tube into intimate contact with the tubesheet, forming a strong leaktight joint. He rohg tool is .

positioned under the proper tube using the manipulator, which is then used to insert the toolinto the tube. The rohg tool utilizes a hardstop to position it

! verticallyin the properlocation.

i i

j The rolling equipment consists of the air motor, tube expander, torque readout

! and torque calibration unit. The torque readout and settings of the rolling tool

are verified on the torque calibration unit prior to rohg of the tube. The tube is

! expanded to a torque which has been demonstrated by testing to provide a i leaktight joint. The torque trace appears on the display screen's strip chart i recorder and is used .for evaluation of the rohg process on the individual tubes.

! The torque trace is used as the official record of the process. A second rollis l performed to verifythe torque level reached on the first reroll. The evaluation of l the torque trace is the basis for acceptance or rejection of the rerolljoint since the l joint integrity is based on percent wall thinning. A rolled joint which fails to meet l the acceptance criteria may be rerolled. [

I* ,

i l 5.3.6 TubeEddy CurrentEquipment <

l l After the reroll joints are installed, an examination is performed using eddy ,

current (ET) techniques. The ET examination serves as a method to verify that j the rerolljoint was [ ] in the steam generator tube ,

4 and to assure that F*, EF* and/or L* criteria are met by the reroll process.  !

i l 5.4 ALARA Considerations i

l He steam generator repair operation is desigred to minimin personnel exposure during re-i roll operations. The manipulator is installed from the manway without entering the steam

j generator. It is operated remotely from a control station outside the containment building.

1 The positioning accuracy ofthe manipulator is such that it can be remotely positioned without i having to install templates in the steam generator.

The rotation station is designed so that the dovetail fitting quickly attaches to the manipulator.

The rotation station is designed to qu ckly engere the individual rerolling tools. The tools are i

l simple in design and all operations are performed remotely using tools held by the

manipulator. Each tool can be changed at the manway in 10-15 seconds. A tool operation is 3

14

- . , , , , _ - - . . - . - .,_m .

- -r - - .- ... . .

performed on several tubes rather than performing each tool operation on the same tube before proceeding to the next tube. This reduces the number of tool changes which are required. If tool repair is necessary, the toolis removed and reroll operations continue using a spare tool. Tool repair is completed off the platform in a low radiation area.

Air, water and electrical supply lines for tooling are designed and maintained so that they do not become entangled during operation. This minimius personnel exposure on the steam generator platform. All equipment is operated from outside the containment building.

In summary, the steam generator operation is designed to minimin personnel exposure to ionizing radiation and is in full compliance with ALARA standards.

l l

l 15

. . . - . - . . . . _ . . - - - . - - . _.-..- __ . . . - . - . - . . . - - - - _ . - . - ~ . . - . . . - . . -

2 .

J 4

4

. +

1 e

4 I

j-  :

1 4

)

4 d

J 5

s i

i i

i.

4 1

4 J

J

.f 1

],

4 il i

i t

t

]

4 e

4 j

e 4

4

}

4 4

t 4

(

i s

1 1-s 3

1 i

1-a 4

t I

Figure 5-1 ReRollJoint Configuration a

i 16

{ .- -- _ - .

i l

l

\

l l

l 1

l l

1 Figure 5-2 l.

17

i 1 .

J 3.,

s 1

i n

1 b

1

?

.I i

i 4

19 4

1 i

i 1

a T

(

N s

.d 1

i v.

J L

t i

i 1

s 1

1 j

Figure 5-3

?

4 i

5 4

e a

t 1

1 i

A s

4 1

1-1 1

1

.1 1

)

i i

1 i Figure 5-4 I

a 18

. _ - . . . . . . .. - .= - .

. -.- ... ~ . . . . . _ - - - _ . . - - . . . _ _ . - . - - - - - - . - - . - _ . - .

1 1

I

.I t

l t

Figure 5-5 Figure 5-6 19

i.

! 6.0 TEST PROGRAM i

l 6.1 Test Matrix Two test matrices were developed to test the reroll joint over a range of test conditions.

j These matrices are shown in Tables 3-1 and 3-2. The matrices represent a range of l conditions to which the rerolled joint was tested. A total of [ ] coupons were tested for

each test case for the F* program. A total of[ ] coupon was tested for each test case for

the EF* program. A description of each of the test conditions and type of tests is given below.

! 6.1.1 Tube Dimensions

Two heats ofInconel 600 tubing were used in this program. The heat numbers are[ ], purchased from Sandvik Steel Co.(F* program), and { ],

l

purchased from Valinox T ... aire (EF* program). The tubing was purchased to l nominal dimension of .875" O.D. x .050" wall, however, the tube wall j dimensions were not uniform, varying from a minimum of[

l

]. This was accounted for in the measurement step of sample j preparation.

6.1.2 Tube [ ] Size ,

4

A[ ] sizes was tested in the reroll program. This range of i [ ] sizes represents actual tubesheet [ ] sizes per the original i equipment manufacturer's specification. The [ ] sizes tested were the

[ ). 3

, Changesin [ ] affect the amount of wall thinning the tube will experience l and require that the roller expander perform consistently over a [ ).

_F* Program l Test Case 1 performed the rerollin a [

! . Test Cases 2 and 3 performed the rerollin [

]. The remaining test cases were

' ] torque was defmed as that performed in a nominal size tube hole. [

torque required to produce approximately [ ] percent wallthinning and j [ ] torque as that torque required to produce approximately [ ]

percent wallthinning.

i 1

j EF* Program j

Test Case 1 performed the rerollin a [

]. Test Cases 2 and 3 performed the rerollin [

].

20

N rface Finish 6.1.3 Tha tube holes for this program were bored to produce a surface finish of [ ]

RMS. 7he tubes were purchased to a [ ] RMS outside diameter sudace finish and wue received with a [ ] RMS finish. These variables were constant throughout the test program.

6.1.4 Torque Setting A[ ] setting was developed as pr., of this program. As described earlier, these settings are defined as the torque required to produce approximately [ ] percent tube wall thinning. Test Cases 2 and 3 ofthe F* program performed the reroll using a [

] percent wall thinning. These rerolls were performed in [ ]in order to force th: rollers [

]. Test Cases 2 and 3 of the EF* program also performed the reroll using [ ] percent wall thinning. However,the [ ] were used to bracket the test results.

6.1.5 [ ] Conditions The possib2ity exists that [

] during rerolling operations. [

] prior to performing the reroll. Test Cases 4,5 and 8 of the F* program simulated these conditions. A [

] for Test Cases 4 and 8. This same [

] was performed. This extra preparation step assured a

[ ). Test Cases 4,5 and 8 of the EF*

program also simulated these conditions. l

[

].

6.1.6 Roller Expander Roller expander geometry is a constant with the [

]. This roller expander geometry is based upon experience gained in plug and sleeve installation programs. The [ ] effective length roll l expander was used to prepare all test coupons for the F* program, while the [ ]

effective length roll expander was used to prepare all test coupons for the EF*

program.

21

. . . . . -. . ~ . -

, .l

' j

< 1 j 6.2 Tests Reauired On Coupons I The test procedure requires a [ ] test after rerolling the tube into the block.

I Upon completion of the [ ] test, the coupons were subjected to [ I l

] tests, after which the coupons were [ ] tested a second time. The

[ ] tests were performed from the [ ] in order to increase the J conse:vatism of the test. A [ ] test was also performed in order i to conform to the requirements of Reg. Guide 1.121. Finally, the coupons were subjected to a[ ] at whichjoint movement occurs.

4 i

1 L

)

v

]

i ,

1 \

l 22

4 i

1' i

7.0 TEST RESULTS i

f 7.1 Conoon Preparation i 1 j Mock tubesheets were machined with [ ] as defined in the test matrix.

l Additionally, a split block whh a nominal hole size was machined. This block was used to

! develop the torque range required to meet the acceptance cdteria.

I

! 7.1.1 Tube Installation  :

Steam generator tubes were cut to six inch lengths and rolled into the tubesheet  :

blocks at the lower end of the blocks. This was done to anchor the tube in the block and to simulate the originalhard roll If the particular coupons required ,

]

[ ] conditions, the [ ] onto both the tube outside surface j and the tube hole inside surface prior to locking the tube in place. Measurements i required for tube wall reduction calculations were taken prior to instahg the j tube into the block.

) 7.1.2 Tube [ ]

i i The tube [ ]. The

coupons were placed in a test stand and the rotation station was used to perform j the [ ]. The[

i ).

7.1.3 Tube [ ]

1 t Where applicable, the tubes were [

! ] descdbed earlier. The [

! ]. The use of a [ ] for testing will l uot detrimentally affect the use of a [ ] dudng the field effort. An

! [ ] was used to [ ] into i

! the block. A typical [ ] trace, as recorded on the strip chart, is shown in )

j Figure 7-1.

i j 7.1.4 Tube ReRohg 1

The rerohg operation was performed by fixtudng the coupon into a rohg stand. The [ ] roll expander was conservatively used for all rerohg tests.

He test matrix defined the [ ] that were required for coupon preparation. A typical torque trace, as recorded on the strip chart (torque is along the Y-axis, while time is along the X-axis), is shown in Figure 7-2 for a coupon prepared with [ ]. The [

] and there is a smooth, steady increase in torque.

A typical torque trace, as recorded on the strip chart, is shown in Figure 7-3 for a coupon prepared with [ ].The[

23 l

J

l l

] during the rolling operation. The torque setpoint is reached over a much longer period of time.

7.1.5 Coupon Numbering The following numbering system was used to identify the coupons. l F* Pronram .

i B1,B2,B3 Case 1 [ ] ,

A1,A2,A3 Case 2 [ ]

A4,A5,A6 Case 3 [ ]

C1,C2,C3 Case 4 [ ]

C4,C5,C6 Case 5 [ ]

D1,D2,D3 Case 7 [ ]

El,E2,E3 Case 8 [ ] r F1,F2,F3 Case 9 [ ]

i EF* Program i i'

110-3 Case 1 [ ]

90-4 Case 2 [ ] ,

140-3 Case 3 [ ]  !

90-5 Case 4 [ ]  !

110-4 Case 5 [ ] l 130-1,130-2 Case 6. [ ]

i 7.2 Toraue Development  ;

The first step in the program was to develop torque levels associated with tube wall thinning l of[, ] percent. This was done by using the split block arrangement. Tubes were i placed in the split block, rolled, then measured to determine wallthinning. Tables 7-1 and 7-2 give the values for the various torques using the [ ] effective length roll for the F*

program and the [ ] effective length roll for the EF* program.

Based upon this information, maximum and minimum torque values were first chosen for the

[ ] effective length rolls. These values were [ ] for the minimum torque setpoint, [ ] for the nominal torque setpoint and [ ] for the maxinmm torque setpoint. These were the torque settings that were utilized during the testing process.

Additionally, a test coupon was rolled to the system limited (based on supply air) torque value of[ ] This sample, with a wall thinning of[ ], successfully passed [

] testing.

24

d Table 7 F* Data Torque (in-lbs) Wall Thinnine (%) Torque (in-lbs) Wall Thinning (%)

74 2.43 138 5.59 74 1.61 130 4.66 89 2.21 131 5.83 87 3.21 139 4.60 85 3.81 145 5.12 88 2.84 144 4.54 109 2.53 153 7.58 102 3.25 153 7.41 113 3.82 154 6.67 115 4.03 168 7.68 116 4.82 167 7.28 111 4.50 167 7.68 135 3.85 199 9.39 Table 7 EF* Data Torque (in-lbs) Wall Thinninn (%) Torque (in-lbs) Wall'Rinninn (%)

95 3.41 136 3.64 97 4.02 137 7.71 100 4.77 153 4.00 102 5.56 161 4.28 112 3.66 166 4.55 112 5.20 173 5.99 120 5.12 174 5.48 126 4.09 175 7.03 129 5.10 177 4.44 135 6.66 185 5.85 25

7.3 Test Procedure Reference 4.5 is the detailed procedure describing all step-by-step activity for the test program. This section summarizes the procedure used to conduct the various tests on the coupons. Tables 7-3 and 7-4, at the end of this section, summarize all of the test results.

7.3.1 [ ] Tests Normal operating and postulated accident conditions [

] on the steam generator tube and tubesheet. The maximum tubesheet loadings result from a flexure pattern where tubesheet ligament stress across the majority of the tubesheet is tensile above the neutral axis and compressive below the neutral axis. For reroll joints below the . neutral axis, the compressive stress would tend to close the tubesheet hole during operating conditions, thus increasing the tube to tubesheet joint contact pressure.

For rerolljoints above the neutral axis, the tensile stress could open the tubesheet hole dudng operating conditions, thus potentially reducing the tube to tubesheet joint contact pressure. An extensive test and qualification program on the Roll Transition Zone Sleeve rolledjoint (Reference 4.7), has shown that the tubesheet flexure has no effect on the joint structural integdty or leak tightness. Therefore, only axialloads were applied to test coupons during the rerolljoint cyclic test program.

The rerolled joints were subjected to a cyclic axial load test to demonstrate structural capability of the joint. The loads used for the cyclic tests were based upon the operating loads. experienced by a tube [ ], as this was the worst case loading condition on the tubes. These loads are [

]. Section 8 provides an analysis of this condition. The loading was applied to these rerolled joint at [ ]using an MTS Testing Machine. [

l.

All coupons prepared for F* Cases ~ 1 through 5 were [

]. The rerolled joints for F* test Case 9 were conservativelyloaded between [ ] for a total of[ ]

cycles. Coupons prepared for EF* Cases 1 through 3 were [

]. [

]. These samples were used to determine the effect on the rolledjoint due to conditions expected in the steam generators, such as; the [

1 26

l 7.3.2 [ ] Tests As described in the previous section, steam generator tubes are subjected to (

loading conditions while in operation. The maximum loads to which the tube is subjected are [

). The rerolled coupons were push tested to a load of[ ] for ,

1 the F* coupons and [ ] for the EF* coupons using an MTS Testing Machine. Coupons from F* Cases 1 through 5 and EF* Cases 1 through 3 ,

exhibited [ ] at this load and the test was terminated. Coupons from i F* Cases 7 and 9 were pushed to failure. The failure occurred due to tube buckling at a load of[ ];the rerolledjoint did not [ ).

7.3.3 [ ] Tests l l

[ ] tests were performed on the coupons before and after [ ]

testing. The tests were performed from the secondary side in order to increase l the conservatism ofthe test. The test was performed at [

]. The first pressure level represents a secondary side test.

The ASME Code hydrostatic test pressure of:

1.25 x Primary Design Pressure = 1.25 x 2485 psi = 3106 psi is the basis for the first primary side pressure level. Rerolled joints passing the test at this pressure are considered acceptable. For added conservatism, ABB-CE increased the pressure [ ] above the acceptance criteria. This represents a factor of safety of over [ ] for the test.

All samples except the samples [ ] exhibited leaktightness.

Samples C1,C2 and C3 had an [

].

In order to comply with the guidelines of Regulatory Guide 1.121, which call for a test pressure of three times the operating differential, F* Test Case 7 coupons were pressurized to [ ] fromthe primary side. [

].

7.3.4 Collapse Tests The possibility exists that sludge will be present in the annulus between the tube and tubesheet during rerolling operations. The moisture in wet sludge, trapped between two rerolledjoints, has the potential of flashing to steam under operating temperatures. He pressure build up during this event will be released either 27

4- 4 & ~ - 4-.- * - . - - + k 4 m## _ A - _a_ w+ +h4 .44L di A > .-P>- -

1 .

j through the rolled joints or by a collapse of the tube. [

1

].

j 7.4 F* Coupon Results j Test Case 1 - [ ]

Coupons B1,B2 and B3 of this test case successfully passed all phases of testing.

[

t

].

I Test Case 2 - [ ]

I t Coupons A1, A2 and A3 of this test case successfully passed all phases of testing.

[

i

].

1 Test Case 3 - [ ]

Coupons A4, A5 and A6 of this test case successfully passed all phases of testing.

1 I

[

]-

! Test Case 4 - [ ]

(

l Coupons C1, C2 and C3 of this test case successfully passed all phase of testing.

i i I i

i ).

Test Case 5 - [ ]

];

Coupons C4, C5 and C6 ofthis test case successfully passed all phases of testing.

4 I

].

. Test Case 6 - [ ]

See Section 7.7 for the results ofthe roller life test.

s 4

4 28 4

Test Case 7 - [ ]

Coupons D1, D2 and D3 of this test case successfully passed the push tests and the piimary side hydrostaticleak test.

(

1

! Test Case 8 - [ ] 1 f

l I 1

l

[

1 I

1 Test Case 9 - [ ]

Coupons F1, F2 and F3 of this test case successfully passed all phases of testing.

I 1

7.5 EF* Coupon Results Test Case 1 - [ ]

Corpon 110-3 ofthis test case successfully passed all phases of testing.

I

].

Test Case 2 - [ ]

i Coupon 90-4 ofthis test case successfully passed all phases of testing.

1 29

~

[

].

(

j Test Case 3 - [ ]

i Coupon 140-3 of this test case successfully passed all phases oftesting.

2

[

1 Test Case 4 - [ ]

Coupon 90-5 ofthis test case succes'sfully passed all phases of testing.

I J.

Test Case 5 - [ ]

Coupon 110-4 of this test case successfully passed all phases oftesting.

I 1

Test Case 6 - [ ] ,

1 I

1 1

I 1

7.6 Tube Growth Tests An additional area of concern was the area of steam generator tube growth or contraction during the rerolling operation. Three coupons were prepared and measured prior to the rerolling operation. The samples were then [

), a length which represents the amount of unrolled tube that will be

[ ] in the steam generators. The coupons were then subject to a torque that resulted in [ ] percent wall thinning. The results are shown below.

30

Tube No. InitialLength ] [ ] Change

[

1 6.060" [ ] [ ] [ ]

2 6.068" [ ] [ ] [ -)

3 6.069" [ ] [ ] [ ]

The change in length due to the [ ] and the length change due to the [

], for an overalllength change of, on average, l ].

7.7 Roller Life ABB-CE has a large volume of experience with rolling operations. References 4.16 and 4.17 document life testing performed on roller expanders during sleeve roll qualification testing.

This data is applicable to the cmrent program, since similar roller designs are employed and similar materials are involved. In both of the referenced programs, there was no evidence of detrimental wear beyond burnishing marks and a slight change in color on the mandrel and rolls. [

].

7.8 Ditcussion Torque values associated with tube wall thinning of[ ] were established using production rolling equipment. These values were established by rolling tube samples in a split block and recording the torque trace. The tubes were then removed from the block, sectioned and measured to determine wall thinning. Based upon the acceptance criteda established, which bracketed original equipment manufactunng cdteria and reflected ABB-CE rolling experience, torque values for the [ ] and [ ] effective length rollers in the range of[ ] were established.

Using the torque values established, the tests called out in the test matrices were performed.

All samples were prepared using a production control system and tooling. All [ ]

coupons, representing various steam generator conditions, were . tested and met the acceptance criteda. The low torque coupon (Al-A3) preparation resulted in torques above i

the minimum value of[ J. This occurred due to an overshoot of the intended valuebythe system. However,it still resulted in a lowwallthinningvalue of approximately

[ ] percent.

Cyclicload ranges of[ ] and [ ] were used to test both the ,

i P and EF* coupons for a total of[ ]. The load values were based on the worst case loading that the tube would expedence(depending upon location in the tubesheet) and i cycling the tube through the total amount of load cycles the tube experiences during j operation, regardless of loading conditions. This approach assures a high degree of conservatism. Under these loading conditions, [

].

31

1 .

o l A push test load of[ ] was applied to all of the rerolljoint coupons. This value represents a load greater than the maximum tube loading conditions desented earlier. The tests were stopped beforejoint failure was observed. [

i ). As an additional test, six coupons j ,

were pushed to failure. Failure occurred by tube buckling at [ ].

Hydrostatic leak tests were performed on all coupons before and after cyclic loading. The test i pressures represented a secondary side hydrostatic test and a primary side hydrostatic test.

I All tests were performed from the secondary side of the coupons, which represents a high

. degree ofconservatism. The ASME Code hydrostatic test pressure of[

]. An additional [ ] was then applied to increase j

the factor ofsafety further. [ ] coupons were tested from the primary side at a pressure of[ ). This represents a pressure greater than the three times operating differential pres. cure set forth in Regulatory Guide 1.121.

All coupons held pressure for a [ ] mimmum at each pressure level with no observable leakage except for the coupons with [ ].

These coupons exhibited an [

]. [

1 I

1 32

i 1

Table 7-3 F* Test Results 33 1

i

_ . _ _ . . . _ . _ . _ _ . . _ _ . . . _ . _ _ _ _ _ . _ . _ . . . . . . . . _ _ . _ _ . . ~ - . . _ . _ . . _ . . . . . _ _ _ _ _ . _ . . _

i.

4 i*

T

}

r I

I

)

t

/

Table 7-4 i EF* Test Results i

34

i

. i 1

. i.

4 4

i t - ,

6 l h

d t .

i e

a

.1 i

4 1 ,

1 0

} F k

1 i

9 4

ia 4

L i i i

2> r 4

4 >

d 1

J i

i 1

i I

Figure 7-1 Typical [ ] Trace 35

4 I

i Figure 7-2 Typical Torque Trace - [ ] Sample 36

/

Figure 7-3 TypicalTorque Trace - [ } Sample 37

.- .. ~_ -- - . . - - ._-. __ . - -. - - -. - -. . - . - . - - - . . . = .

! 8.0 STRUCTURAL CONSIDERATIONS

! An analysis was performed to generate conservatively high loads to be used in the test

! program discussed in Section 7.0. The " worst" case loading condition was found to be for [

1 i .

l.

The operating and design conditions for all of the Westinghouse Series 44 and 51 plants (Reference 8.3.1) are considered. Only the " worst" case operating / design conditions for each of the Series 44 and 51 steam generators are used in the analysis. This analysis addresses [ L

] cases. In the first case the [

] for the Series 44 and 51 units, respectively. In the second case the [

] allowed per Reference 8.3.2. A structural evaluation for the re-rolled tube geometry is modeled in Figure 81.

8.1 Reroll Joint Configuration 8.1.1 Axial Loading for the First Rerolled Joint Case with [ ] .

The rerolled tube schematics for both the Westinghouse Series 44 and 51 steam generators are shown in Figures 8-2 and 8-3, respectively, for the first location case. t The rerolledjoint is [

] for the Series 44 and 51 units, respectively. The structural modelis a system of axial members with properties and boundaries as sbown in Tables 8-1 and 8-2 for Series 44 and 51 steam generators, respectively. The [

] come from Reference 8.3.6. The axialload on the rerolled tube is due to the [

1 From Figure 8-1, [

l I

l-Therefore, from Table 2, page 5-70, of Reference 8.3.4; the total spring stiffness for the lower and upper tube in series is:

38

[ ]

From equation 15.142, page 15-27, of Reference 8.3.5; the [

] are:

I l I 1 From the modelin Figure 8-1, the forced tube displacement,Srm.a, due to temperature is:

I l Also, from equation 15.142, page 15-27, of Reference 8.3.5; the axial load, F, is:

I l The calculations from the above equations result in a [

] for the Series 44 and 51 steam generators, respectively, due to [

]. The results are tabulated in Tables 8-3 and 8-4.

i 39

) -

1 1

t e

J

'l 4

4 I

7 7

4 4, .

Y

.i k

4 1

f a

1 9

1 1

i Figure 8-1 Rerolled Tube Model and Environment 40

- t i

i 5

P i

I i

{

l Figure 8-2 Tabe Schematic - Series "44" Steam Generators for the First Rerolled Joint Location Case 41

9 e

Figure 8-3 Tube Schematic - Series "51" Steam Generators for the First RcRolled Joint Location Case 42

l l

i; i

f 1

i Table 8-1 r

Axial Member Physical Properties - Westinghouse Series "44" Steam Generators -l for I, the First Rerolled Joint Location Case with Tube Lock-up r

i i

i t

I f

t

.I 1

[

l f

I L

43 l t

Table 8-2 Axial Member Physical Properties - Westinghouse Series "51" Steam Generators for the First Rerolled Joint Location Case with Tube Lock-up 44

s r

t o

a r

e n

e G

m a

t e

S

" e s

4 a 4 C "s n i

e i o

r t e a S c e o s L 3 u t n

8

- o i h o .

e groJ l

b i t

nf de a s T

l e l o

W- R e e R b t s

u r T i F

d e e k ht c

o L

i n

s 5 d 4 a

o L

l i

a x

A

Table 8-4

, Axial Loads in Locked Tube - Westinghouse Series "51" Steam Generators for the First Rerolled Joint Location Case 1

i 46 l

3 e

8.1.2 Axial Loading for the Second ReR.olled Joint Location Case The rerolled tube schematics for both J ; Westinghouse Series 44 and 51 steam generators are shown in Figures 8-4 and 8-5, respectively, for the second rerolled location case. The rerolledjoint is [

] for both series steam generators. The stmetural model is a system of axial members with properties and boundaries as shown in Tables 8-5 and 8-6 for Series 44 and 51 steam generators, respectively. The [

]

come from Reference 8.3.6. The axialload on the rerolled tube is due only to the [ ] between Points A and B.

The calculations use the same equations that are detailed in Section 8.1.1 and result in a 1

]. The results are tabulated in Tables 8-7 and 8-8.

l l

l l

l 47

6 1

l Figure 8-4 Tube Schematic - Series "44" Steam Generators for the Second Rerolled Joint Location Case 48

t

\

l l

Figure 8-5 Tube Schematic - Series "51" Steam Generators for the Second Rerolled Joint Location Case 49

Table 8-5 Axial Member Physical Properties - Westinghouse Series "44" Steam Generators for

• the Second Rerolled Joint Location Case with Tube Lock-up 50

Table 8-6 Axial Member Physical Properties - Westinghouse Series "51" Steam Generators for -

the Second Rerolled Joint Location Case with Tube Lock-up r

51 .

- . - - . - - .......-.-_------.u.. - _ . - - _ . _ -_ _ - - . _ . - - _ _ _ _ _ _ . _ - _ _ . _ - _ - _ _ _ . -_. ~ , . - - - - - -+ -~ ~~ -m ._ - --__- _ _-- - -- _. - w

sr t

o a _

r _

e .

n .

e .

G _

m a

t e

S e s _

a _

4" C _

4 _

" n s i o .

e t _

i r a _

e c S o e L s t 7- u i n

8 o o hgr J e

l b i t

nf odel a s l T e o Re W - R e d b

u n o

T c e

d S e

k e c

o ht L

i n

s 2 d 5 a

o L

l i

a x

A

sr t

o -

a r

e n

e G -

m a

t e

S e ,

" s a

1 5 C

" n s o i

e i t

r a e c S o e L s t 8 u n 8

- o i o

hgrJ e

l b i nfode t

a s l

l T e o W Re 3 .

- R 5 e d b n -

u o T c d e e S k e c ht o

L i

n .

s d

a o -

L l

i a ,

x A ,

a w

8.1.3 Axial Loading for the First Rerolled Joint Case with No Tube 1ock-up i~

The rerolled tube schematics for both the Westinghouse Series 44 and 51 steam l generators are shown in Figures 8-2 and 8-3, respectively, for the first location case, j The zerolledjoint is

] for the Series 44 and 51 units, respectively. The structural modelis a system of axial members with properties and boundaries as shown in Table 8-9 for

, Series 44 and 51 steam generators. The [

i

] come from Reference 8.3.6.

The maximum axialload on the rerolled tube is obtained when it is [

).

i

] From Figure 8-1, at Point A, [

i i

1 From equation 15.142, page 15-27, ofReference 8.3.5; [

]is:

I 1 From the modelin Figure 8-1, the [ l

] is:

I 1 Also, from equation 15.142, page 15-27, of Reference 8.3.5; the axialload, [

]is:

[ ]

I 54

0

'Ibe axialload, [ ] is-I }

where:

l P2and P are i the Secondary and Primary Pressures, respectively.

R. and R; are the outer and inner tube radii, respealvely. l Therefore, the total axialload, F, is:

l }  !

l The calculations from the above equations result in a {

l

]. For the [

J. for the Series 44 and 51 steam generators, respectively. The results are j tabulated in Table 8-10.

l l

i i

55

- .. . - . - . . . _ . ~ . . . . . . . . - . - . - . _ . . _ . - . . _ . . . . . . . . _ . . . . - . . . .. . . . . . -

6 Table 8-9 t

i Axial Member Physical Properties - Westinghouse Series "44" and "$ 1" Steam Generators for  !

the First Rerolled Joint Location Case without Tube Lock-up b

. I 9

j i

b P

5

?

~

i b

f I

I t

?

l f

r 6

I i

b 56 i.

i l

t a

Table 8-10 Axial Loads in Non-Locked Tube - Westinghotise Series "44" and "51" Steam Generators

. for the First Rerolled Joint Location Case 57 ,

se

_ _ _ _ _ _ _ _ . , _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ . _ _ _ _ _ _ . _ _ . -_ _ _ _ _ _ _ . _ _, , ,- ~ ..-----e . - , , , , , _ - _ - _ _ _ . _ ___ _ _ _ _ _ .

. ~ . _ _ . _ . _ _ _ _ ,-_ . . - . . _ . _ . ._ __. . ._. _ _ _ .. . _ - _ . . _ . . . . _ . . . _ _ . _ _

f ,

l*.

i 8.1.4 Axial Loading for the Second Rerolled Joint Case with [ ]

'Ibe Terolled tube schematics for both the Westinghouse Series 44 and 51 steam i generators are shown in Figures 8-4 and 8-5, respectively, for the second rerolled location case. The rerolledjoint is [ ] for

~

both series steam generators. The structural model is a system of axial members with propdrties and boundaries as shown in Table 8-11 for Series 44 and 51 steam i

generators. The [

! ] come from Reference 8.3.6. The maximum axialload on the rerolled tube is obtained when it is [ ].

The calculations use the same equatious that are detailed in Section 8.1.3 and result in a [ ]

for the Series 44 and 51 steam generators, respectively, at [ ].

For the [

j ] for the Series 44 and 51 steam

( generators, respectively. The results are tabulated in Table 8-12.

i i

i e i

1

)

J e

i i

i i

58

Table 8-11  ;

Axial Member Physical Properties - Westinghouse Series "44" and "$1" Steam Generators for  !

the Second Rerolled Joint Location Case without Tube Lock-up i l

b t

i I

f r

t

{

1 t

h i

59 t

. m. >

7

= - - . . _ . . _ _ _ . . _ _ _ _ . . . . . .

.i Table 8-12  !

Axial Loads in Non-Locked Tube - Westinghouse Series "44" and "$ 1" Steam Generators for  ;

the Second Rerolled Joint Location Case t

i I

i f

s t

o

?

f t

t A

P h

l I

'I1 i

I L

k r

t L

60

i '

8.1.5 Tubesheet Ligament Stresses  ;

[

l' In calculating the tubesheet ligament stresses for the Westinghouse Series 44 and 51 steam generators; the tubesheet ligament stresses in Reference 8.3.3 for a Series 44 j j are used as a basis for determining these stresses acting on the rerolled tube joint.

' ]

These tubesheet ligament stresses are also applicable to the Series 51 steam <

generators based on the following observations.

I 1. [

• l l

, 2. [

1

! 3. { j 1  !

i

! I i

f

]:

I l The tubesheet ligament stress results at the design condition for various rerolled locations are tabulated in Table 8-13.

I l 8.2 Plug and Sleeve Program Applicabilily As previously discussed, ABB/CE has extensive experience in the area of rolling. The mechanical plug rolling program and the advanced sleeve rolling program both utilize torque !evels similar to those developed for the tube reroll program. Numerous analyses and test programs have been performed to support the plug and sleeve installation processes. Discussions of these programs can be found in References 4.7 and 4.8 that were mentioned in Reference 8.3.7.

61

i .

e Table 8-13 Tubesheet Ligament Stresses for Westinghouse Series "44" and "$1" Steam Generators at Design Condition h

j I

L i

i l

l l

1 l

i 62

8.3 References 8.3.1 Westinghouse Steam Generator Standard Information Package, January 04, 1982 (REF-96-002).

~

8.3.2 Northern States Power Co. (Richard P. Pearson) Fax to ABB/CE (Dave Stepnick), dated 9/09/96.

8.3.3 " Primary / Secondary Boundary Components Steady State Stress Evaluation",

prepared by P. Wedler, Westinghouse Electric Corp., April 1965 (REF-96-001).

'i 8.3.4 Mark's " Standard Handbook for Mechanical Engineering", 8th Edition,1979.

8.3.5 " Mechanical Engineering Reference Mar;;al", by Michael R. Lindeberg, P.E.,

9th Edition,1994.

8.3.6 ASME Boiler and Pressure Vessel Code,Section III for Nuclear Power Plant Components,1986 edition, no addenda.

8.3.7 ABB/CE Report No. CEN-620-P, Revision 01-P, " Series 44 & 51 Design Steam Generator Tube Repair Using a Tube Re-Rolling Technique", April 1995.

8.3.8 Westinghouse Report No. WCAP-14225, Revision 1, Table 2-3.

63

J i

,v/

1 i

l 9.0 EDDY CURRENT EXAMINATION I

9.1 Installation Verification l ,

Upon completion ofthe re-rollprocess, an eddy current technique, using a [

],is employed to verify that the [

] have been placed in the proper location in the tube.

9.2 Rotatine Probe Examination Upon completion of the installation, an [ ], or equivalent, is pulled through the rerolled tube to detect tube indications. Since the parent tube, with known ECT indications,has been worked with [

], an inspection is necessary to determine if the original indications have changed. The [

] results will be compared with previous test results in order to determine whether or not the odginalindications have propagated. 'Ihis test will be used to verify that the F* and L* criteda of undegraded hard roll tube length above previous indications are met.

I 64 l

l *,

. L .,.

10.0 EFFECT OF RE-ROLLING ON OPERATION i

I  !

! 1 J.  !

a 65

.