ML20084G789
| ML20084G789 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 03/31/1983 |
| From: | Johari Moore BABCOCK & WILCOX CO. |
| To: | |
| Shared Package | |
| ML20079G498 | List:
|
| References | |
| FOIA-83-243, FOIA-83-A-18 BAW-1760, BAW-1760-R01, BAW-1760-R1, GPUN-TDR-007, GPUN-TDR-7, NUDOCS 8304250292 | |
| Download: ML20084G789 (199) | |
Text
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ATTACHMFNT Ori;inal Version Revision 1 Hone Page vit Pages 1-5 through 1-10 Pages 1-5 through 1-10 Figures 1-2 and.1-8 through 1-13 Figures 1-2 and 1-8 through 1-10 and 1-13 Tages 2-1, 2-3 through 2-5, Pages 2-3 through 2-5, 2-11 through 2-11 through 2-13, 2-15 through 2-18, 2-13, 2-18, 2-20, 2-22, 2-28, 2-29, 2-20, 2-27, 2-29, 2-34 through 2-39, 2-36 through 2-43, 2-49 through 2-5 2-41, 2-45, 2-47 through 2-49, 2-51, 2-54, 2-57, 2-58 through 2-61, 2-53, 2-54 2-63 thr6 ugh 2-69 Table 2-4 Tables 2-4 through 2-9 Figures 2-2 through 2-12, 2-14 through Figures 2-2, 2-3, 2-5 through 2-12, 2-17a, 2-19, 2-45, 2-46, 2-47B 2-14 through 2-17, 2-17b, 2-19, through 2-47f 2ac through 2-46, 2-49 Pages 3-1 and 3-2 Pages 3-1 and 3-2 Pages 4-2 and 4-3 Page 4-2 Page 5-3 Page 5-3 Page 6-2 None Dil.as.Been Sent to POR 1
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THREE-MILE ISLAND UNIT 1 l,
ONCE-THROUGH STEAM GENERATOR REPAIR Kinetic Expansion Technical Report r
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THREE-MILE ISLAND UNIT 1 ONCE-THROUGH STEAM GENERATOR REPAIR Kinetic Expansion Technical Report by J. P. Moore R. J. Baker L. D. Dixon J. R. Concklin J. A. Lauer Ap' s:
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DateY'S 3
- 0. G. Slear, GPUN, Manager, TMI En neering Pr et 29 Date.7/Mlff W. F. Pepreon, B&W, Matrager, TMI-1 OTSG Recovery Program Date D. H. Pai, FniEA, Executive Vice President BABC0CX & WILCOX Utility Power Generation Division P. O. Box 1260 Lynchburg, Vi rginia 24505 0
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SUMMARY
This report provides a comprehensive record of the technical bases for the ki-netic expansion process and related repairs, documents the results of analyti-cal and experimental work done in support of the program, describes the onsite installation of the repair and related controls, and presents the conclusions
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of GPUNC and their contractors Dabcock & Wilcox and Foster Wheeler Energy Ap-plications.
The report describes the OTSG kinetic expansion repair process, which includes flushing of the tube-to-tubesheet crevices on the secondary side of the steam
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generator, drying of the crevices to ensure that no water remains between the tube and tubesheet, and maintaining this condition throughout the process.
Also included are detailed descriptions of the kinetic expansion process and the subs'equent cleanup.
The repair method for the TMI-1 OTSGs involves expanding the existing tubes within the upper tubesheet at points below the location of the tube cracking.
The expansion closes the gap between the tubes and the tubesheet; it is accom-(,
p11shed kinetically using explosives (detonating cord) encased in a polyethyl-ene insert. The insert transmits the explosive energy to the tube wall and creates an interference pressure between the tube and tubesheet.
The tube expansion repair method is feasible because of the location of the cracking in the TMI-1 steam generator tubes. Most cracks are located in the upper ends of the tubes of the two generators, at or near the mechanically rolled and seal-welded portion of the 56-foot-long tubes. The combination of rolled joint and seal weld held the tubes tightly in place within the tube-sheets. The tubesbeets are 2 feet thick and contain holes for the 15,531 tubes in each steam generator.
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s Both 17-and 22-inch-long expansions will be used at TMI-1, depending on the axial location (within the upper tubesheet) of the lowest defect. The expan-sion length is chosen to provide the length necessary between the lowest de-
'fect and the bottom of the expansion to serve as the new pressure boundary.
For the TMI-1 OTSG geometry and materials, it has been shown that a 6-inch-long joint below the lowest defect provides adequate leak-tightness and load-carrying capability. All tubes that renain in service will be kinetically expanded, whether or not a defect has been detected.
Those tubes that cannot be repaired by this expansion process will be plugged, including those with defects below the upper tubesheet and those with defects in the lower portion of the upper tubesheet.
During the course of preliminary testing, it was discovered that the explosive expansion technique leaves a thin organic film on the tubes. Accordingly, a
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program for cleaning and/or protecting the tubes to maintain clean surfaces was undertaken. Preliminary tests resulted in identification of a material that is effective in providing a non-stick costing which can be cleaned off the surfaces after expansion. Procedures were developed to apply the material as a precoating for the kinetic expansion process.
This report contains a program description and data on all the tests needed to qualify the repair and meet GPUN specifications. This specification, in turn, is based on the conmitment made by GPUN to achieve essentially leaktight, load-carrying boundaries between the tubes and tubesheet in both steam genera-l tnrs and to maintain the structural design requirements of the original steam generator construction.
a Results clearly indicate that the load-carrying capability of the kinetically expanded joints is adequate to meet the load requirements based on the main steam line break, which is the most stringent load imposed on the steam genera-tors; leak rates are shown to be acceptable.
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CONTENTS Page 1.
INTRODUCTION...........................
1-1 1.1.
Purpose 1-1 1.2.
Scope 1-1 1.3.
Background.........................
1-1 i
1.4.
Kinetic Expansion Process 1-2 1.4.1.
Secondary Side Fl ush................
1-3 1.4.2.
Crevi ce Drying...................
1-4 i
1.4.3.
Immunol X-236 Precoat 1-5 L.
1.4.4.
Kinetic Expansion 1-6 1.4.5.
In-Process Inspection 1-9 r-1.4.6.
Cl e an i ng......................
1-10 1.4.7.
Long-Term Corrosion Testing 1-10 1.5.
Conclusions 1-11 c.
QUALIFICATION OF KINETIC EXPANSION PROCESS............
2-1 2.
2.1.
General 2-1 2.2.
Qualification Program 2-2 2.2.1.
Preliminary Tests 2-3 2.2.2.
Mt. Ve rnon Te sts..................
2-5 l
2.2.3.
Test Mockup Simulation of TMI-1 Steam Generators.....................
2-8 j
2.3.
Design....................
2-11 2.3.1.
Configuration 2-11 2.3.2.
Selection of Expansion Process Parameters 2-13 2.3.3.
Cyclic Loading...................
2-14 2.3.4.
Transition Stresses 2-14 2.3.5.
Effects of Kinetic E.rpansion............
2-16 2.4.
An al ys e s..........................
2-24 l
2.4.1.
Plant Parformance 2-24 2.4.2.
Load Conditions 2-25 2.4.3.
Joint Strength Calculations 2-28 l
2.4.4.
Marcin of Stability and Random Flow-Induced l
Vibration 2-33 l
2.5.
Joint Strength Testing...................
2-35 1
2.5.1.
Pullout Tests 2-35 2.5.2.
Tube Preload....................
2-42 2-43 2.6.
Joint Leakage Testing 2.6.1.
Design Objectives 2-43 2.6.2.
Mock-Up P ro c e s s i n g.................
2-44 l
2.6.3.
Leakage Test Results................
2-46 l
2.6.4.
Effect on OTSG...................
2-49 M
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CONTENTS (Cont'd)
Page 2.7.
Contamination.......................
2-52 2.7.1.
Control of Contaminants..............
2-52 2.7.2.
Moisture 2-55 2.7.3.
Residual Sul fur..................
2-56 1
2.7.4.
Polypropylene Film 2-57 2.8.
Co r ro s i o n.........................
2-58
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2.8.1.
Stress Corrosion Crack Resistance.........
2-58 2.8.2.
Boric Acid Attack.................
2-60 2.9.
Cleaning 2-61 2.9.1.
Debris Characterization..............
2-62 2.9.2.
Preliminary Tests.................
2-64 2.9.3.
Precoat EvaIuation 2-64 2.9.4.
Process Control of Final Flush 2-68 3.
POST-REPAIR INSPECTION AND TESTING 3-1 3.1.
Preservice Inspection...................
3-1 3.1.1.
Eddy-Current Inspection..............
3-2 3.1.2.
Profilometry 3-2 3.2.
Preservice Test Program..................
3-2 3.2.1.
Lo ad i n g o n OTS G Tu be s...............
3-3 3.2.2.
Test Methods 3-3 3.2.3.
Backup Repair Method 3-3 3.3.
Hot Precritical Testing..................
3-4 4.
PERSONNEL SAFETY 4-1 4.1.
Ventilation........................
4-1 4.2.
Noise...........................
4-1 4.3.
Explosives Handling....................
4-2
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5.
QUALITY ASSURANCE........................
5-1 5.1.
Quali fication Program...................
5-1 5.2.
Manufacturing.......................
5-2 i
5.3.
In-Process General Requirements..............
5-2 5.3.1.
Verification of Pre-Process Requirements 5-2 l
5.3.2.
In-Process Requirements..............
5-3 6.
RADIOLOGICAL SAFETY.......................
6-1 l
6.1.
ALARA Evaluation of Implementation Process 6-1 l
6.1.1.
Expansion Device Installation Technique......
6-1 l
6.1.2.
Tube Precoating Techniques 6-2 l
6.1.3.
Airborne Contamination Potential 6-2 6.1.4.
Temporary Shielding................
6-3 l
6.2.
Training 6-3 6.3.
Open Items 6-4 6.4.
S uma ry..........................
6-4 l
REFERENCES A-1 l
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Shaped Inserts tJsed for Expansion' Transition Stddies...'..
2-88 2-11.
2-12. Measured Transition Slopes..... '...~..........
2-89 2-12a. Residual Stress Measurements for High Y* eld Tube (Penn State)................" S.'.......
2-90 2-12b. Residual Stress Measurements for Low yield Tube -~
2-91 (Penn State).
5.,...... s..............,
2-13.
OTSG Full-Scale Test, $drostatic Tesi Pit-at Mt. Vernon...........
5. '.s.
2-92 2-14.
Data Sample,,Mt Vernon Profilometry. Data.,..........
2-93 s.......
2-94 2-15.
Concept of Tube Load Test ?... '. $.
2-16. Logic Chart, Leak and Axial Lodd Teits. <,.'........
2-95 2-17.
Pullout Load Qualification,and;Prequalificacion Data..
g...
2-96 y
2-17a. Qualificatic'n Program Leak flate Dats, Ten-Tute i
Test Blocks..........'.............:
2-97 2-17b. Effect of Crevice Corrosion.........'........
2-98 2-18.
Tube load Vs Joint Strength During LOCA
......., y 2-99 2-19.
Ten-Tube Leak and Load Test Fixture
~2-100 J
2-20.
Temperature / Pressure Vs Tiine Leak Data, 0-52 Hours.... ~...
2-101 2-21.
Temperature / Pressure Vs Time' Leak Data. 0-60 Hours..'.>.
2
'2-102 2-22.
Straight Tube Model With Elastic Radial Displacement..
2-103 2-23.
Straight Tube With Short Transition and Free End (Case N1),,, '
Tube Stress Distribution - Inside. Surface
~.....
2-104
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2-24.
Straight Tube With Short Trans.ition and Free End (tase _N1),
Tube Stress Distribution - Outside Surface...... '....
2-105
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2-25.
Expanded Scale Straight Tube With Short Transition and Free End (Cas'e N1), Tube Stress Distribution - Inside 2-106 Surface l
2-25.
Expanded Scale Straight Tub ~e With Short Transition and Free End (Case N1), TU'ie Stress Distribution - Outside Surface..:.....s..........."..........
2-107 l
2-27.
Straight Tube With;Long Transition.and Free End (Case N2);
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Tube Stress Distributforc-Inside Surfacs... <.......
2-108 2-28.
Str2ight Tube With Long.Tran-ition and Free End.(Cass N2),
Tube Stress Distribution - Outside Surface..........
2-10 9 2-29.
Straight Tube With Short Transition.cnd End Rollers (Case 0), Tube StresrDistributicin - Iside surtace 2-110 2-30.
Straight Tube With Short Transitioic and End Rollers (Case 0), Tube StresV0istrib'utios-Outside Secface.....
2-111 2-31.
Expanded Scale' Straight Tube:With Short Tradsition and End Rollers (Case 0),-Tube. Stress Distribution - Inside 2-112
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Surface...........................
2-32.
Expanded Scale Straight Tube With Short, Transition and Outside End Rollers (Case 0), Tube Stress Distrioution 2-113 Surface...........................
2-33.
Straight Tube With Long Transition.,and End Rollers (Case P), Tube Stress Distribution -- Inside Surface 2-114 2-34.
Straight Tube With Long Transition and End Rollers (Case P), Tube Stress Distribution ~ Outside Surface.....
7-115 2-35. ' Straight Heavy Wall' Tube With Long Transition and Free "
End (Case Q), Tube Stress Distribution - Inside Surface 2-116
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List of Figures (Cont'd)
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Figure Page
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2-36.
Straight Heavy Wall Tube With Long Transition and Free End (Case Q), Tube Stress Distribution - Outside aurface...
2-117 2-37.
Plastically Deformed Tube Model With Interfacial Pressure Load and Free End 2-118 2-38.
Plastically Deformed Tube Model With Interfacial Pressure Load and End Rollers.....................
2-119 2-39.
Deformed Tube With Short Transition and Free End (Case R),
Stress Distribution - Inside Tube Surface 2-120 2-40.
Deformed Tube With Short Transition and Free End (Case R)
Stress Distribution - Outside Tube Surface..........
2-121 2-41.
Deformed Tube With Long Transition and Free End (Case S),
Stress Distribution - Inside Tube Surface 2-122 2-42.
Defomed Tube With Long Transition and Free End (Case S),
Stress Distribution - Outside Tube Surface...
2-123 2-43.
Deformed Tube With Short Transition and End Rollers (Cise U), St: ess Distribution - Inside Tube Surface 2-124
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2-44.
Deformed Tube With Short Transition and End Rollers (Case U), Stress Distribution - Outside Tube Surface.....
2-125 2-44a. Strain Gage No. 3, Exploded and Top Views 2-126 2-44b. Strain Gage Mc. 5, Exploded and Top Views 2-127 2-44c. Distribution of Residue in Tubes, Typical 2-128 2-45.
Stereo Pair, Tube A133-74, Piece 2. Upper Crack 2-129 2-130 2-46.
Stereo Pair, Tube A133-74, Piece 2, Lower Crack ~
2-46a. Specimen' Layout and Discolored Area - ID ' Surface of Tube Sample ARC-30 2-131
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2-46b. Cracking in Strip 1A of Tube Sample ARC-30..........
2-131 l
2-46c. SEM Photograph of Large Crack in Strip 1A of Tube Sample ARC-30 (32X) 2-132 l
2-46d. Tip of Large Crack in Strip 1A of Tube Sample ARC-30 (4 60X ).........................
2-132 t
1 2-46e. Crack Tip Area in Strip 1A of Tube Sample ARC-30 (140CX) 2-133 2-46f.
100". Through-Wall Circumferential Crack After Coating, Sample B-1 From Tube A78-32.............
2-134 2-47.
Obrigheim Steam Generator Tube, As-Built...........
2-135 2-47a. Comparison of Rockwell Hardness 2-136 2-47b. Unexpanded Portion of Tubes 100X 0xalic Etch.........
2-137 2-47c. Roller Expanded Tube Away From Transition Area 100X 0xalic Eten.......................
2-138 2-47d. Kinetically Expanded Tube Away From Transition Area 100X 0xalic Etch 2-138 2-47e. Roller Expanded Tube Transition Zone (100X 0xal i c Etch)......................
2-139 2-47f. Kinetically Expanded Tube Transition Zone (100X 0xalic Etch)......................
2-139 Z-48.
Multi-Tube Block Specimen 2-140 l
2-49.
Adjacent Tube Mockup.....................
2-141 3-1.
OTSG Bubble Test.......................
3-5
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1.
INTRODUCTION 1.1.
Purpose A kinetic expansion technique has been developed for the repair of tube leaks that have been found in the once-through steam generators (OTSGs) at Three Mile Island Unit 1 (TMI-1). This technical report describes all the tests, analyses, and examinations that have been performed in order to show the adequacy of the TMI-1 OTSG kinetic expansion repair program.
1.2.
Scope This is.a comprehensive report which sununarizes the objectives and results of each test and analysis undertaken to verify the' adequacy of the kinetic expan-sion process. The c;mulative results of this work lead to a conclusion that the kinetic expansion technique is a safe and reliable method of repair for the tubes in the TMI-1 OTSGs.
Section 2 describes the qualification of the kinetic expansion process.
In-l spection and testing of the steam generators are discursed in section 3.
The objectives, methods, results, and conclusions are summarized for each piece of work, and appropriate references are listed for further details. The report concludes with discussions of personnel safety, quality assurance, and radio-logical safety in sections 4, 5, and 6, respectively.
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1.3.
Backaround In November 1981, after a 30-month cold shutdown period followed by hot func-tional testing and two more months of cold shutdown, the TMI-1 rear. tor coolant system was pressurized to about 40 psig, and many small leaks were detected in the OTSG tubes. Subsequent investigation revealed that a large number of l
tubes in each of the two OTSGs had through-wall circumferential cracks within 6 inches of the top of the 24-inch-thick upper tubesheet. Some of the tubes have similar cracks below this level. Figures 1-1 and 1-2 show the design and technical data for the OTSGs.
1-1
._ -7__.___
Failure analysis has resulted in the conclusion that the OTSG tubes were at-tacked by intergranular stress assisted cracking, where the aggressive environ-ment was provided by various sulfur species following hot functional tests.
The attack is inside-diameter-initiated and generally circumferentially oriented except for the tap 1/4 inch of tube which has some axial defects.
j The majority of the cracking has been located by eddy-current testing (ECT) in the upper end of the Inconel 600 tubes at or near the weld heat-affected zone (HAZ) and the roll transition in the upper 6 inches of the tubesheet region (Figure 1-3).
The details of the failure analysis are given in reference 14.
Since the results of the failure analysis indicate that the areas of tubes free of ECT indications can be successfully returned to service, a repair pro-
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cess was selected that kinetically (i.e., explosively) expands the existing tube against the upper tubesheet hole. The objective was to expand the OTSG tube for a sufficient length below any defects to form a new load-carrying and essentially leaktight joint. Tubes with defects in the upper 16 inches of tne upper tubesheet were explosively expanded to seal off the defects. Tubes with defects below that level will be plugged.
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All tubes that will remain in service in both OTSGs have.been kinetically ex-panded within the upper tubesheet by~ the repair process regardless of whether or not they are cracked. Approximately 31,000 tubes were expanded. The ini-tial design life of the tube repair is five years, and additional tests will
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be performed later to qualify the repair process for a 35-year life.
- 1. 4 Kinetic Expansion Process The kinetic expansion technique has been used for repairs by the major NSS and boiler manufacturers. Foster Wheeler has expanded more than 5 million tubes in heat exchangers over the past 20 years, including 17,100 expansions in the Clinch River Breeder reactor' intermediate heat exchanger and 17,640 expansions in repairing moisture separator reheaters at Salem I and 2.
Westinghouse and Combustion Engineering have used the process to close tube /tubesheet crevices in steam generators, and Babcock & Wilcox has tested it as a manufacturing pro-cess and placed three tubes in service at Oconee 3 with 24-inch expansions at both ends.
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At TMI-1, the process consists of flushing the secondary side to remove contam-inants from the crevices, drying the crevices to remove water, and the kinetic expansion itself.
r-1.4.1.
Secondary Side Flush Prior to actual OTSG tube repairs at TMI-1, a secondary side flush was per-fomed to wash chemical contaminants (sulfur) out of the tube /tubesheet crev-ices. To this end, a procedure was followed to force the OTSG shell side fill water into the tubesheet crevices.
The objective of the secondary side flush was to minimize the residual corro-sive contaminants in the tube-to-tubesheet crevice. The following steps were accomplished on both TMI-1 OTSGs:
r-1.
Baseline chemistry data were obtained by analyzing secondary side water L
samples for cation conductivity and chemical and radiochemical parameters (see Table 1-1).
l 2.
The OTSG secondary side was filled with demineralized water and pressur-ized by applying a 100 psig nitrogen overpressure to the main steam lines.
This condition was maintained for at least one hour while recirculating the OTSG secondary side water to flush the system (Figure 1-4).
i' 3.
Secondary side water samples were taken and analyzed; results are listed in Table 1-2.
4.
The OTSG secondary sidc water level was lowered to the steam cutlet noz-zies (about 420 inches) while backfilling with nitrogen (reference Figure 1-5).
I 5.
A vacuum of about 29 inches Hg was drawn on the secondary side using tem-porary vacuum pumps. This evacuation was to draw the water and any con-taminants it may have dissolved out of the crevice.
The pressure range from 29 inches Hg vacuum to 100 psig ensured that the cre-vice was at least 99". filled with flush water. The procedure called for re-peating this process until the sample was within layup water quality limits, and there was no significant change in chemistry from the previous sample. The first flush caused little or no change in contaminant levels in the bulk water. However, the flush was perfomed three times on each steam generator to provide additional assurance that the crevices were adequately flushed.
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1.4.2.
Crevice Drying The crevice between the outer tube wall and the tubesheet may contain water,
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and any water in this area of the joint should be removed before kinetic expan-sion. Because of its incompressibility, water could impair formation of the new expanded joint if present in the area of the expansion.
Initial dryness was established by heating the tubesheet to temperatures above the saturation temperature of the water in the crevices. Dryness was maf r.tained by keeping the dew point of the secondary side cover gas below the tubesheet temperature.
The tubesheet heating procedure has been tested successfully at B&W's Mt.
Vernon plant (see 2.2.2.1).
Evacuation The secondary side water level was lowered to a point below the steam outlet nozzle while backfilling with nitrogen.
Initially, water was removed from the crevice by drawing a 26-to 28-in. Hg vacuum on the secondary side. This evac-l uation allowed the gasss in the tube /tubesheet crevices to expand and expel water from the crevices. The remaining water was removed by evaporation dur-ing subsequent heating, i
Thermocouples were installed on the top of the upper tubesheet'in a predeter-mined pattern to monitor tubesheet temperature during dryout. Four sets of temperature probes were also installed in the steam generator tubesheet -
l three equally spaced around the perimeter and one in the center. Each set pro-vided three tenperature readings: at the bottom, center, and top of the upper tubesheet. Resistance heaters were placed on top of the tubesheet as shown in Figure 1-6 and covered by a blanket of insulation.
Heating With the vacuum still on the secondary side of the OTSG, the heaters were turned on to raise and maintain the temperature at the bottom of the upper tubesheet at least 10F above the saturation temperature of the secondary side, while holding the temperature at the top surface below a maximum of 350F.
Heating continued until all the temperature probes and thermocouples indicated that the crevice was dry (temperature above saturation). The heaters were then turned off, and the vacuum broken by backfilling with nitrogen.
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Steam generator repair qualification corrosion testing will consist of two separate programs. One, described as the lead test, will take actual TMI tube st.mples and subject them to thermal and mechanical loading typical of that experienced by the steam generator tubes during hot functional testing and subsequent operation. The specimens to be tested will contain known defects as well as specimens that are defect-free and specimens that have been sub-jected to any sulfur cleaning operations utilized in the generator. This test will use environments representing the worst-case conditions allowed by reac-tor coolant system chemistry specifications. In addition, various boron con-centrations, representative of those experienced during core life, will be maintained during the tests.
The repair test will use similar operational cycles; however, specimens will be fabricated from actual TMI tubes which have been explosively expanded i'nto single tube /tubesheet mockups. These mockups will assess the effect of the new expansion transition on material susceptibility to integranular stress-corrosion cracking (IGSCC). Specimens will be tested in both the as-expanded condition and expanded with applied load. These tests will be initiated p.-ior to the restart of TMI-1 and will lead operation by at least one month.
1.5.
Conclusions The following conclusions have been drawn from the tests and analyses:
1.
Based on a qualification program, the kinetic joint meets or exceeds the design bases of the original joint, including the following factors:
a.
Load-carrying capability.
b.
Tube preload.
l l
2.
The effects of the repair are not adverse when evaluated with regard to the following:
a.
Leakage.
b.
Introduction of chemical residue.
l c.
Reactivation of cracking due to drying.
d.
Effect on OTSG structure.
e.
Effect on previously expanded tubes.
f.
Effect on previously plugged tubes.
l g.
Creation of residual stresses.
1-11
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3.
Personnel safety during the repair has been satisfactory with respect to ventilation, noise, and explosion hazard.
4 Xinetic expansion in the upper tubesheet is a safe and reliable method of repair for all tubes that will remain in service in the TMI-1 steam genera-tors. The tube joints will remain structurally sound and essentially leak-tight during all design conditions. The likelihood of ccerosion damage is no greater after the tubes are kinetically expanded. The expansion pro-cess creates no significant risk of structural damage to the OTSG or of personnel injriry.
5.
The procedures and methods used to implement the repair have been evalu-ated by analysis and by tests in a full-size steam generator mockup to ensure that radiation exposure of personnel is as low as reasonably achieveable (ALARA).
m n
1-12
.- =.
--+
- =
- =
.~
-. =.
e, g
2__
Table 1-1.
Secondary Systen Water Samples Before Starting Crevice Flush Procedure OTSG A OTSG B pH 10.10 10.20 Cation conductivity, umho/cm2 2.23 2.29 Chloride, pp:n 0.058
<0.050 Sodium, ppm 0.070 0.076 hnmonia, ppm 28.2 48.3 Hydrazine, ppm 70 72 Cesium-134,uCi/ml 7.5 x 10-7 1.0 x 10-6 Cesium-137, uCi/ml 2.6 x 10-6 3.8 x 10-6
~
Tritium,uCi/ml 1.1 x 10-5 1,1 x 10-5 t
t e
i r
1-13 m
L l
.t i
I l
Table 1-2.
Secondary System Water Samples During Crevice Flush Procedure OT5G A DISG I
2 3
4 5
6 7
8' Date 7/29 7/31 8/2 8/.3 1/21 7/21 7/23 7/25 j
Time 2145 2205 2215 0325 0135 2100 0530 1750 pii 9.58 9.92 9.72 9.72 9.%
9.74 9.90 9.S3 Catton conductfwity, id o/ca' O.88 1.03 0.86 0.97 0.95 1.25 1.28 1.12 l
Conductivity, 21.5 30.4 i.sho/ca*
11.1 21 14 16 2 5. 11 Chlorlde, ppe
<0.05 (0.05
<0.05
<0.05 (0. 0%
0.08
<0.05
<0.05 Hydrazine, ppe 0.16 0.01 0.11 0.18 0.64 0.37 0.35 0.73 Amment a, ppm 2.4 1.4 4.2 4.9 13 12.3 8.0 12.4 Sodlum, ppe (0.015 0.020
<0.01
<0.01
<0.015 0.03 0.015 0.015 0.019 0.027 0.020 0.023 Silica, pre 0.018 (0.01 f
<MDA OWA '
Ceslum-134,sitt/mi 1.3 x 10" 1.4 x 10 '
l.5 x 10d 1.6 x 10" 9.4 x 10 "
Z Ceslum-137, pct /ml
<8.0 x 10-6 9.7 x 10-*
1.5 x 10-5 0.3 x 10 -
<8.1 x 10-6 Trittua, pct /mi Notes:
1.
Af ter initial drain and refill of OTSG A to dilute hydrazine - sample somdiat non-representative in that ammonia concentration did not Indicate the amount added until later samples wre taken.
2.
Af ter first pressurization, drain down to 420 in. establish vacuum and refill sequence on A UT5G.
f 3.
Af ter second sequence as noted in 2 above.
4.
Af ter third sequence as noted in 2 abcve.
5.
Af ter initial drain and refill of OTSG B to dilute hydrazine.
6.
Af ter first pressurization of OISG 8.
7.
Af ter second p:essurization of OTSG b.
8.
Af ter third pressurization of OTSG B - ammonta added.
{
t I
5 I
f u
j g
l t
l Figure 1-1.
TMI-1 Steam Generator, Schematic and Specifications l
ELEVAT10N CROSS SECTION PRIMARY SIDE n
.- w
- p. ~.' t.b..
(INSIDE TUBES)
J L
- 7 UPPER g.-.--j _
TUBESHEET (UTS)
FEED T
~5"
. i* -
I
- "' 5
-gitneyeesang N0ZZLES X
(AFW)
, gj.,
f 4. g Ee.,q_g,.g g
j
-m-a.w wO.s.
f lLt !A
,1.c1.M46 g"
--m i
- im -
T
,y.
, *
- 9j,_.* -. - -
-~:
r
_ 8? - -
STEAM OUTLET
-'m-
.-w '-
m.
_,m. - -
n.
l l h.'*, -
LANE MAIN FEEDWATER I ka#
CTUBE N0ZZLIS (MFW) y
- =
i
- e u...
m e O
(,g D
SECONDARY SIDE EXTERNAL TO TUBES)*d(,;d,'
-- m.
Vl'1 lh '
Weight. operating.............. 637 tons H eight....................... 7 3 f eet i
p Primary flow.................. 6 SX106 #/hr.
Steam flow.................. 6.1X106 #/hr.
SUP PLATES \\
as -
- t' Number tubes................. 15 531 h-
' g.
Tube size. material............. 0.625" od. 034 wall 3
i inconel 600 LOWER W Manufactura date.............. 5/69 to 11/70 n
SECDNDARY HAN0 HOLD i
1 1-15
l Figure 1-3.
TMI-1 Steam Generator. Typical Cracks INCONEL TUBE g
JN pj N
^
p q
TYPICAL CRACKS ROLL TRANSITION
/l V
V 9
a/STEELTUBE 96 9
as
//
l CRACK CHARACTERISTICS: CIRCUMFERENTIAL BELOW FILET WELD NOT FULL AP.C GENERALLY VERY TIGHT PRIM ARY SIDE INITIATED 1-17 e
'-*e-
-e.-
o w
w-w
--w
Figure 1-4.
Tubesheet Crevice Flush / Dry Program - Vacuum / Nitrogen / Level Indicator Flow Diagram e
Vihl
~
m3 suett g'
J.
.i li....
i
' '- W
.in...a...s.
i., ie_ _ 'nJ:'
w..
_m 1x1 2
10Cflew us.Vil 55 5) 3gg.
l
~b 0
,N2 SUPPt f 344**l. 1/4"
.... u...
Y
=
st tp
,,,4 X I
j st, 333. p=
is vees 3
- 1 1/3'Vtul
}---
323*.4*
g gg, gig.
I a
i I
b ff VSI m
it 150 le littl LI.t Et, 383 *.3*
10 LEVEL LI 1-EL.193* 3*
i
__ M f t-t 75 l'
l' ff*? 79 x*<
in-e es l lllElll l
l
'D<&
-D<P 1
r aa T_x_]
m i
1 j
i t
I i
i
)
I
'i
I I
i l
Figure 1-5.
THI-1 OTSG Tubesheet Crevice Flush / Dry Program, Na Supply Flow Diagrace j
i
\\
FRON N2 EXISTING TEMPORARI
-SYSTEN VENT
\\
\\ \\
TO DISS TO OTSG VENT I
k I '
m-ES-V84 (A,8)
.yi.V32 i
EXISTING TEMPORARY 4
VACUUN Y
RE LATOR PutiP G
SUCTION X
X x
l X""*'"
I l 6
l Figure 1-6.
Crevice Orying 1
HEATERS ARE INSTALLED ON STAINLESS STEEL SPACERS CN TUBESHIET AND ENTIRE POWER LEADS TOP SURFACE OF HEATERS IS COVERED WITH INSULATION T
- THERM 0CDUPLES l
..)
l I
I I
I I
I I
PRIMARY +
MANIAY I
II 1 1 IL I
I I
D@
I UPPER SURFACE { 300*F 8 LCWER SURFACE 210' ABOVE TSAT I TIME REQUIRED = 4 HOURS I PERFORMANCE CONFIRMED BY MT. VERNON TEST l
t i
l 1-20
Figure 1-7.
Forced Circulation System for Keeping Crevice Dry 100 CFM CESIGN CEHUMIDIFIER TEW./HlNIDITY INDICATOR N2 MAKEUP f
I I
HANC AFW N0Z2LE
-(/ HOLE 1
/
e T
N2. COVER GAS
~-T HO NOTES:
2 3
LPPER TUBESHEET TEMP.
MEASUREMENT AT 4 TUBE LOCATIONS l
l e
CEW POINT ON SECONDARY SIDE MAINTAINED 10 F BELOW TUBESHEET TEW ERATURE 1-21
figure 1-11.
Repair Configuration of OTSG Tube A
4 4
a
/
" 8 Original Shop gt c
Defects 3
Roll 1" min.
sil" Kinetic
\\
Expar.sion s17" u
.L y
Essentially Leak-Tight Load Carrying Region of Expansion: 6" y
y r-Tubesheet 24" Existing Crevice 0.002 to 0.008 (Radial)
/\\ \\
U l
Note:
Tubes with defects between 11 and 16 inches below top face of upper tubesheet will be expanded to 22-inch length.
l l
l l
46 1-25 l
Figure 1-12.
Kinetic Expansion Length i
PRIMARY FACE UTS W/////fBiWA T' 7
'*:yl-Q
~?
ZONE WITH LENGTH OF C
DEFECTS
- EXPANSION A
I*
I; A
17 s.
..r B
22 g;
?;;;..
- :i ijj_.-',...
.~
q-r...,
(
e
.:. y-i 33 i;6 B
=
33
!=t ki
- TUBES WITH MULTIPLE DEFECTS IN 16" "T
T~
THESE ZONE COMBINATIONS TO RECEIVE 1T. ~.~.
22" EXPANSIONS S!!
~
ar.
22"_ _ _ _ _ _
W//////fB VA SECONDARY FACE UTS
.s 4 1-26
._--1----______.
___s-..
%..-n.~~_-w..-
_ ~ ~ *
._ u -_
1, Figure 1-14.
OTSG Flush System I
EQUIPMENT a INTERFACE d
2" NPS HOSE COUPLING EXHAUST OTSG y
A RECIRC TO LOWER HEAD m2 r,
)
?;c Fil.L WATER h
~~
e - CHEMICALS FLOW 3
W X
a g
P C
CD Q
-w h
150 GPM P = PRESSURE GAUGE l
200 FT HEAD F = STRAINER / FILTER S
CENTRIFUGAL PUMP S = SAMPLE POINT FM-1 = FLOW METER 400 GPM i
1-28 l
L
r d
2.
QUALIFICATION OF KINETIC EXPANSION PROCESS
- d 2.1.
General The tube and tubesheet form a portion of the primary nystem pressure boundary.
The original joint consisted of a shop roll expansion and a tube-to-tubesheet wel d.
The shop roll was intended to hold the tube in tension until it could be welded. The weld was the primary pressure boundary and structural attach-ment although the roll expansion shared some of the load. The joint was de-signed for maximum primary and secondary pressures of 2500 and 1050 psi, re-spectively. The design temperature was 650F for the primary side and 600F for the secondary side.
The new joint comprises a kinetic expansion of approximately 17 inches, which 4
begins just below the upper tubesheet top surface in the area of the original shop roll expansion. The kinetic expansion extends at least 6 inches into l
tubing indicated (by eddy-current test using a 0.540-inch standard differen-tial probe) to be free of defects prior to expansion. The expansion forms the pressure boundary and structural attachment of the tube to the tubesheet. All qualification tests for length-dependent properties (i.e., letkage and load-ing) were performed for a 6-inch expansion length although a much longer ex-L, pansica will be functional for most or all tubes. Similarly, the original tube-to-tubesheet weld was ignored as a source of sealing and structural at-tachdant. A design objective was to produce a repair configuration that will h
accennodate future sleeve installation.
The repaired OTSG satisfies all applicable design parameters originally used 3
for the TMI-1 OTSG. These include the ASME Code,Section III with Addenda I
through Summer 196743 and the original B&W specification.44 As a repair, it is governed by Code Section XI with Addenda through Winter 1975 or later, which permits later revisions of Code Section III. The repaired tube is a Seismic Category 1 component in accordance with Regulatory Guide 1.29 and a Class I component in accordance with Regulatory Guide 1.26.
The effects of 2-1 e-w-*-+her.wweaw.-w 9.e.gde---
--ee--e+
.A e
.w ww -
+
- +--
g-
4
_ _.7
~
both repaired and plugged tubes on the thermal and hydraulic performance of the plant and on the structural and vibrational adequacy of the steam gene-rator are within the acceptance criteria for both normal operating and design
.. basis accident conditions.
The loading conditions considered include operating pressure, thermal stress-es, flow-induced vibration, seismic accelerations and displacements, and faulted conditions such as loss of coolant (LOCA) and main steam line break (MSLB).
f.2.
Qualification Program The overall intent of the qualification program was to perform sufficient anal-yses and statistically based tests to result in a high degree of confidence that the kinetic expansion process complies with the following criteria:
Capable of providing an essentially leaktight joint.
Capable of carrying the design basis loads.
Maintain the tensile preload in the freestanding portion of the tubes within allowable limits.
Result in minimal transition stresses.
Expansion that can be, examined by nondestructive means.
The qualification program consisted of analytical and test programs. The test program was divided into (1) preliminary testing to establish optimun param-eters for the procets. (2) mechanical tests to qualify the new joint, and (3) accelerated corrosion tests. Figure 2-2 shows details of the test pro-grams. Key elements of the qualification program are summarized below.
I. Joint Qualification Prototypical kinetic expansions Proof test expanded joints Thermal cycle-condition joints l
Axial load-condition a set of joints Determine water leak rates Determine joint pullout strength II. Supporting Tests Evaluate residual stress at joint transition Determine adjacent shot effects 2-2
1._____
The tests provided full-dress mockup training and testing of installa-tion tools and procedures.
The reliability of the support systems was verified.
4 The expansion process was refined, saving more than an estimated 200 man-rem exposure to personnel.
The magnitude of post-expansion cleanup was assessed.
Profilometry data were obtained.
An expansion pull test was performed.
The kinetic expansion process tests were performed in a partially assembled OTSG at Mt.'Vernon. The assembly of the Mt. Vernon OTSG is essentially com-plete, except that the upper and lower head are not permanently attached.
~
This OTSG was built for use in a B&W 205-FA plant. The similarities and differences between the 205-and the 177-FA OTSGs at TMI-1 are summarized bel ow.
Similarities Description Value J
'1.
Hemispherical head, radius at tangent line, in.
59-17/32 2.
Tube material Ni-Cr-Fe SB-163 3.
Tube 00, in.
0.625+g.00g 1
4 Minimum tube wall thickness, in.
0.034 5.
Minimum tube expansion from primary face of 1
upper and lower tubesheets, in.
6.
Spacing of holes center-to-center, in.
0.875 t0.010 7.
Spacing of rows center-to-center, in.
0.7578 8.
Tubes installed in tubesheet Not in compression at ambient temp 9.
Upper and lower head material Mn-Mo, SA-533 j
Gr B, Cl 1 j
- 10. Upper and lower tubesheet material Mn-Mc, A-508 C1 2 2-6 i-a_
Differences Description 177-FA OTSG 205-FA OTSG 1.
Minimum thickness of hemisphereical 8
6.0625
. head, in. +
2.
Shell materf al Carbon steel Mn-Mo, SA-533 S A-212-B Gr 8 Cl 1 3.
Shell length, f t-in.
51-8.375 51-2.875 4.
Tubesheet thickness, in.
24+]/16 21-5/8+]/16 5.
Diameter of holes in tubesheet, 0.635+@,@@{
0.640+@-@@{
in.
6.
Tube extension above tubesheet, 0.187%,8@{
0.010$,8{8 in.
7.
Type of tube /tubesheet weld Fillet Flush 8.
Nu2er of tubes 15,531 16,016 Number of rows of tubes 151 155 9.
- 10. Max numer of tubes in row 132 134
- 11. Tube yield strength ( range),
40,000-64,900.
35,000-57,500 psi
- 12. Nu2er of tubes eliminated' for 62 None inspection lane
- 13. Nuter of tubes removed from 32 7
center
- 14. Nuter of support plates 15 17
- 15. Number of support rods 42 50
- 16. Post-weld heat treatment, hours l
"A" OTSG 247 None perfonned Total avg above 1100F 13 "B" OTSG 204 l
Total avg above 1100F 13
- 17. Years of operation (approx.)
5 None In addition to the kinetic expansion process, the Mt. Vernon testing proved techniques for crevice drying (section 2.7.2), precoat application and removal (section 2.9.3), and tube pull testing (section 2.5.1.11). The dif ferences be-tween the 177-and 205-FA OTSGs are considered to be insignificant for this testing.
l 2-7 l
1 7.--
=_
2.2.3.
Test Mockup Simulation of TMI-1 Steam Generators For the manufacture of mockups to be used in qualification testing (Figure 2-19) three sets of parameters uere intended to duplicate or bracket actual steam generator conditions. The parameters are material properties, surface condition, and geometry.
2.2.3.1.
Material Procerties TMI-1 tubesheets are SA 508 C12, nuclear grade forgings with 0.2% offset yield values from 65.5 to 73.0 ksi according to the supplier's (Bethlehem Steel) material test reports. The material used for the tubesheet portion of the mockups (which are being used for the various qualification tests) is all SA 508 C12, nuclear grade forging with 0.2% offset yield values rancing from 64.7 to 70.0 ksi.
All yield strength values listed above are prior to stress-relief heat treat-ment. Tubesheet material for all qualification testing has been heat-treated in a manner to simulate stress-relief time at the temperatures seen by the TMI-1 steam generators during fabrication.
TMI-I tube's are SB-163' Inconel 600. ' Tubes that are positively tra'ceable as being in the TMI-1 steam generators have 0.2% offset yield strength values from 41.0 to 61.1 ksi. Tubes that may be in the generators, but which are not individually traceable as such, have 0.2% offset yield strength values from 41.0 to 64.9 ksi.
Tests on tubing taken from TMI-1 steam generators in areas that are not cracked have indicated that the mechanical properties of the metal are unaf-fected by the contaminant. Measurement of yield and ultimate loads indicate that strength and ductility are comparable with those of other tubes with simi-l lar operating histories and either may be used for qualification purposes. Be-cause of schedule considerations, available in-stock tubing was used in the mockups. Tubing used for the mockups is SB-163, Inconel 600 steam generator tubing with 0.2% offset yield strengths of 41.5 to 54.7 ksi.
All yield strength values used above are prior to stress-relief heat treat-ment. Tubing for mockups for qualification testing has been heat-treated in a manner to simulate stress-relief time at the temperatures seen by the TMI-1 steam generators during fabrication.
2-8 e
,v.De--..-m.-..v r---n
,.e=-
Preliainary tests have shown that the use of low yield strength tubing results in the lowest pullout loads. Therefore, low yield strength tubing (41.5 ksi) is used for most pullout load test mockups with high yield strength (54.7 ksi) tubing used in some locations for comparison.
2.2.3.2.
Surface Condition The holes in the TMI-1 tubesheets were gun-drilled. All tubesheet mockups for qualification testing were also gun-drilled. In cases where the geometry of the test mockup (see section 2.2.3.3) was felt to be more important than pre-
~
cise duplication of surface finish, the holes were honed to obtain exact di-mensions. The honing operation produces approximately an 80 RHR surface finish as compared to a finish of approximately 125 RHR produced by gun drill-i ng. Ten-hole mockups used in the measurement of leak-limiting and tube load-carrying capabilities have been gun-drilled only.
All mockups used for tube pullout and leak testing have been corrosion-condi-tioned to simulate the TMi-1 tube and tubesheet oxide layer chemistry and thickness.54 The oxide thickness on the upper tubesheet in the crevice region was not and could not be measured without cutting a section of material out of the tube-sheet. Thus, it was necessary to estimata this oxide for TMI-1 and to estab-lish conditions that would produce a similar thickness of oxide in the mockup assembly.
These estimates were obtained by calculations based on laboratory oxidation data. The thickness of oxide on the TMI-1 tubesheet was extrapolated from Central Electricity Generating Board data for the oxidation of mild steel in steam at about 850-1500F. The air exposure time and temperature required to produce an equivalent oxide layer were estimated from B&W air oxidation data at 900 and 1000F. From these two sets of data it was decided that exposure in air at approximately 1000F for 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> would produce an adequate simulation of the oxide in the TMI-1 OTSGs tubesheet crevices.
In addition tests were conducted with less and more oxide to demonstrate the sensitivity of load-carrying capability and leak-tightness to varying amounts of corrosion (section 2.6.3.1).
l 2-9 m
m m-w--r--
,, ?
~
'f_
7_-_______
The oxide on the steel tubeshee' in the upper portion of the upper tubesheet crevice in TMI-1 is expected to be mostly magnetite, with a very thin surface layer of hematite. This is the type of oxide produced by the action of steam on iron and mild steel over a broad range of temperatutes, pressure, and oxy-gen activities. Very similar oxide layers are produced by the oxidation of iron and steel in air.
Video tapes of the TMI-1 tubesheet hole ids were viewed by B&W personnel, and the surface appearance was judged to be typical of that expected due to expo-sure in a steam environment. There were no indications of aonormal oxidation.
In addition, the surfaces of tubes pulled from TMI-1 steam generators are very similar - with respect to oxidation - to those of tubes examined in the labora-tory from other commercial power plants and model boilers.
It is believed that these facti permit the conclusion that the surface oxide produced on the tube /tubesheet mockups for the TNI-1 qualification program is representative of that found in the TMI-1 steam generators.
2.2.3.3.
Geometry Tubing for use in the mockups was obtained from stock sources; therefore, its OD and wall thickness were not controllable dimensions. The maximum and mini-mum possible tube-to-tubesheet gaps by an accumulation of drawing tolerances are 0.016 and 0.003 inch diametral. Ex;arience with the tubing manufacturer has shown that the tubing OD is cor.sistently larger than the minimum 0.625-inch and that the tubesheet holes generally tend toward the maximum dimension.
Expansion experience indicated that a maximum annulus should be the worst-case condition for leak and load-carrying ability. The 10-hole leak and load test mockups were gun-drilled to produce a diametral annular gap of 0.013 inch for the two heats and lots of tubing that will be used. At that point, the mainte-nance of surf ace finish in the gun-drilled holes was judged to take precedence over the necessity of producing a 0.016-inch gap, and the holes were not honed. It is felt that the 0.013-inch gap is very close to the maximum ex-pected in the steam generators.
In addition, separate tests performed on honed single-hole mockups confirm that the configuration of the 10-hole mockup (annular gap) is representative of worst-case conditions (section 2.6.3.1).
~
2-10
~
-~
~^
2.3.2.1.
Xinetic Expansion Testing The objective of the kinetic expansion process is to establish an essentially leaktight, load-carrying joint within the upper tubesheet of the TMI-1 steam generators below any existing tube defects.
2.3.3.
Cyclic Loading The initial design life objective for the tube kinetic expansion is 5 years.
Cyclic testing and/or analysis were perfonned during the qualification program to satisfy this objective. The key transient parameters that can affect the joint integrity (such as thermal cycling) were tested as part of the qualifica-tion program.
A design life of 35 years has been established as a goal. The qualification program will include test specimens for cyclic testing to a 35-year life sepa-rate from thoe: used to qualify the repair for 5-year life. These specimens I
will be tested using the same key parameters but with greater numbers of cycles in order to satisfy the 35-year life goal.
A sumary of the transient cycles to be used from OTSG function specification CS(F)-3-33 is attached as Table 2-1, and the analysis is discussed in section 2.4.2.
These objectives are consistent with section 3.8 of reference 9.
2.3.4.
Transition Stresses The kinetic expansions will not be stress-relieved, and this raises the con-cern that the residual stresses may make the repaired areas more susceptible to stress corrosion cracking. During manufacture the steam generators were l
hydrotested after' stress relief. Leaking tubes were re-rolled to make a tem-porarv seal until.the hydrotest was completed and the leaking tubes zould be rewelded. This resulted in about 150 hard-rolled' tube joints going into ser-vice without post-roll stress relief. Thes'e joints have had about 5 years of satisfactory service, and 10 were specifically-examined inlower tubesheets at l
TMI-1 to assure that there was no evidence of cracking in _the roll transition.
t l
In addition, three $ ample tubes in an Oconee 3 steam generator were itnetical-ly expanded for tihe full length of-the tubesheet to close the crevice. These l
tubes have been in service since the early 1970's without evidence of leaks or l
eddy current indicatiions. This operational data combined with residual stress l
?
y 2-14 w
~
.,, ~
_ C. E. "., 7 T ~,._. _. -.. =. _
~
measurements and corrosion testing (see section 2.8.1.2) provide adequate as-surance that the repaired areas can operate successfully for many years with-out becaming defective due to stress assisted corrosion cracking in the expan-sion.
One design objective cf the repair program is to maximize repair life by mini-mizing residual stress in the transition region between the expanded and un-expanded portions of 'the tube (section 3.6.1 of reference 9). Since an abrupt tran.ition produces higher residual str?sses and larger stress concentrations, it is required that the transition length be longer than 0.1 inch. A transi-tion length between 0.125 and 0.25 inch was established as a goal.
(Section 2.4.3 includes a discussion of residual stress analysis.)
{
An additional objective of maintaining residual tensile stresses (both circum-
~
ferential and axial) in the transition at less than 45% of the 0.2% offset yield stress at room temperature was established (section 3.6.2 of reference 9). Residual stress measurements of the transition region have been docu-mented during the qualification program. The electrochemical tests with 10%
cau.stic solution (section 2.8.1.2) also provide evidence of acceptably low residual tensile stresses.
2.3.4.1.
Residual Stress Testing (Proprietary)
A preliminary test was done at Foster Wheeler to establish expansion param-ete s that would lead to a smooth transition area, thus minimizing residual i
l stresses. Several insert shapes, shown in Figure 2-11, were evaluated to de-tennine which provided a smooth transition of 0.125-to 0.25-inch length. The resulting transition slopes are plotted in Figure 2-12.
The insert, with a 30-degree chamfer on the end, was selected as yielding the most satisfactory transition shape.
Residual Stress Measurement l
Qualification tests were done at Pennsylvania State University to quantify the l
residual stresses at the inner tube surface in the transition region of kinet-ically expanded specimen tubes, using both high and low yield strength tubes.
A combination of X-ray diffraction and strain-gage techniques was used to de-tennine the residual stresses. Strain gages were mounted on the tube inner surface. The tube was removed by cutting the tubesheet, and then the tube 2-15 T
~-" -
- y*,_,.
. _ _ "~ -
-g.
itself was split. The strain changes during the cutting operation were con-verted to stress changes. The X-ray diffraction method was then used on the
_1 tube inner surface to measure the residual stresses in the cut piece. The total residual stress on the tube inner surface was determined by subtracting the stress changes during the tubesheet-cutting and tube-splitting operations from the X-ray diffraction measured stress. Since it was not possible to ob-tain a detailed description of these res' dual stressas, simplified analyses were perfonned to obtain approximate magnitude and distribution of the resi-s dual stresses.
The X-ray diffraction measurements; indicated high surface stresses on the order of double the tube yielo' stresses due to the tube fabrie.ation process.
Electropolishing to remove 2 to 3 mils of r slittet tube portion of the spect-mens confirmed that this was,'n local. surface phegomenon and the high surface stresses were only skin deep. Electropolisned specimens indicated sctual re-sidual stresses more consistent with expectations based on strain ga'ge' measure-ments. The results are tabulated in Table 2-5 and sketched in Figures 2-12a and 2-12b. The residual stresses measured using the' X-ray diffraction and electropolishing technique give stress-to~ yield ratios that slightly exceed the 457. repair goal.
In general the residual st'ress is about half the yield stress of the tube material. ;
~
2.3.5.
Effects of Kinetic Expansion s'
Foster Wheeler has used the kinetic expansien process'in ma'ny applications quite similar to this orie, i.e., expansion of tubes'tithick tubasheets of
~
heat exchangers. The success of these applications shows..that the general
~
effect of the acoustic pressure wave due to the explosive expansion'is not detrimental to the tubesheet. Strain gages were placed on a full;s~ize test generator to ensure that in this particular application the explosive expan-sion would not excite the tubesheet dr'g'enerator at,a natural frequency and thus cause unacceptable stress. Strain gages were placed on the tubesheet, on the tubesheet/shell weld, and on one tube. The-gage locations are shown in Figures 2-44a and 2-44b. The data storage equipmerit was capable of recording data at frequencies up to 8000 Hz. Review of thJ data indicates that maximum strain readings were recorded at or below 800 }iz. This is the approximate
~
natural frequency of the upper tubesheet,
s 2-16 m.
,3
~
~~~
E
-s.
__.-_.7 The maximum stress recorded during expansion of the 132-tube row at the mid-
~~
line of the generator occurred at strain gage location 3d in Figure 2-44a.
This gage was the one closest to the expanded tube row. The nieximum stress intensity was 95,000 psi, and the maximum stress intensity at the tubesheet/
lower shell weld was 14,100 psi. These capare to the tubesheet yield strength of 67 to 70 ksi. Since the yield strength of steel increases marked-ly at high strain rates (up to twice static yield) no plastic defomation should have occurred. A fatigue analysis of the tubesheet and welds was per-formed, with the result that the calculated fatigue usage for the entire ex-pansion process (expansion of all rows twice) is less than 0.12.
A uniaxial strain gage was also placed on one side of one of the tubes to be expanded. As a result, the gage recorded the combination of bending and axial stresses. The maximum stress, approximately 6000 psi, was recorded when the
~~
tube was expanded. The very low stress indicates that neither the tube nor
['
the generator internals are excited significantly.
In addition, within the measurement sensitivity, no residual stress was recorded, indicating that no change in tube preload occurred.
In addition to the strain gage data, the tube /tubesheet welds and surrounding cladding were inspected and examined by liquid-penetrant techniques. No crack indications were found.
2.3.5.1.
Effect on Welds
~
During the full-scale OTSG kinetic expansion test at Mt. Vernon, strain gages were placed on the shell/tubesheet weld' of the lower end of the upper tube-sheet. No adverse effects were noted, even for the simultaneous expansion of 130 tubes. Since all tubes in both generators will either be kinetically ex-panded or removed from service, no analytical or test work was perfomed to examine the effects of the kinetic expansion on the original seal and load car -
rying tube /tubesheet welds except for a few samples checked by liquid pene-trant after expansion which showed no degradation.
2.3.5.2.
Adjacent Holes Effect (Proprietary)
The adjacent hole effect was also found to be small for the range of charge sizes under consideration. Only minimal change was noted in the diameter of 2-17 u
. ~+,-,.-*
4-
.~.--w
These tests led to the conclusion that kinetic expansions have no significant effect on tubeshcst integrity. No evidence of sipificant ligament distortion or tubesheet bowing nor any evidence of fatigue failures have been noted.
For individual expansions, evaluation of the tubesheet ligaments has shown no significant ef fects of expansion. However, it has also been postulated that with multiple kinetic expansions, the shock wave could be reinforced so that the sequence of explosions or the length of the primer cord should be con-trolled to ensure that the tubesheet is not overstressee. The concern is that the shock wave may travel at about the speed of sound through the material, and if adjacent tubes explode in a manner so that their shock waves reinforce those from other tubes, a condition could be caused where the tubesheet is 4
ove rstressed.
m Neither Foster Wheeler experience nor the method of detonation supports this postulatt.d concern. Foster Wheeler has kinetically expanded tubes in over 2000 feedwater heaters and has expanded as many as 5000 tubes in a heater in
- 2 one detonation. They have experienced no tubesheet overstressing problems, p
and they do not believe this is of concern since the plan is to expand no more L
than 137 tubes simultaneously for the TMI-1 steam generator repair.
l ',
It should be noted also that the cords connected to the tubes to be expanded simultaneously are bundled to be approximately the same length, so that adja-cent candles explode together rather than sequentially along the row.
2.3.5.6.
Effect on Plugged Tubes w
The TMI OTSGs have tubes that have been taken out of service by four different procedures. A concern has been raised as to how the planned kinetic expansion may affect these pluggd tubes. The following four procedures have been used:
1.
Explosively wclded plugs.
2.
TIG welded piugs - plugs welded to the tube ends or tubesheet at the top
(
of the upper tubesheet.
l Hydraulically expanded tubes sealed with a TIG-welded plug - tubes that 3.
have been stabilized by expansion after a short section of the tube with-in the tubesheet was removed. The tubes were then taken out of service by installing welded plugs in the tubesheet openings.
4.
Mechanically rolled plugs.
l 2-19 l
l The established acceptance standard for leakage was 2.5 drops per minute for each plugged tube. The plugged tubes in the test blocks were hydrostatically tested prior to kinetic expansion and were found to have zero leakage. After kinetic expansion, each block was found to have less than 0.1 drop per minute leakage during hydrostatic testing.' This campares quite favorably with the original rolled plug qualification tests, 4tch showed 8.0 drops per minute per four-tube block.
The established acceptance stardard for the pullout load on rolled plugs was 3000 lb. The average pullout load in the original rolled plug qualification by WCAP was 4645 lb. After kinetic expansion of the surrounding tubes, the rolled plugs in the test blocks were found to have a mean pullout load of 4842 lb, with a minimum of 3750 lb and a maximum of 5220 lb. This confirms that the kinetic expansion process has no significant effcct upon the pullout strength of rolled plugs.
The inside diameters at the end of all tubes were recorded prior to plug in-sta11ation, and after expansion the plugs were removed and the inside diam-t-
eters were again measured. The change in diameters was found to be minimal 7-u for both unplugged and plugged tubes. The high and low yield unplugged tubes showed changes in inside diameter of 0.00030 and 0.00034, respectively, af ter
{
expansion. The high and low yield plugged tubes showed changes in inside diam-eter of 0.00034 and 0.00065, respectively, af ter expansion and plug removal.
The surface of the removed plugs showed medium to medium-heavy galling. The inside of the tubes which had been plugged showed fine longitudinal galling due to the galled plug surface and some intennittent rust-colored stains.
~
The conclusion is that the ef fect of kinetic expansion of tubes surrounding tubes that have been plugged by rolled plugs is acceptable and the rolled plugs continue to meet the acceptance criteria to which they were originally qualified.
2.3.5.7.
Effect of Unidentified Misfires
'~
During the kinetic expansion process, occasional misfired inserts were ejected from the tubesheet (jumpers). The cause of ejected misfires was thought to be a whipping action of the ordnance transfer cords in which sufficient kinetic energy was imparted to the conis by the detonating inserts to pull a misfired 2-21
~ - - - -
~ _ -. _ _ _ _ _ _ _.. _ _ _ _
the tube under some conditions. A bowed tube could conceivably wear against a neighbor and cause a rupture of that tube. An analysis has been made that indicates that plants can safely shut down in the event of a tube rupture, and radiation exposure at the uclusion area boundary would 1
be insignificant.
2.3.5.8.
Tube Blistering Obrigheim Tube Blistering The Obrighem recirculating type steam generators have a 26.57-inch-thick tube-sheet with Inconel cladding on the primary face.17 These steam generators were constructed with three hani rolls within the tubesheet; each roll is about 3 inches long. They are located at the bottom, middle, and top of the tubesheet, with an 8.8-inch-long unexpanded zone between the rolls (Figure 2-47).
ID-initiated tube cracking has been detected in the roll transiticn of the up-per two rolls. This appeared initially in 1970 and has continued at a slow pace every since. In 1981, eddy-current inspection of 707, of the tubes in steam generator 1 (1440 tubes inspected) showed that 150 tubes had blisters in the trapped space between the second and third hard rolls. Some of the bli s-l ters projected about one-third of the way across the tube inside dicmeter.
The perception of the Obrigheim personnel is that water from the primary side leaks through the roll transition cracks and fills the space between the rolls.17 Then, during subsequent heatups, the water expands at a rate faster than it can leak back, so that the tube is plastically defomed. It was not l
r l
known whether this occurred during a single transient or over a nunter of transients. However, our analysis of the program indicates that a substantial number of cycles would have been required. Also, it should be noted that Obrigheim was operated for a number of years - probably with some very small l
?
tube cracks - before the blistering was observed, and no serious operational problems were incurred.
Evaluation of Tube Blistering The size of the tube-to-tubesheet gap is the critical parameter in preventing tube blistering. If the gap is small enough, the pressure due to thennal ex-pansion of the water will be relieved by elastic deformation of the tube and 1
2-23 l
l l
~*-)
T. _ _..Z
~
~~
tubesheet. The following analyses were perfomed to detennine the limiting gap size to prevent blistering:
1.
The ability of the tube to withstand external pressure without plastic defonnation was evaluated by conventional stress and buckling analyses.
2.
The elastic response of the tube and tuoesheet to crevice pressure was i
evaluated using the methods and equations in reference 19.
For the TMI-1 OTSG tubes, it was found that the gap must be limited to about 1 mil to be confident that blistering would not occur-Since the TMI-1 nominal radial gap is 5 mils, the crevice must be closed. The kinetic expansion pro-cess is acceptable because it results in a tight gap with no large crevice like that at Obrigheim to trap water.
2.4.
Analyses Analyses were perfomed to evaluate the effects of the repair process on the 0TSG. These analyses were perfonned with the following objectives:
To detenkine the effect of kinetic expansion on plant perfonnance.
To detennine the loads on the steam generator tubes as a result of normal operation, expected transients, and accident conditions.
To detennine the expected strength of the kinetic expansion joint.
To evaluate the potential for flow-induced vibration of the tubes.
2.4.1.
Plant Performance Kinetic expansions will have no effect on OTSG thennal-hydraulic perfonnance and thus no effect on plant perfonnance. The basis for this judgment is two-fol d.
First, since no credit is taken for heat transfer between the tube and tubesheet, kinetic expansions within this tubesheet will cause no change in OTSG or plant thennal output. Second, B&W has qualitatively assessed the ef-fect of tube expansion within the tubesheet on pressure drop, and hence on flow in the primary system, and has judged tha effect to be negligible. The judgment was based on geometric comparison of the kinetically expanded tubes to previously analyzed sleeved tubes (see section 3.3 of reference 9).
~
2.4.1.1.
Tube Shrinkage Under Accident Conditions During the kir. etic expansion nualification program, it was decided to limit the length of the longest polyettylene insert.to 22 inches. This decision was based on ensuring that a tube with a 360-degree defect at the new transition would not disengage fran the upper tubesheet during transients or accidents.
2-24 6
,,,pgw,,,g-w,,,---m-*-
e
_e..-%
2.-.
The controlling accident is a main steam line break (MSLB). It has been shown
~
that during a MSLB a tube could shrink approximately 1 inch compared to the distance between the upper and lower tubesheets:
Change in length = 0.16% x 54 ft x 12 in'./f t
= 1.0368 inch Thus a 1-inch tube shrinkage would still allow 1 inch of engagement within the upper tubesheet if the tube severed at the expansion transition, which is suf-ficient to restrain the tube from lateral movement.
l 2.4.1.2.
Tube-to-Tubesheet AT Under Accident Conditions As part of establishing the worst-case pullout load, an analysis was performed to compare the accident condition that produces the highest tube-to-tubesheet AT (LOCA at a relatively low load) to the accident, MSLB, that produces the highest load at a relatively low aT.
The MSLB proved to be the worst-case condition. This is primarily attribu-table to the fact that the high AT noted in the LOCA event occurs significant-
[~
ly before (at less than 1 minute into the event) the maximum LOCA loading (noted at about 5 minutes elapsed time).
2.4.2.
Load Conditions 2.4.2.1.
Normal Operation and Tran:1ent Tube Loads The loads on the steam generator tubes are a result of primary and secondary system pressure and temperature effects. Because of the different materials -
Inconel for the tubes and carbon steel for the shell - overall temperature change as well as temperature differences between parts causes loads to be ex-erted on the tubes. Only a limited number of transients generate significant tube loads: these are listed below with the tube load resulting from each.
Reference 47 discusses this analysis, and Table 2-2 lists the results. (A positive number indicates a tensile load and a negative number indicates a j
compressive load.)
l 2-25
'~*~
e-
+
~.
7 _. _ _ _ _ _ _ _
No.
Transient Lead, Ib 1A Heatup from cold shutdown to 0% power
-775 1
18 Cooldown from 8% power to cold shutdown 1107 2A Power change, O to 15%
-525 2B Power change,15 to 0%
143 i
3 Power loading, 8 to 100%
-419 4
Power unloading,100 to 8%
-100 2.4.2.2.
Accident Condition Tube Loadji, Three accident conditions cause significant loads on the steam generator tubes: large break LOCA, main steam line break (MSLB), and feedwater line break (FWLB). The axial loads on the tube are as follows:
Event Load, lb LOCA 2641 Main steam line break 3140 Feedwater line break
-570 OTSG temperatures and pressures at the time of maximun tube-to-shell T were determined. for the accident conditions. Mechanical tube loads were calculated fo.' the center and outermost tubes by an axisymetric structural analysis (NASTRAN). The dynamic effects of secondary side pipe breaks (MSLB and FWLB) are negligible. However, the combined LOCA and SSE (safe shutdown earthquake) accident includes a coment load of 18 in.-lb derived from the tube deflection, making the axial tube load 337 pounds during the combined accident. Steam cross flow through the upper span during an MSLB accident would be quite high, causing the maximum flow-induced vibration displacement of 0.125 inch, which yields a maximum bending moment of 104 in.-lb during tube-to-tube contact with an assumea flow-induced vibration mode shape. Reference 47 discusses this l
analysis in greater detail, and the results are given in Table 2-3.
2.4.2.3.
Thermal / Pressure Cycles As discussed above for nonnal operating tube loads, there are only a few tran-sients of interest - those that cause significant pressure or temperature fluc-tuations. The following transients need to be considered:
2-26
. ~. _ -, -.. _ _
~
=
No. of cycles for 40-year Transient plant desion life Heatup 240 Cooldown 240 Power change O to 15%
1,440 Power change 15 to 0%
1,440 Power loading 8 to 100%
48,000 Power unloading 100 to 8%
48,000 Step load reductions 310 Reactor trips 400
- Rapid depressurization 80 After the first 15 minutes, the rapid depressurization transient goes into normal cooldown and the plant is eventually returned to power via normal heat-u p.
The tube load results from the normal cooldown/ normal heatup portion of the transient cycle. Since this cooldown/heatup is already included in the 240 cycles of heatup/cooldown, the 80 cycles of rapid depressurization are not additive.
There are three modes of recovery from reactor trip t.ransients with a total of 400 design cycles. Of the 400 cycles, 340 are taken to be recovery from 540F, 20 to be recovery from 220F, and 40 to be recovery from 70F. Only the latter two represent significant temperature ranges. These two modes represent a total of 60 cycles. Since the temperature ranges from these reactor trips are similar to and bounded by the range for the cooldown transient, these 60 cy-cles can be added to the heatup and cooldown transient cycles.
Similarly, step load reduction cycles can be added to the power unloading cy-cles since the temperature range for the power unloading transient bounds that of the step load reduction transient. This results in the simplified table of design cycles to be used for analysis of the expanded joint.
l 9
m i
j l
l 2-27
Wall Radial Transition Case thickness, di splacement,
- length, End conditions
- No.
i st. _
in, in.
Top 20ttom N1 0.034 0.010 0.0625 Free Rollers N2 0.034 0.010 0.6250 Free Rollers
~~
0 0.034 0.010 0.0625 Rollers Rollers P
0.034 0 010 0.6250 Rollers Rollers Q
0.340 0.010 0.6250 Free Rollers
- In these stress models, the tube is inverted so that the bottom end in the model is actually the top of the OTSG tube.
These analyses show that the 0.0625-inch transition length produces abrupt changes in stress distribution within the transition zone (see Figure 2-23 and 2-24). Transition zone is shown with an expanded scale in Figures 2-25 and 2-26.
Of particular concern is the fluctuation in av.ial stress, which has a range of -1500 to +800 ksi at the inner surface of the transition. The 0.625-
~~
inch transition has a much smoother stress distribution, cs shown in Figures 2-27 and 2-28.
In this case, there is minimal fluctuatior, of axial stress; it ranges from +50 to -100 ksi. Figures 2-29 through 2-34 show taat a change in
~
end conditions has no s'ignificant effect on the stress distribution. Note
-s that these high values of stress ate not representative of the stresses in the real joint; they result from the assumption that the tube reponds in a purely elastic mode, i.e., they are pseudo-elastic stresses.
An additional case was run with a wall thickness of 0.3? inch to determine whether tube wall thickness is a critical parameter. Figures 2-35 and 2-36 show that an order of magnitude increase in the wall thickness does not sig-l nificantly affect stress distribution.
It is concluded that radial tube dis-l placement and transition length are the critical parameters.
l Plastically Deforned Model With Interfacial Pressu.e Load In these analyses, the tube was modeled with a 10-mil plastic radial displace-ment within the expanded region (Figures 2-37 and 2-38). The transition was modeled with lengths of 0.0625 and 0.625 inch as before.
In addition, a pres-sure of 3350 psig was imposed at the outer tube surface in the expanded region to simulate the interfacial pressure between the tube and tubesheet. This is the calculated interfacial pressure that will produce the strongest joint, i
2-30 y
n vo-
,..-p e.-e
,,,m
,,- --~.-
n, nn-r
+.-~
--e---
v--
^
~
1.e., the highest pullout force, for the TMI-1 tube and tubesheet seemetry, a 1-inch long expansion, and a tube yield stress of 35,000 psi. The equation used in this calculation is fram reference 16. The following cases were run:
Radial Transition Case di splacement, le ng th, End conditions No.
in.
in.
Top Bottom l
R 0.010 0.0625 Free Rollers S
0.010 0.625 Free Rollers U
0.010 0.0625 Rollers Rollers The results of these analyses are shown in Figures 2-39 through 2-44.
They demonstrate that the distribution of the stresses from plastic deformation and interfacial pressure are independent of transition length. They also show that changing the top end connection in the model from free to rollers has no significant effect on stress distribution.
Ccnclusions (Proprietary)
The plastic analyses do not indicate a strong dependence of transition stres-ses on transition length over the range of transition lengths from 0.0625 to 0.625 1,nch. However, in the interest of minimizing the transition stresses and stress concentration factor, it was concluded that a transition length between 0.125 and 0.25 inch should be established as a goal, and that the mini-mum acceptable transition length is 0.1 inch. Preliminary tests have shown that a 30-degree chamfer on the end of the polyethrlene insert will produce a transition length of about 0.3 inch. Inserts with this taper are being used for the repair.
2.4.3.2.
Alternate Analysis In addition to the GPUN residual stress analysis described above, Foster Wheeler performed a modified finite element analysis of the kinetic expansion l
process. The analysis was based on the assumption that the explosive forming creates an internal pressure pulse distributed uniformly in the tube up to a length equal to the length of the explosive device. In this analysis, the j
pressure pulse was applied statically in the tube and tubesheet assenbly model. Two in-house canputer programs were used in the analysis:
M 2-31
- - ~ - - -
7
1.
The first program performs a generalized plane-strain elastic-plas-tic analysis of two concentric, thick-walled cylinders with an ini-tial gap between them. This program was used to estimate the magni-
-~
tude of the pressure pulse. Several magnitudes of the pressure were analyzed, and the one that resulted in the experimentally measured internal diameter of formed tube was selected for further analysis.
The displacement history of the centerline of the tube was deter-mined for the selected pressure and is used to analyze the transi-tion region using the second computer program.
2.
The second program performs an elastic-plastic analysis of a semi-infinite, thin-walled tube subjected to displacement on a part of its length. The displacement history determined by the first pro-gram was imposed on a small length at the end of the tube. The stresses and deformation at the end of the displacement history were determined at *averal points in the transition region.
These analyses were performed to provide a point of reference for the test work on residual stress done at Pennsylvania State University (section 2.3.4.1).
The results of the Penn State tests gave good agreement with the analyses performed by both GPUN and Foster Wheeler for 00 stresses. Howave r, the Penn State data showed high tensile residual stresses in the ID at the transition zone of the expansion and in che tubing below the expansion.
The results of earlier work performed by B&W Canada, comparing residual stres-ses in hydraulically expanded Inconel 800 to mechanically rolled tubing (de-scribed below), led to the conclusion that the ID stresses noted in the Penn State tests probably were skin effects (less than 3 mils deep) and were most likely due to the extrusion process used in forming the tubing during manu-facturing and subsequent straightening operations. A test of unexpanded tubing verified that the tensile ID stresses are present in the tubing prior to expansion.
Supporting the belief that the ID stresses noted were residuals of the tubing manufacturing process was the fact that the heat treatments performed on the l
assembled steam generators were aimed at stress relief of the carbon steel shell. The 1100F temperature did not approach the 1600F range needed to fully anneal Inconel 600. Therefore, while this heat treatment might reduce resid-ual tensile stress produced by tubing manufacture, the temperature was too low to eliminate it entirely.
i 2-32 w
In 1981, as part of a davelopment program for a hydraulic expansion tool, B&W compared residual stress developed in a hydraulic expansion of an Inconel 800 steam generator tube in a carbon steel tubesheet to the stress from a mechan-ically rolled joint with the same combination of materials. Roll expansion produced high tensile stress in both the axial and circumferential directions.
Hydraulic expansion produced higher tensile stresses in the circumferential direction but only compressive stress axially. The circumferential stresses were only skin deep, changing to compressive within 1 mil of the surface. Pre-expansion heat treating reduces or eliminates circumferential stress depending on the treatment temperature; i.e.,1125F for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> reduced tensile stres-ses,1600F for one hour produced only compressive stress.
While the kinetic expansion is considered to be somewhat comparable to the hy-draulic expansion, these tests are of limited use for drawing conclusions about the TMI-1 steam generator repairs. Since kinetic expansions were not tested, only 0D stresses were measured, and the work was performed on Inconel 800, not Inconel 600. The results, however, are consistent with the analyses perfonned by GPUN and Foster Wheeler and the Penn State test data for 00 stres-ses.
2.4.4.
Margin of Stability and Random Flow-Induced Vibration The tubes in the sixteenth (uppennost) span of the TMI-1 OTSGs have been eval-l
^
uated with regard to dynamic instability and the margin of stability was assessed.
Margin of stability is defined as the ratio of the calculated critical veloc-ity, Vc (velocity in the gap between tubes at which unstable motion of the tubes would occur) to the actual average gap velocity, V. The ratio of Ve to g
Vg must be equal to or greater than 1.0 for stability, and the margin is the l
percent by which the radio exceeds 1.0.
For example, if Ve/Vg = 1.3, the mar-gin of stability is 30%. The critical velocity is calculated by a Conners-type fonnu:a as follows51.
V
'm/
o. s - h (1)di
~8 5
2 K6 " c y gyzyuazzygg 2-33 l
y.,
y 7
where Ve = critical tube gap velocity at which tubes become unstable,
- fps, fn = lowest nth mode tube natural frequency for the span for which V is calculated, Hz (cycles /second),
c D = tube diameter, ft.
C = threshold instability constant, dimensionless, me = weight of tube per unit length including added weight of fluid outside the tube, lbm/ft, 6 = logarithmic decrement for tube vibrating in the nth mode of vibration, equal to [2r (percent damping)/100].
3 p = weight density of fluid, lbm/ft,
$n(f.) = relative tube amplitude of the nth mode as a function of the distance along the span of length U(1) = relative crossflow velocity along the span of length
= local velocity divided by average velocity,
[]' 5 = mode shape and velocity profile factor.
TMI-1 is rated at 2568 MW, while TMI-2 is rated at 2772 MW. The lower power level results in smaller average gap velocities, which in turn tend to in-crease the margin of stability. _THI-1 has an external AFW header, while other 177-FA plants (Davis-Besse, Rancho Seco, and Oconee 3) have internal AFW head-e rs. With the external auxiliary header, the peak velocity of the cross flow velocity profile is about 5 inches above the tube midspan. With the internal auxiliary header, it is about 10 inches above the tube midspan. The location of the peak velocity affects the velocity profile and mode shape factor of the Conners-type formula. The factor is 1.30 for the internal auxiliary header
~
arrangement, and 1.00 for an external header. Thus, the external header de-sign results in a lower critical velocity and a lower margin of stability.
Based upon the above facts OTSGs that have external AFW headers and operate at 2568 MW would be expected to have tubes with a smaller margin of stability than those in OTSGs with internal AFW headers operating at 2772 MW.
- However, operating experience in plants rated at 2568 MW indicates that TMI-1 tubes with frequencies and boundary conditions equivalent to the pre-repair condi-tions should not become unstable.'
Measured flow-induced random responses from instrumented TMI-2 tubes varied as a velocity squared function. Tube displacements varied as a function of tube 2-34
.m
location and power level. The lower steam rates for TMI-1 are expected to re-sult in random flow-induced tube displacements that are less than the displace-ments of the TMI-2 tubes.
2.5.
Joint Strength Testing This test program complies with the requirements of seccions 4.3 and 3.5 of reference 9 and encompasses pullout strength testing and preload carrying capability.
2.5.1.
Pullout Tests Axial load qualification tests were perf?rmed to verify the adequacy of the kinetic expansion process parameters. Eight 10-tube nockups were processed as outlined by a Logic Chart (Figure 2-16).
The repaired tube must sustain the maximum design basis axial tensile load of 3140 pounds from the generic 177-FA MSLB accident analysis. Satisfying this criterion requires no relative movement (slippage) between the expanded area and the tubesheet during the 3140-lb MStB tube load. The load of 3140 pounds given in BAW-10146 is applicable for TMI-1 since the report is a generic topical.47 The loads on the steam generator tubes are caused primarily by differences in temperature and coefficient of thermal expansion between the tubes and the steam generator shell. As such, the loads are strain-controlled. The main' steam line break (MSLB) load, which is the greatest load imposed on the tubes and thus the test Icad for the joint, is calculated on an elastic basis and is the result of 0.16% strain. The use of the elastic modulus to calculate the load is conservative, as shown in Figure 2-1.
l The coefficient of thermal expansion of the Inconel tube is greater than that of the tubesheet. This results in a greater seating pressure in the joint at operating temperature than at room temperature. For loads in the elastic l
j range of the tube, which includes all the cyclic loads, the joint would be i
more resistant to slip at operating temperatures than at room temperature.
Hence, the mechanical load cycling can be done at room temperature.
l
\\
2-35 i
~~
The objective of leak testing per section 4.4 of reference 9 was to document, with 99% probability at a 99% confidence level, that the kinetically expanded joint has leakage less than 3.2 x 10-6 lb/ hour per tube at operating condi-tions (primary temperature 604F, primary pressure 2155 psig, and secondary' pressure 925 psig). The leak rate was determined based on the pressure decay of a known volume test system at constant ambient temperature.
During the leak rate testing, an initial period of time was allowed for the joints to " season" in recognition of the fact that tight rachanical joints of this nature tend to self-seal with time.
The differential pressure ased during leak rate testing starts out high enough so that the average AP 6cing the expected test duration is comparable to the nomal operating aP of 1275 psig.
I 2.6.2.
Mock-Up Processing Leakage qualification tests were perfomed to verify the adequacy of the kinet-ic expansion process parameters. Eight 10-tube mockups were processed as out-lined by a Logic Chart (Figure 2-16).
The'mocEups for testing the leak-liraf ting ability of the repair were expanded using detonating cord ignition of the expansion device instead of the ordi-nance core / booster ignition system will be used in the actual repair. This type of ignition for the test blocks does not create test conditions that are non-representative of actual conditions for the following reasons:
The effects of kinetic expansions have virtually no longitudinal (axial) com-ponents, as shown by pre-TMI-1 tests by Foster Wheeler, Mt. Vernon tube strain gage measurements, and the induced-strain portion of the qualification test-ing. Therefore, in the generator the booster has no effect on the balance of the expansion, especially the lower 6-inch qualified length.
In the tests for leak and axial load, the purpose was to test only the quali-fied length (i.e., the bottom 6 inches of the expansion). The tubing was ar-ranged in the mockup to simulate 360* through-wall crack, which produced the 6-inch qualification length. Therefore, the state of the expansion above the qualification length had no effect on the test. Because of this, the use or non-use of the boostar for this test is irrelevant.
2-44
=.:
_ 7 _ __
,l I
Leak tests are also perfonned at rom temperature rather than at design or op-erating temperature. The higher seat pressure at higher temperatures makes the joint more leak-resistant. These factors cambine to make roos ternperature testing conservative. Another conservatism is that.the tests are perfonned after the joint has been subjected to tne total number of mechanical and thermal cycles expected for the complete five-year qualified lifetime of the joint.
The eight 10-tube mockups (Figure 2-19) were expanded by the chosen technique and then tested. The tubes were inserted into 12-inch-high tube blocks from the top and bottom, meeting 2 inches below the top of the block. Therefore, the point where the two tubes meet represents a 360* through-wall crack. The 2-inch stub tube was roll expanded and then the two tube assemblies were ki-netically expanded to a depth of 8 inches from the top, providing 6 inches of seal below the simulated crack.
All blocks but one were thenna11y cycled with 38 cycies of 70F to 610' and back to 70F to represent five years of heatup and cooldown and eight reactor trip s.
Block SP-1 was then exposed to the following series of load cycles se-1ected to correspond to the five-year qualification period:
100 cycle 780 lb capression to 1110 lb tension
~
180 cycles 635 lb compression to 175 lb tension 6000 cycle 510 lb cmpression to 125 lb conpression Leak tests were performed using demineralized wa.ter at 70F with 1275 psig pres-sure on the primary side, simulating primary-to-secondary OTSG differential pressure. One additional test of 10 expanded tubes was conducted at 70F with 1275 psi pressure on the secondary side, and another test used 2500 psig at 70F on the primary side. Yet another block was leak-tested at 400F and 1275 psig on the primary side.
Finally, one block with one twice-expanded tube was leak tested at 1275 psig
~
at 70F on the primary side. Four tubes in this block had received. the extra af ter hits.
Two bubble tests were conducted at 70e using 150 psi nitrogen pressure on the secondary side. Tubes in one block were pulled before any conditioning to pro-vide baseline data. After cycling and leak testing, all enaining tubes were tested to determine pullout loads.
l 2-45 c
a
a
~
4 Leak and slip tests in the qualification program utilized a minimusi expected defect-free tubing length of 6 inchess. In the steam generators almost all tubes will have much longer defect-free expansions - up to about 15 inches for many. 'As a minimum, the leak rates for such tubes should be reduced as the length of the leak path increases. Also, as the length is increased, discrete leak paths will be sealed off, producing a further reduction in total leak rate. While it is not possible to predict what the leak rates will be in the generators, it is expected that they will be much less than indicated by the extrapolation of qualification test results.
2.6.3.
Leakage Test Results 2.6.3.1.
Preliminary Tests Air Leak Tests (Preliminary Testing)
To obtain a quick report on the relative leak tightness of the expanded tubes, all expansions were subjected to a soup. bubble test using 100 psig gas.
In general, tubes with low pullout loads also leaked in the bubble test although all tubes that showed leakage did not have low pullout loads. The major func-tion of the gas leak test was to give a qualitative indication regarding the results of a future water leak test at 1275 psig.
~
~
~
~
Water Leak Tests (Preliminary Testing)
The water leak tests were conducted by subjecting the expansion to an initial water pressure of 1400 to 1500 psig. Several tests of different durations ranging from 15 to over 50 hours5.787037e-4 days <br />0.0139 hours <br />8.267196e-5 weeks <br />1.9025e-5 months <br /> were performed. A qualitative conclusion ob-tained from these tests was that expansions that leaked with 100 psig gas also leaked water in excess of the 3.2 x 10-6 lb/h per tube limit. Also, a very small appearance of foam, or a no-air leak result gave indications of water leaks that were within the allowable value.
Water leak calculations were made by observing the behavior of water pressure and temperature with time. It was found that even for an acceptable joint, the pressure decay (for several hours) was initially steep and sometimes took up to 36 to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> te arrive at a steady state decay rate. The leak rates were calculated using pressure and temperature data taken after this steady condition was achieved.
2-46
The results of limited water leak rate testing and 100 psig gas leak tests for each joint indicated that there were several possible charge sizes and combina-tions that could provide acceptable water leak rates. The choice of optimum charge size was dependent on other tests, particularly the pullout load tests.
Leak Testing of Selected Joint (Preliminary Testing)
Two water leak tests were perfomed on the 6-inch test expansions using pres-sure transducers and themocouples to monitor water pressure and temperature.
The water leakage rates were detemined using pressure decay after an initial curing time. The effects of water teaperature changes on water pressure were accounted' for in the leak rate calculations. In these two tests, after ini-tial curing, the water pressure and temperature varied as shown in Figures 2-20 and 2-21. The calculations show the leak rates to be essentially zero
~
for the two tests.
A third test used a pressure gage for water pressure measurement and a mercury thermometer to read ambient temperature (reasoning that the change in ambient temperature corresponds to changes in the water temperature with a small time lag). After initial curing the water pressure varied between 2010 and 1780 psig, while the ambtec.t temperature varied fra 70.5 to 70.0F over 70 hours8.101852e-4 days <br />0.0194 hours <br />1.157407e-4 weeks <br />2.6635e-5 months <br />.
Leak rate calculations show the upper bound leakage to be approximately 0.8 x 10-6 lb/h.
The water leak rate is measured using the pressure decay of an enclosed water l
volume under pressure, in which the first tem represents the pressure effect l
and the second tem represents the temperature effect:
leak rate = eV[(K + K')(dP/dt) + (S' - 8)(dT/dt)]
l where p = water de nsi ty,
V = water volume, K = isothemal capressibility of water, K' = structural elasticity of enclosure, s' = coef ficient for enclosure volume change due to temperature, S = coefficient for volumetric expansion of water due to tempe rature, GuS 2-47 s.-'bmew.
W9+$%. 9Agy wy_
-*h
7.-__.___..._-_
~
i dP/dt = rate of water pressure change, dT/dt = rate of water temperature change.
2.6.3.2.
Qualification Results Seven 10-tube blocks were expanded nonna11y and leak-tested with a 1275-psi minimum primary-to-secondary pressure at ambient temperature; leakage rates are plotted in Figure 4-17a. The tests on blocks C, D, E, G, H, A (test prior to re-expansion only), and SP-1 (test prior to axial load conditioning only) constitute a seven-test sample for evaluation of leakage. The average tube leakage was considered to be one-tenth of the total test block leakage in each The calculated leak rates fran the tests ranged fran 1.175 x 10-6 to case.
187.4 x 10-6 lb/h per tube. The seven-test sample had a mean leakage of 44.72 j
x 10-6 lb/h per tube, with a standard deviation of 64.76 x 10-6 lb/h per tube.
These statistics indicate a 99% confidence that 99% of the nonna11y expanded
]
tubes will have leakage rates no greater than 460 x 10-6 lb/h per tube. While this leak rate exceeds the test program objective of 3.2 x 10-6 lb/h per tube, it is still very low. If every tube in both OTSGs leaked at the expected mean rate, the cumulative leak rate would still be less than one three-hundredth of the Technical Specification limit of 1.0 gpm.
j The leak rate of block D showed an increase between 70 and 400F of about 10 x 10-6 ltm/h/ tube or 28%. However, this leak rate was dropped off rapidly and it appeared that it would approach the 70F leak rate after a few days. Leak rate is expected to depend to some degree on the interference pressure between the tube and tubesheet.
Effect of Annulus Siz2 (Qualification Test)
Six single tube test blocks were processed in order to evaluate the effect of annulus size on joint slip load and leak rate. Three blocks had the 0.016-inch maximum tube-to-tubesheet diametral gap permitted by drawing tolerances aM the other three had the 0.003-inch minimum pennitted. The large annulus samples had a mean leak rate of 285 x 10-6 lb/h/ tube and the small annulus sam-ple had a mean leak rate of 461 lb/h/ tube.
It appears that the greater accel-eration space of a large an ulus tends to result in a tighter kinetic expan-sion bond between tube and tubesheet with less leakage. The actual tube OD and tubesheet hole diameters both tend to be near the upper end of their toler-ance range, so the expected annulus size is 0.013 inch. Due to the different 2-48
.-eone s-
-u
+eiussen.-
..ue as-
,-.-.-g e.,
ma, m
--e.
-we w
_..i 11- _. - -
These tests established a kinetic expansion charge design and cleaning proce-dure that ensure that the chemical contents and amounts of residue after ex-pansion in the TMI-1 steam generators were acceptable from the standpoint of contamination. An organic booster substance was used so the field boosters were free of lead compounds.
The OTSG primary side was kept as clean as practical. As a minimum, such fluids as lut.-icants, cutting liquids, and flush water met the following standards, as specified by section 3.9 of reference 9:
Total maximum allowed level, Component ppe Sulfur 250 Halogens (Cl plus F-)
250 Heavy metals:
Arsenic 100
-1.e ad 50 Mercury 1
Solid materials used in the expansion process, such as for gaskets and seals,
~
met the same levels of total contaminants specified for fluids. The following materials were prohibited from use:
1.
Chlorinated solvents.
2.
Materials composed of materials containing halides or sulfides, unless allowed by special exception per reference 53.
3.
Fluorocarbon compounds such as Teflon.
The use of cloth, paper or cardboard products for temporary plugging and cap-ping purposes was prohibited. Only lint-free cloth was used for wiping and cleaning. The use of felt plugs for tube cleaning was acceptable. All loose debris was removed from the OTSG periodically. Special care was taken to pre-clude the lodging of debris in inaccessible areas. Most surface contamination was removed by wiping or by felt plugs followed by a flush.
m 2-53
\\\\\\\\\\ caustic corrosives until they concentrate and are present in much higher tem-peratures -- higher than 400F. Furthermore, almost all phosphorus compounds afe very soluble and will dissolve readily in the post-repair cleanup water.
I Thus', phosphorus, which is not a corrosive concern in itself, will be removed l
from the steam generators before operating temperatures are r eached.
2.7.2.
Moisture The crevice between the tube and tubesheet was heated to vaporize any water and drive out.the moisture. During the expansion process the crevice in the repair area was maintained at a temperature at least 10F higher than the dew point for secondary side conditions. Channel heaters were tested as the pri-2 mary equipment fo crevice drying. Cairod heaters are not intended to be a production drying process, but they were tested as an optional process for use in localized situations, 2.7.2.1.
Channel Heater Testing p
As part of the tubesheet crevice drying procedure, it was necessary to heat the entire upper tubesheet to a temperature of at least 130F with a requirement that no part of the tubesheet temperature exceed 350F..This test had the following objectives:
1.
To demonstrate the feasibility of heating the upper tubesheet to the required temperature using a B&W OTSG similar to the TNI-1 OTSG.
2.
To acquire heating and cooling data that would be helpful in performing l
the tubesheet heating of the TMI-1 steam generators.
3.
To demonstrate the effectiveness and field applicability of the heating units and monitoring equipment.
4.
To develop a workabla procedure for use at TMI-1.
Results and Conclusions u.
1.
The tubesheet could be heated to the required temperature; installation of the heating system and perfonnance of the test took approximately 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
2-55
-n
..n..
.w
2.
Heating the tubesheet to the required temperature took approximately 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
3.
Workable procedures to be used.at TMI-1 were developed, which reduced radiation exposure to a minimum.
2.7.2.2.
Calrod lleater Test (Preliminary Test)
The initial crevice drying tests in the THI-1 OTSG were Ifmited to two clus-ters of 13 tubes, using Calrod heaters. To demonstrate the technique, tests were perfomed to detennine the following:
1.
The equipment required to heat the tube and tubesheet hole in the OT!G to the desired temperature.
2.
Whether it was feasible to heat the tubesheet with 24-inch-long Calrod heaters.
3.
To develop a procedure for use at TMI-1.
Results and Conclusions 1.
It is feasible to heat small nunters of the tubes with the Calrod heaters.
2.
Procedures to be used at TMI-1 were developed.
3.
This test detennined the effect of heating on tube defect growth /propaga-l tion. Tubes were eddy-current tested before and after heating, and no f
changes or crack growth were observed.
~
2.7.3.
Residual Sulfur (Proprietary)
Objective The objective of this test was to assass what happens to the sulfur on the sur-l face of steam generator tubes after tDe tubes are subjected to the kinetic ex-pansion process. The ef fect of Immunol precoat material on the sulfur removal process is discussed in section 2.9.3.3.
l Test Descriotion Three samples fran two tubes removed fran the OTSG were exami,#. by Auger elec-tron spectroscope for sulfur concentration on the ID of the tubes, both before and af ter the explosive expansion. Concentrations were measured at depths of 0,100, 500,1000, and 500 angstroms.
l 2-56 l
i 2.9.1.
Debris Characterization The debris resulting from the expansion does not present a concern from a con-tamination standpoint due to the controls on the materials used in the produc-I tion, and maintenance of cleanlinees during fabrication and packaging. These controls ensure that contamination is not present in the expansion assemblies l
(section 2.7.1).
2.9.1.1.
Debris Analysis A section of detonating cord was set off in a 48-inch piece of tubing with the ends partially closed to capture the debris. The cord used was a 25 grain /ft cord but was typical of the cord later selected for use in the OTSG. The ex-i plosive forming residue was characterized with respect tu elemental chemistry, distribution, and quantity. The characterization consisted of a detailed visu-al examination, metallography, Scanning Electron Microscope (SEM), and Auger Electron Spectrometer ( AES). The results showed that there were no visually observable deposits; however, the SEM revealed two types of deposits: small globules stuck to the surface and a thin unifom layer of residue. The AES showed.the thin uniform layer to be several hundred I thick and composed of primarily carbon with some areas containing detectable amounts of nitrogen, oxygen, and sulfur. The maximum thickness occurred below the insert in the region of the tube 14-24 inches from the top. It was concluded that these de-posits were a combination of explosive by-product and vapor deposited organic material (later identified as polypropylene).
During tube sulfur oxidation removal testing it was noted that the organic film was present even following the sulfur removal testing. Using a Digital 1
Model 10 Fourier transfom infrared spectrometer with a Harrick diffuse re-flectance attachment the film was, characterized as polypropylene. Although not conclusive due to a variance in the H 02 2 concentration these tests indi-cated that this film did not prohibit the sulfur from going into solution.
1 2.9.1.2.
Distribution of Residue l
The earliest cleaning specimens were expanded in short 4-ft lengths of tubing, but they did not show any appreciable amount of residue under Auger analysis.
The short length apparently allowed most expansion residue and debris to blow out either end of the tube, limiting deposition significantly. The results l
may not be representative of actual field conditions, and subsequent tests used full length tubing or other means to contain the debris.
2-62 1
"^
_.._. 2 1._. Z.
i Table 2-1.
Transient Cycles Transient cycles (b)
Tran-Est.
Design actual sient Description (c) cycles cycles No.
1 Heatup 70 to 557F (8% FP) and cooldown, 557 to 240 80 70F 2
Heatup, 532 to 579F (0 to 15% FP) and cooldown, 1,440 770 579 to 532F (15 to 0% FP) 3 Plant loading 48,000 36,000 4
Plant unloading 48,000 36,000 5
Step loading increase 8,000 6,000 6
Step loading decrease 8,000 6,000 7
Step load reduction to auxiliary load 160 120 8
Reactor trip from full power 400 300 l
9 Rapid depressurization 80 40 10 Change of flow 20 10 11 Rod withdrawal accidents 40 35 10 12 Hydrotests 13 Turbine trip ~
~
~
150 100 14 Loss of feedwater flow (a) 80 40 15 Lossofstationpower(a) 40 20 1
16 Steam line failure 1
0 17 Loss of feedwater to one OTSG (dry, depressurized) 20 10 Stuck-open turbine bypass valve (dry, depressurized) 10 5
18 Drop of one control rod 40 19 Loss of feedwater heater 40 20 (8)These transient cycles are a part of the 400 design cycles of transient No. 8. not in addition to them.
(b)All cycles are based on a 40-year design life.
(c)The transient conditions above are provided for equipment design proce-dures and are not intended to be actual transients or operation parameters.
2-70
(
l 7
_.,.f_
i- ~
f~,
, i
-^
i Table 2-7.
Nonnal Operation Total Tube Loads, Mechanical + Thennal l
l Load,(d) 6, in.I") Load Id) l Transient Temp.
AT,(a)
E, n.
i d,in.(b) 6, in.ICI lb l
No.
F F
10 psi 10 '/*F Ib 5
d III 579 509 29.284 7.879 0.100414 2.35610
-670 2.31763
-775 1A i
1B 350 280 30.25 7.63 0.0336 1.63392 649 1.79519 1107 2A 582 512 29.272 7.882 0.103238 2.43278
-498 2.42292
-525
]
28 532 462 29.472 7.832 O.099961 2.31288
-65 2.38819 143 l
3 582 512 29.272 7.882 0.102783 2.45912
-427 2.46202
-419 l
l 4
558.5 488.5 29.366 7.858 0.100186 2.40626
-216 2.44822
-100 72 (a) Temperature increase above 70F.
(b) Negative of rod element deformation loading.
"~
(c) Relative displacement between tubesheets at center.
(d) Tube load = EA([(6 + 6 )/L] - aAT) where A = 0.0663127 in.2 and L = 673.375 in.
d I") Relative displacement between tubesheets at outer tubes.
II) Transient 1A: heatup, 18: cooldown, 2A: power increase, 2B: power decrease, 3: power loading, I
4: power unloading.
i i
t I
l 1
i Table 2-3.
Accident Condition Total Tube Loads, Mechanical + Thermal 4
Load,(d)
Load,(d) i AT I'I E,
a, 6
- I"*(b) 6, in.(c)
Ib 6, in.I")
Accident
- Temp, l
Ib condition F
F 10 psi 10-*/*F d
5 IO 235 165 30.76 7.456 0.168096 1.14863 1408 1.74938 3140 MSLB LOCA
~248 178 30.70E 7.477 0.027093 1.41954 1585 1.78655 2641 3
FWLB 625 555 -
29.05 7.925 0.197079 2.53$06
-620 2.55524
-570 (a) Temperature increase abcve 70F.
(b) Negative of rod element deformation loading.
(c) Relative displacement between tubesheets at center.
(d) Tube load = EA{[(6 + 6 ) / L] - aAT) where A = 0.063127 in.2 and L = 673.375 in.
l t
i d
I 7
I*) Relative displacement between tubesheets at outer tube.
IIIMSLB: main steam line break, LOCA: loss-of-coolant accident, FWLB: fee 6sater line break.
t i
_f i
l I
._.l
.._ )
i 1
'l
l Figure 2-1.
Pullout Load Design Basis
~
70 5
.Il
/
High yield tube 56
/
-4 y
Low yield tube l
~
3140 lbs.7 3 E.
. 42 2
5
~3 m
_i
-2 28 Tube CD = 0.628" Tube thickness = 0.0385' 1
14 g
ra o
i O
0 O
0.2 0.4 0.6 0.8 1.0 1.2 Strain, %
Design basis: 0.16% strain at 3140 lb. Ioad for O.625" OD X O.034" wall tube 2-78
-~--_. -
- e
~
Figure 2-4.
Statistical Margin Detennination - Objectives
~
99% Probability @ 99% Confidence Level n
~
x4 n
4.o
-2 2
x:
E, x- - n x n
(,o n -1 s
X
<ks.
=
=
r er 6
i e
i 2
E
~
a
.I W
I, l
- 3140 Note: K factor for sample
~
Load (Ibf)
'of 30=3.446 9
4
~
m l
2-81 l
Figure 2-12a. Residual Stress Measurements for High Yield Tube (Penn State)
Inconel Tube Ov lay
~
/
i V
T besheet l
/
i
/
Expansion 26 ksi Transition Q
E'1s j l
10 ksi l
A
+-e=~ 4 i
/ l:
/
7 ksi l
lO!.
Residual stresses at 55 ksi tube inner surface, after electro-Polishing.
l l
I 2-90
_.,%-e=
.--m._,,-
_r,--.
.__.._m Figure 2-12b. Residual Stress Measurements for Low Yield Tube (Penn State)
Inconel Tube J
N Weld Clad i
Overlay
'l V
l l
Steel
~~
l l
Tubesheet l
l
/
l Expansion Transition 34 ksi i
ksi f l
1 ks!
l b
l
+-= 15 U
ksi iO; Residual stresses at 40 ksi tube inner surface, after electro-polishing.
Y m.
e b
2-91
--- : =..
I Figure 2-13.
OTSG Ful! Scale Test, Hydrostatic Test Pit at Mt. Vernon i
HAN0 HOLE MANNA
'HOMINAL 12' I 15' j
i WORK PLATFORM N
g 10P VIEW 0F - 0TSG
=
SCAFFOLDING WORK PLATFORM STAGING AREA /
VIDEO DBSERVA 10N l
CATWALK 30' IENT HAN0 HOLE l
~
CA15ALK l I _ SHOP FLOOR LEVEL
,,,,,gt, l
... m..r.,:. g-.7.g
- : :r..
I d
I 4
J i
m
- f!!I! lll:!!i 4 L ga g3e
. s
^
1i
?!#1 !!:!?ti '
ll!
2s' is-untu
. uj.
L
/
M
/
/
if
?"
'zj*a j
.,.. [J.
VENill All0N 2,.
If 8'*"
ELEPHANT
~~
IRUNK 40'
, ~
WORK PLATFORM l
4 g
__ 1 J
l-t
Figure 2-17a. Qualification Program Leak Rate Data, Ten-Tube Test Blocks 400 DESIGN 08]ECTIVE SP1(SEC-PRI)
?
300
~
SP1 (THERMAL L.
4 1.0A0 CYCLED)
A (EXTRA HIT) 200 N
{ E NN
["
A (THERMAL 100 CYCLED)
A(INITI AE) 0 i
i
- 0NLY 9 TUBES IN H 1
BLOCK H WITH 10 TUBES = 1874 x 10 LB/HR BLOCK H EXTENDED TEST @ 682. 5 HR: 464 x 10-6 LB/HR*
t 900 t
/
0 (4009 )
[ H (2500 PSIG)*
800
=
d 700
'e E
s 600 a
\\s b
500
's C
I f
' ~ ~ ~ ~ ~._
400 DESIGN OBJECTIVE j E
300 - f L 0(AMBIENT) 200
=
100 0
1 I
O 10 20 30 40 50 60 70 80 90 100 110 120 Time, nours Note: For average tube leak rate, divide test block leak rate by 10.
2-97
Figure 2-18.
Tube Load Vs Joint Strength During LOCA t'
4596 EXPECTED JOINT STRENGTH
]
3140 O
O MINIMUM JOINT STRENGTH
=
2641 o
/
/
/
/
RAMPS TO A FINAL YALUE OF 2641 LB. @
5 MIN.
TUBE LOAD 0
l I
O 23 300 Time Af ter LOCA initiation (seconas) 2-99
k figure 2-20.
Temperature / Pressure Vs Time Leak Data, 0-52 flours
!t 1700 73 OATA BEGINS AFTER 30 HOURS OF CURING 1600 72 m i
u.
n M
PRESSURE iS O
0.
v v
1500 71 ao m
'3 d-m a
B n?
e
'2 na m
a.
S 1400 70 1
l 1
TEMPERATURE./
69 1300 1200 Lt La.La.1 LLL12.Lu_Lt.LLu.nu_u.1 LLA.Lu LU.LLW.1..W.W 1 e a a ai 68 0
4 8
12 16 20 24 28 32 36 40 44 48 52 HOURS l
l l
i Figure 2-21.
Temperature / Pressure Vs Time Leak Data, 0-60 llours
~
2200 72 l
TEWERATURE I
i 71 l
J 2100 i
70 09 g
ci S
DATA DEGINS AFTER 401100RS OF CURE TIME 68i sa 1900
- PRESSURE g
e,o g
s sa m
67 g l3
{f.
E 4
1800 Fu 66 q.
1" 1700 65 64 1600 63 1
1500 -- L - L__L_.l.J_ _LJ l..l J -._.l.. I I
I I-t i
I L-1 I
L.1__ L _L I
I I
I 62 i
0 4
8 12 16 20 24 28 32 36 40 44 48 52 56 60 LIME (ll0URS)
I
Figure 2-22.
Straight Tube Model With Elastic Racial Displacement
\\N\\\\\\\\NNNNNNNNN Y=3" OOOOOO-511ers, Cases 0&P rree, Cases N & Q l
s 1.0825" Y1
=
Y' = 1.645" l
l i
Transition Lenath h-0.C625"CasesN1&0 0.625" Cases N2, P, & Q E
i i i
ll I
I I
I I
-)
Y = 1. 02 " ---
I 5
0.2785"R x
(Cases N, 0, & P) l y
d i
0.3125"R X - Radial (All Cases) y Axj31 Z - Hoop a
z-x Y=0" 00000O
/////////////////
2-103
Figure 2-23.
Straight Tube With Short Transition and Free End (Case fil),
Tube Stress Distribution - Inside Surface i
i SEE FIGURE 2-25 i
W
- Z 1200 2
2 x - RADIAL y - AXIAL i
800 z - HOOP i
~
ex 400
- i x
1 x
m-0 5
M
-c c
o 5
T ry l
i O
-400 N
m.
m g
s.
-800
-1200
- Y i
1 j
-1000 a
I
.)
- 1. 0 -
- 2. 0 3.0 j
Tune lengtli, inches i
I i
Figure 2-24.
Straight Tube With Short Transition and Free End (Case N1),
Tube Stress Distribution - Outside Surface
~
n
~
2 x - RADIAL I
y - AX1AL o
1200 4
i W
z - HOOP 800
=
n
.Y
)
400 x
~
Txy
. t... A N
O c
=
n 5
i w
ay
?
-400
.,Y G*
u, ry
-800 W
-1200 SEE FIGURE 2-26
-1600 f
i i
i 1.0 2.0 3.0 l
l Tune lengtn, inches I,
t
'l
Figure 2-25.
Expanded Scale Straight Tuna uith S 1ert Tr:nsition anc Free End (Case N1), Tube Stress Distribution - Insida Surfac X - RADI AL y.A7,lAL vz z - HOOP 1200
&---c 800 s
ex s
/ \\
Txy 400 N
K
+
0 e
m ~% j e.
V, 400
=
800
-1200
-1600 O.90 0.95 1.0 1.-05 1.10 1.15 Tuoe Lengtn, incnes 2 -106
.,... _ _ _. ~-
e c
G i
60 nn La. U qI m
os CL m3 d,i m
c o0 g u.-
MM o
cc a
mC w a L
W 8
- < g cs o
4 x o Y$
E
- Z l
o-A ea j
^ C n m N 2-ea %
Ln o.
un
-u m
3.m.=
=
Co oc C
4 aw
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=
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2-107
i 4
I Figure 2-27.
Straight Tube With Long Transition and Free End (Case N2),
Tube Stress Distribution - Inside Surface rz x - RADIAL 1200 2 3
z - Ho0e 80, fx 400 r
i
'F.
~
rg '
0 S
=
m' TXY j.
0
-400
}
i m
-800 G
i 4
co
-1200 l
-1600 t
I l
1.0 2.0 3.0 l
l 1
Tune Lengtn, incnes i
i l'
i l
1 1
I figure 2-28.
Straight Tube With Long Transition and Free End (Case N2).
i Tube Stress Distribution - Outside Surface 1600 x - RADIAL
- Z y - AXIAL 1200
_c Z - HOOP 800 ex 400 r v
<-xg
~
TIf A
5 0
e i
i e
g 4 ~ _r i
u ry 7'
-400 E3 i
m
-800
-1200 i
i i
1.0 2.0 3,9 Tune lengtn, incnes i
rigure 2-29.
Straight Tube With Short Transition and End Rol,lers (Case 0),
Tube Stress Distribution - Inside Surface SEE flGURE 2-31 l
'i
- rz m
1200 N
x - RADIAL 800 c.
y - AXIAL l
z - HOOP ox j
2 400 a
9
'a vy s
a 0
V-0 3
Ixy i
- i S
j 7
g -400 5
1.
-800 ii j
-1200
-1000 I
l g
1.0 2.0 3.0 Tune Lengtn. incnes t
I
Figure 2-30.
Straight Tube With Short Transition and End Rollers (Case 0),
l i
Tube Stress Distribution - Outside Surface j
i 1
i i
i 1600 l
- Z t
1200 c
x - RADIAL i
4 y - AXIAL 800 z - HOOP i
ex 400
^
j c
'Y I
0
=
e-a 3
.. TX i a
a n
~
.L
-400 l
a l.
i t
-800 W
'i
~
SEE FIGURE 2-32 f
-1200
-1600 l
{
2 i
i l
1.0 2.0 3.0 i
Tune Length, incnes l
l ll
Figure 2-31.
Expanded Scale Straight Tube With Short Transition and End Rollers (Case 0), Tube Stress Distribution - Inside Surface x - RADIAL l
y - AXIAL Z ~ HOOP l
~
d' Z we
- 2 800 trx 400
- w x
~
0 Try *
~
~
/
M0,W j
.4 g
E 400 Txt G
-800 E
vy
-1200 l.
4 8
e i
i
-1600 0.90 0.95 1.0 1.05 1.10 1.15 Tune Lengtn, incnes i
i m
h l
i
'\\
~
Figure 2-32.
Expanded Scale Straight Tube With Short Transition and End Rollers l
(Case 0), Tube Stress Distribution - Outside Surface 2000 x - RA0lAL y - AXl AL I
l600 z - HOOP 1200
- 2 C
~
~
800 cx ye M
Try Mo 0
-400 TIV
';3 gy
. ' ~ '
-800 i
i A
i w
i
- 0. 00 0.95 1.0 1.05 1.10 1.15 Tune lengtn. incnes
(
i I
I i
i
4 Figure 2-33.
Straight Tube With 1.ong Transition and End Rollers (Case P),
Tube Stress Distribution - Inside Surface i
I
- Z
~
{
N, e
1200 x - RADIAL y - AXIAL I
z - HOOP 800 1
u
=
ex r,
(-
y 400 C
~
- y
\\
=
= "
k a
}
4::
0 2
I 200 i
1.0 2.0 3.0 Tune lengtn, inches t
i i
i
d 4
Figure 2-34.
Straight Tube With Long Transition and End Rollers (Case P),
Tube Stress Distribution - Outside Surface l
i m
1200 :
c c
x - RADIAL y - AX1AL r - HOOP i
800 E
i i
f cx
-x--- _ x_/k 5
400 i x-X Y
3r 1
2 c
- ^ ;
0 =
=
=
-200 s
1.0 2.0 Tune Lengtn, inches 1
l I
l
Figure 2-35.
Straight lleavy Wall Tube With Long Trt.nsition and Free End i
(Case Q), Tube Stress Distribution - Inside Surface l
l
~
I rz 1200 x. RADIAL y - AX1AL 800 z. HOOP
- X 400 q
Nu ay 4
sa e
0
=
.4 LXY g
E
-400 7
-800
(
-1200 i
-1000
_i 1
e 1.0 2.0 3.0 Tilne Lengtn, incnes t
i i
i
}
I I
i
'I Figure 2-36.
Straight !! cavy Wall Tube With Long Transition and Free End (Case Q), Tube Stress Distribution - Outside Surface
~
1600 1200 x - RADIAL y - AXlAL 800 z - HOOP a
(Z
- l i'
9 a
400 o
Q Y
m x% w~-
=
j u
.a0
?
i
=
800 N
l
-1200 I
i
~
l
.l t
i I.0 2.0 3.0 Tune Lengtn, incnes l
i l
1 t
4 l
I I
t i
Figure 2-37.
Plastically Defoniied Tube Model With Interfacial Pressure Load and Free End j
Case R Case S Y=3"-
y 3n_
0.3125R 0.2785R j
0.3125R Y = 1.64 5-
~ 0.2785R-~
l Y=1 0825
\\ \\ \\ \\ \\ \\
?
Y=i.02-m Y=1.02 G
(
~
A=0.01" <-
E A=0.01"
+
i P=3350 psi P=3350 psi
?
I e
Y
-0.2885R -
.X - Radial 0.2885R Y - Axial i
=0.3225R 0.3225R Z - lloop
~
- -X
{
f Z
+
Y*0" fff@yl)y
~
noooao i?
/////////////
I
- 1 ii l
Figure 2-38.
Plastically Ceformed Tube Model With Interfacial Pressure Load and End Rollers Case U
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
Y=3" 1
0.3125R' N
0.2785R Y =1.~082 5 I
Y=1.02 1
c.=0.01 P=3350 psi 1
0.2885R y
i 0.3225R X - Racial Y - Axiai Z - E00p 7X Y=0" noooor)
/
~
\\\\ \\ \\\\\\\\ \\\\ \\\\ \\' \\\\\\
I' 2-119
1 F10ure 2-39.
Deformed Tube With Short Transition and Free End (Case R),
Stress Distribution - Inside Tube Surface
)
SCALE EXPANDED i-10000 F
i 5000
- Y 7,y i
\\_~
m 0
e___9 7,
g__-
w:
g FX l
-5000 E
I
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.15000 0
y - AXIAL i
i a
-20000 z - HOOP Y
M
-25000 d'Z
-30000 c'
-35000 0
0.5 0.90 1.00 1.04 1.08 1.15 1.5 3.0 Tune lengtn. incues
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- v..
Figure 2-46d. Tip of Large Crack in Strip 1A of Tube Sample ARC-30 (460X) h. g J 0 1 ~ 2-132 \\ l Figure 2-46e. Crack Tip Area in Strip 1A of Tube Samce ARC-30 (la00X) . _, f. - $.f kyY.L 4:. Anks,Q{d6%lG;Zb 'l' l:) M4 g- .'[ ] i - Gi<-y r .? N$57 ;. MR . W.7. 4 C. n .'j ~^ T.a.s~.s.m,.c,z 4%.%. x d . x. e -,Y ~$ : e s,%. ' e e.- .;*~~
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' "h_ _' _. N % OO c - i.;a n. i l Figure 2-46f. 100% Through-Wall Circumferential Crack After Coating. Sample B-1 from Tube A78-32 s i, ~ i; ,, W 'i wi- ^I rme ; \\ i \\ ~ ,-e# ~ I i 1 1 l i' i l, t Figure 2-47. Obrigheim Steam Generator Tube, As-Built Too of Tubesheet Nominal 00 7/8" // / /l / % axial Cracking te (Primary Side) HR #3 /: ![/ [ 2.95" $y/ _ Axial and Circumferential q Cracking (Primary Side) A+ / a yi 'e+ r ff u' '
- f<egion with
't Tuce Sheet Hole 10 Blisters in* 6 / Min b $nrolledTueeCD Min t 34p (Diametrical) ,] f 1111 Illl 9 u/ [ Axial Cracking l HR #2 l/ (Primary side) A I i 2.95" l' /ll l Axial and Circumferential l l Cracking (Primary Sice) A^ w.+iT;/ unreitee Tuee 4411 rnickness 4.8" /j /s-CDf~ .ax g.u - unrened Tuee ::
- yn
/,pa 'p,.1yl 1 [ nis Roll A:: ears Clear :f Cracking 7g u? h 2.9s- /a* =, ,41 // :nc3Pel Clac - ~.,, 2-135 .. o Figure 2-47a. Comparison of Rockwell Hardness Rockweli "C" Effective Range 70-20 70 60 - Tube Region Testad Unexpanded Transition impandac gg _ 40 - Rockwell "S-Effective Range 100-0 30 105l-- . l -\\ s\\\\\\AA\\\\\\ ID ID 100 CD \\ t 20 - OD ODI'O 0o\\\\%%\\'3D l 10 ' 90 MA i \\ Ys l 10 l 80 70 MM 0-l i l l I 2-126 e .-w. . -.. - -. ~ ~ w Figure 2-47B. Unexpanded Portion of Tubes 100X 0xalic Etch OD e 2;-ww=y-n~xm.ex tm n.sacz!. *2'Mr.E_%J w_':?14 == _, ^ .O..?,.,.~.; ".' '.Y.~.1.-}.: s;.,.;.&.,,a'W,...;;i.%.'.,. '.!{.Rs. h g..{G[.,f..'r: ji,2.
- l Js * *.
............t.. L. . s
- m...
.? -?..,, -:...,.... 7...,y,... v... '. :- '. 3.~. ;.... > ;, j., *,..,, 3 . ~.,.. '.. f f*.....,.,.,; . :z..~W::... Q..-y. e..'.'[..' y. .s. ^ '.....
- 2...'n
. r,,
- l.
' g,. *. .r .,:= c .... 1. .t. .s .'.8. m. v. S. 3..: .c, ...,.~,,.. -6 9- ,..m :. 4, y ..s ', l .... v','. :. ...s.............t.,,.... ;[,-....... ..- = ;.;.. - L.. '. &... m.$,...,5.N. R...O'.5 W.,.. ~. ..,...~v.. l. ,...... l - f..., l.5. ~.1 . z .., ~ - w_ J }~W M
- AU2 L % & $$.$ ~] E E Y_ q' k N E 5 ?" Y E S M M %
2 ID I 4 i / % 7-f ( . 1 N/ Unexpanded 2-137 \\ l I 1 Figure 2-47c. Roller Expanded Tube Away From Transition Area 100X 0xalic Etch Z .s. .. -.,% m.. ,, A w 2.....:m .%...;...<.......,.8 ..a%....'m.4 C.E ~M:.";'.1,,yL.... &. W... .: G. :: ?. d:. K ?.# ?.- i.t. :t...; 3 x. f.....e..:, :. ' ~. . a :-~ - .r..- . z.,.; -
- a...
r. .v. ~..,u. w. .w i.;L.. .n...**
- .5..
.g.'
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- y..:.. ;: s.:
.. )....c......,.y,.. z w... ...,.,..m . r,.. . a. s..,. s,. ~,.. u...s.',.e,...:..,~;...~.~. ,.a
- +,:..~.
.y-._... r. . t r-. ..:......... 3 ; :. ~. N.g.. s.% Yb$.,...,.....!.%N.'1.YV.,.'b,.Y. ?.. <.'.'... .. r ....o.. n
- t".';
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- 4.. -
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- iy %u
- :.>. : n :. :
~. -,..... .u .: n.:s w...s... ._f....s -.... r. ..m..,:.,..,,... ~. ..r .. -.m......a,. ..m Lt. w-wwwww%.m.a;.:.nes %. .- M 10 Figure 2-47d. Kinetically Expanded Tube Away From Transition Area 100X 0xalic Etch .a.~ ...,g . r w,s x,.. :..~.. 1...w,.. m...,../..,... .m:
- 2...:....
s. ..,.w. '.'~.W.,....... ' ' ' '.. e.. 4,....... '".[.,':'. 5 ;j,.u.i. ~ f,,.w r .y ..c... ~ > . c. s .g ... ~.. z.. *..: u. , ~.... -. <t ..s. >.1, . c:.'g:.a.y.:.. ~ ~ .e ...-v.,,.. ....a ...2., .... c... t,.~ Q... 5., .,...... r.' .?., U '.... .,. W. ~ ~. -. s. 2.f. .v: ..G..: .c... i,. ~< .s l w.?.'m.* l * :...,.,,. d.'.....,,-n.. 3 '.- .s e . s> n. d
- a..q v
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~v.. q ?.'".M.',.-*.* O. *CMDM.~,'. p .. g. og i. q i,8.. c.* -- ?... i..,.- lg.',., '[,.. '.J1"...".' 'M.. a @4 nJ,...,.?. Y rN .p . r, i - r -f u... t ....~x.-. 3 t% ./ 2-138 =. =___:__=_=_=-. - Figure 2-47e. Roller Expanded Tube Transition Zone (100X 0xalic Etch) cc ^.,... _ 2 4 e c . ~... = e,..,.; ... : ;;- c.d.->. :. : a : ..v... .n.
- w.n.~... -my '.. +..M: '.. u.-
- s W+
- t..w.,.,.. >
- ..: :
.t* a._ ~ .nu. w... ;... -.. 7 m ix.-= n g w n...5 2._ w.n Figure 2-47f. Kinetically Expanded Tube Transition Zone (100X 0xalic Etch)
- D
.e-...- -. a.. a.- % g e l a +. 1 -s -s 5 2 5 5 g 5
- 6.. ~._:
I s.... ...t, t s ..,Wh '4WWe l ..' :. -w h. ( s wdd., ob r 'N F' I f t 7 ./ f3nSition e 2-139 Figure 2 48. Multi-Tube Block Specimen 3 CENTRAL TUBES e NlN N m TEST BLOCK i I [ lll l l1 .I l l 3 I I 1 I [ l !l l ll l l il i I i l l' l' I l I l I Il ll I l i i I i i 11 i li I 1 i si i il i ti ii 1 g/ 9 SURROUNDING TUBES / 9,V E 4 / E i E ( E E E E \\ E I 3 CENTRAL TUBES O ROLL PLUG INSTALLED BY WESTINGHOUSE TWO SEQUENTIAL EXPLOSIVE EXPANSIONS BY B&W/ FOSTER WHEELER 2-140 -~---4-.----a.- ...._...- ~~~ - -. -~ - - -.....- ~ ~. - - - 3.2.1. Loading on OTSG Tubes A detailed definition of loads is given in reference 9 and can be summarized as primary-to-secondary differential pressure loading for nornal operation (1245 psi) and steam line break (producing the highest t.P design loading, 2500 psi), secondary-to-primary differential oressure loading due to LOCA (1050 psi t.P), and tensile loading on tubes due to cooldan transients (the MSLS tran-sient producing the highest axial load). 3.2.2. Test Methods Test methods include the' following: 1. The bubble test, where the primary side is drained to a few inches above the upper tubesheet and the secondary side water level is lowered and pressurized to 150 psig (see Figure 3-1). Kinetic tube expansions and upper tubesheet plugs are leak-tested by visually observing gas bubbles in the upper head. Comparison of soap bubble tests with water leak tests (section 2.6.3.1) indicates the bubble test has a lower limit of detect-ability which is less than the 3.2x10-6 lb/hr per tube limit. 2. The drip test, where the primary side is drained completely, the secondary side is pressurized to 150 psig, and water leakage from the tune ends is observed in the lower head. This method leak tests plugs installed in the lower tubesheet and the tubing expansions. 3. Operational leak test, which establishes primary and secondary pressure at about the normal operating levels, but with a primary-to-secondary 2P exceeding the normal operating value, primary temcerature is naintained by pump heat, primary-to-secondary leakage is monitored by measurement of tritium concentration in the OTSG seconoary. The limit for naximum allow-able primary-to-secondary leakage in normal operation is 1.0 gen (Techni-cal Specifications). 3.2.3. Backuo Reoair Method Bubble leak testing of the steam generators may indicate the need for a repair method to seal tubes which exhibit greater leak rates than exoected. A mechan-ical roll expansion has been selected as the backup repair method. The roll expansion would be centered about 'l-inch above the 6-incn qualification lergth of the kinetic expansion and aim at 6 to 10". tube wall thinning, using a 3-3 lubricant for the roll expanders. During the qualification process, tubes would be monitored for plastic buckling or strain, which may affect the qual-ification length. The roll expansion would only be used in individual tubes ~ in need of additional' sealing. 3.3. Hot Precritical Testino Following repair of the OTSG's, special testing and monitoring will be per-formed to prove the operational capabilities of the steam generators as de-scribed in GPUNC Topical Report 008, " Assessment of TMI-1 Plant Safety for Return to Service After Steam Generator Repair" (reference 37). f 34 Figure 3-1. OT5G Bubble Test PAN AND TILT VICEO COERA i STANDI.NG 'liAER CVER TUSESHEET SUP. FACE CN PRIt%RY SICE -1 b m,,;;. Cr. a, w. I lll ll'4l,I'I e .? ,,..,m s I.) :.N,5i'. a..'[.,.U.';D..N ' ';*/', 4 W 3 7 . :.., t.,., ;a 9 t.1 - e i t, e.v:< 2 - as.,& r-lhjf8$$jh+h.y, . - 4',.:n :.. - v p v
- ,.....~..
'U ,7 ' '. i Ll hliNbibn [2 N N f...M., N - N , 0 = r.st +.., v 3,3.. 6, '\\ try. ! c ~ q*7 .. o :.8./, Yo 7-h, h.i...D.. 1USE ' k. ' ~ :T ./. L.-O 5- -r.~ j g o. NJ . t f UPPER TUEESHEET .5
- i. :W t...'.~..
K k.:l:ii 'E 't.f. N N l SECCNCARY TO PRIMARY \\ f*..: LEAK PATH j 1 S
- nl p
/i p N2 (~ 150 PSI ~ '.I ,' * :,3*.. y.. . = g.e l . :7-.' ' ~y i',. ..: T*'L '_ q -~ l r . c.. ;.. SECCNCARY SICE WATER we. %Ij LEVEL BELCW UPPER T.S. l I I I a-o l E 4. PERSONNEL SAFETY The safety aspects of ventilation, noise, and handling of explosives are dis-cussed in this section. 4.1. Ventilation Personnel working in the OTSG upper head will wear respiratory equipment. Ai r-borne activity will be limited to that area by a ventilation system drawing air from the upper head through HEPA filters and exhausting it in'the contain-ment. All expansions will be done with the OTSG manway covered. Tests have been conducted on a full-scale OTSG to verify that the ventilation system will be able to accommodate the pressure pulse from the explosion. Further tests have shown that gases from the explosive process are dissipated within 2-3 min-utes, allowing the manway to be reopened with no effect on the containment en-vi ronment. 4.2. Noise Noise level readings were taken during 36, 80, and 132 simultaneous detona-tions in the full-scale steam generator at B&W's Mt. Vernon, Indiana, works. These readings were taken outside the generator at acout the mid-point of its vertical height ar:d an estimated 30 feet from the vertical centerline. The upper and lower heads were in place, and the lower head cold leg openings were covered with plywood. A gap of about 1 inch existed between the steam genera-tor shell and the lower head. Maximum readings of 90 to 95 decibels were obtained. No significant differ-ence in decibel level was noted among the 36, 80, and 132 shots. The noise appeared to travel down through the generator and out the openings in the bottom head and then resounded upward from the pit below. On the basis of these tests, it is judged that noise during the TMI-1 steam generator repair will be at acceptable levels. An added conservatisa for the 4-1 After the charges are placed in the generator, the ordnance cord ends are brought outside the generator, and the manway covers are replaced, all person-nel will be removed from the immediate vicinity of the genieratcr. The li-censed blaster will collect the ordnance cords into a single bundle. The blaster will then check for stray electrical currents using a blasting galva-nometer. If all it clear, he will connect the detonator to the ordnance cord bundle ends and place the cap and cord ends into a cap surpressant box. The blaster will then move to his firing station, check to assure all personnel are removed from the generator, sound the alam, and detonate the charges. After firing, the blaster will witness a TV scan of the fired inserts and as-certain if there were misfires. The presence of misfired charges causes no personnel safety concern since this explosive will not " hang fire" and self-detonate later. It is important, however, to know the location of misfires so the affected tubes will not be missed in the repair process (section 2.3.5.7). Misfired inserts will be removed by the junpers and placed in a storage recep-tacle for later disposition. 4-2 7. o 5. QUALITY ASSURANCE The quality assurance (QA) on this project is specified by GPUN 9 The QA re-quirements of reference 9 are met via confomance to B&W QA Manual 19A requirements are placed on B&W ARC and Foster Wheeler Energy Applicatio QA Inc. (FWEA) by B&W procurement documentation. QA requirements flow to FWEA subcontractors through these same procurement requirements. Conformance to requirements is verified by QA audit, and vendor surveillance by NPGD and/or FWEA. , GPUN, The GPUNC MOD /0PS QA program will govern the site work. The folicwing sec-tions cover in detail this flow of QA requirements. 5.1. Qualification Program Reference 9 defines the overall QA requirements for the OTSG tube rep ject. These requirements are met by conformance to B&W QA manual 19AN.1.2 Equipment specification 03-1134285-0024 is the highest level B&W document that implements both 19AN.1 and reference 9 (and reference 25 is the highes document that controls QA on the qualification program). All subsequent quali-fication program QA requirements are imposed by reference 25. The kinetic expansion qualification program was accomplished by work a ARC and by FWEA and its subcontractors. QA requirements were imposed on these NPGD subcontractors via procurement documents. Work at the ARC was performed after issuance of a procurement authorizati (PA). Technical requirements were specified by an Applicable Documents List on I (ADL), which listed all appropriate technical requirements including QA re-quirements through references 25 and 27. The ARC implemented this QA via QA plans S2011, 82012, and 82013, which have been approved by NPGD. The ARC QA program is approved by GPUN review and by NPGD audit, the latest of which wa December 1981. 5-1 i - ~ _ - -,. _ + -*h m. n-e-- g Work at FWEA was performed by authority of purchase orders. CA requirements are imposed on FWEA by reference 26. FWEA was audited by B&W on May 12 and 13, 1982, and approved. FWEA submitted the procedure required by reference 28 and B&W approved these procedures; references 29 through 34 are typical. The requirements placed on the purchases frca subcontractors by FWEA are stated in reference 26. Conformance to these requirements was verified by GPUN and B&W via audit and surveillance of FWEA (surveillance of FWEA is specified in refer-ence 35). FWEA verified conformance by its subcontractors through audit. 5.2. Manufacturing Reference 36 is the highest tier document dedicated solely to the manuf actur-ing process for explosive expansion devices. It is subordinate to references 9, 23, and 24. Reference 36 is imposed on FWEA; it imposes reference 26 and other QA requirements. FWEA implements the QA requirements of reference 36 through its QA program. Conformanca is assured by audit and surveillance of FWEA by B&W. Specifica-tion and procedures are submitted to GPUN by FWEA for review and approval. GPUN also reviews and coordinates witness hold points through submittal of a QA Surveillance Plan by FWEA. B&W reviewed and approved QA data packages for *he devices before their use. 5.3. In-Process General Reouirements GPUNC M00/0PS QA personnel provide inspection and monitoring of all activities related to kinetic expansion. The results of all inspections, examinations, and testing activities shall be documented. Babcock & Wilcox and Foster Wheeler work activities are described in GPUNC ap-proved procedures, which identify the specific objectives, acceptance crite. ria, prerequisities, data calculation points, and precedural steps. GPUNC indicates any witness / hold points on each individual procedure and/or on the data sheets. 5.3.1. Verification of Pre-Process Recuirements GPUN QC verifies the records of the tamperatures of the tubesheet and the ni-trogen gas. Additional monitoring of the cover gas flow and dew point will also be verified. 5-2 --we ,~w M6 __ __ g 6. RADIOLOGICAL SAFETY The technical development cf the kinetic expansion program was closely moni-tored by both B&W and the TMI-1 Radiological Engineering personnel to ensure that potential field implementation techniques were consistant with T'il-l's as low as reasonably achieveable (ALARA) goals. These goals are being achieved by evaluating the proposed work processed, dress rehearsal testing, and apply-ing remote tooling techniques. Additionally, all previously proven techniques of exposure control such as remote video camera systems are again employed to the maximum extent possible to keep exposures ALARA. 6.1. ALARA Evaluation of Imple-mentation Process Several aspects of the kinetics expansion process presented unqiue problems in the accomplishment of adequata radiological controls. The solution to many of the practical problems of field implementation came through dress rehearsal training conducted in a steam generator located at B&W's Mt. Vernon, Indiana, facilities. Work in these facilities aided the evaluation cf several specific items of radiological engineering concern. These major subtasks were: 1. Expansion device installction techniques. 2. Tube precoating techniques. 3. Airborne contamination potential. 4. Temporary shield usage. In each area, ALARA review of the procedures and methods to be used for task implementation enabled the optimum technique for task performance consistent with ALARA goals to be established. 6.1.1. Expansion Device Installation Technicue The original installation technique entailed the manual installation of each expansion device in the tubesheet. The exposure crojected for the performance of this task was unacceptably high, resulting in intensive evaluation of other 6-1 installation techniques. Using dress rehearsal training, a tool was developed to speed installation of the expansion devices resulting in a projected sav-ings of more than 70 man-ren. Also identified during testing was the need to develop a reliable, low expo-sure method of retreiving the expended expansion devices frc:n the steam gen-erator tubesheet. The method developed (using high-pressure air to force det-onated candles out of the tubesheet) accomplishes this task in the most expe-ditious manner possible, holding man-rem exposures to a minimum. The last portion of expansion device installation of major concern was actual personnel logistics. The planning and studying of dress rehearsal training enabled the development of the optimum locations for each job function. This evaluation will enable conpletion of the task using the minimum amount of people located in the lowest radiation areas possible. 6.1.2. Tube Precoating Techniques (Proprietary) The recognition of the technical requirement to precoat the tubes with a pro-tective substance prior to expansion created a potentially costly evolution in terms of radiation exposure. However, the man-rems avoided by the simplified cleanup operations far exceed the exposure incurred in precoating operations. Several methods of precoat application were studied and the remote method of " bubbling" the precoat up through the tubes using forced air was chosen This i technique has been successfully tested at B&W's Mt. Vernon facility, and its field implementation will save approximately 90 man-rem of exposure over other manual application methods considered. 6.1.3. Airborne Contamination Potential The potential for airborne contamination as a result of expansion device deto-nation wa's of primary radiological controls :oncern. The method developed for airborne contamination control requires the upper steam cenerator manway open-ing to be sealed during detonations and a ventilation blower to take a contin-uous suction on the hand hole opening of the upper head. The blower would exhaust through a high efficiency (HEPA) filter to containnent at:nosphere. A system of the same design as the one to be used inside the THI-1 containment was successfully tested at Mt. Vernon during actual device detonations. Venti-lation system perfonnance was unaffected by the detonation and the upper steam generator head was cleared of gas, etc., within 5 minutes of expansion device 6-2 W,e%.,- % - ew - 4 = - % e y.-,.-e = _. _ _. detonation. The manway cover employed effectively contained debris and partic-ulate matter inside the generator. These test results indicated the ability of the proposed ventiatlion system to adequately contain any airborne contami-nation produced by the expansion device detonations. Calculations based on an extrapolation of airborne activity data taken during explosive plug ooerations indicate that airborne contaminatir levels inside the steam generator head will be well within the limits set for workers equipped with respiratory protection apparatus. 6.1.4. Temcorary Shielding The use of temporary shielding to reduce radiation levels in the steam gen-erator upper heads is an important concept to reach TMI-l's ALARA goals. The continued use of shielding during the kinetic expansion process was evaluated and a shielding scheme for the upper tubesheet was developed consistent with the expansion device installation. Testing at Mt. Vernon has indicated that the detonation of expansion devices does not damage the temcorary shielding material. Testing has also indicated that while covering a large portion of the tubesheet with shielding will cause a relatively high ressure pulse in the steam generator head during detonation, this does not impact on ventila-tion system survivability or the ability to control airborne contamination. The use of temporary shielding is expected to save approximately 40-60 man-rem. 6.2. Training Training for the implementation of the expansion program is extremely impor-tant to meeting the goals of the ALARA program. performing certain manual tasks in the steam generator head area is a necessary and unavoidable part of kinetic expansion field implementat-ion. To keep exposures associated with in-head tasks ALARA, the workers engaged in the task must be as preficient as possible in performance. To achieve a hign level of proficiency, full dress mockup training will be =rfonned by all personnel scheduled to do in-head work. This training will be done on mockups that simulate as closely as pos-sible the conditions that will be encountered in the actual work area. The training will be conducted by experienced, qualified instructors ard will be periodically evaluated in its effectiveness by suoervisory personnel. Train-ing of this nature has been successfully imolemented for other tasks and is considered an integral part of the ALARA program. 6-3 6.3. Open Items In estimating the impact of cleanup on total job exposure, the worst case of extended manual claanup inside the steam generator heads has been assumed, and the subsequent exposure estimated for this task is high (110 man-rem). The process to be used for final cleanup will be re-defined, with particular at-tention paid to ALARA concerns, when the scope of the final cleanup effort has been established. 6.4. Summary Attention has been focused on ALARA concerns throughout the entire development of the kinetic expansion program. As the needs of the program have been de-fined, modified, or expanded, new approaches to keeping exposure ALARA have been appraised and applied to the method for field implementation. The effort applied to the ALARA program for kinetic expansion has resulted in the develep-ment of a field installation approach estimated to keep total job exposure below 500 man-rem. 6-4 -~_- a -. - +.. ~,.. ~. REFERENCES 1 GPUN TMI-1 Special Temporary Procedure, " Steam Generator Upper Tubesheet Flush" (Craf t), May 21, 1982; GPUN CRF 915, June S, 1932. 2 GPUN TMI-1 Special Temporary Procedure, " Crevice Vacuum Flush" (Draf t), July 2, 1982. 3 J.G. Reed (GPUN), Inter-0ffice Memorandum f;o. JGR 82-0044, " Chemistry Summary Report - July 1982," August 18, 1982. 4 GPUN Specification No. SP-1101-12-038, "TMI-1 OTSG Tube Plugging Cri-teria," Scheduled for Release September 24, 1982. 5 B&W Document No. 08-1119318-00, "Specificatioh for Steam Generator Repair Hardware." 6 B&W Cocument No. 08-1001892-05, "Specificatior' for Steam Generator Tube Stabilizer." 7 T. M. Moran (GPUN), Inter-0ffice Memorandum No. PA-756, "TMI-1 OTSG Repair - Craft Assessment of Plant Safety for Operation," August 24, 1982. 8 B. D. Elam (GPUN), Inter-0ffice Memorandum No. MC-1319, TDR-367 (Draf t), August 16, 1982. 9 GPUN Specification No. SP-1101-22-006, Rev. 4., 10 Static Strain Analysis of TMI-2 OTSG Tubes,- NP-2146, Electric Power Re-search Institute, Decemoer 1981. 11 ASME Boiler and Pressure Vessel Code.1980 Ed.,Section XI. 12 THI-1 Steam Generator Tube Rolled Plug Cualification Test Report, WCAP-10084, Westinghouse Electric Corp., April 1982. 13 GPUN Engineering Mechanics Memo No. EM-82-156, " Evaluation of TMI-1 OTSG Tube and Tubesheets," May 4, 1982. 14 TMI-1 OTSG Failure Analysis Report. TDR-341, GPUN, July 1982. 15 OTSG Reoair Safety Evaluation, GPUN, Subitted to NRC August 19, 1962. 16 S. Yokell, " Heat Exchanger Tube-to-Tubesheet Connections," Chemical Engi-neering.~ Yol 89, No. 3 February 8,1982. A-3 l .. a 4 c.. w..-..--.,%m-emn. 4 17 N. M. Cole and R. F. Wilson, MPR Trip Report, " Report of Peeting With Kerncentrate Doel on Tube Cracking Problems in the Roll Transition Area of the Steam Generators at Doel 2," March 8,1982. 18 D. G. Slear (GPUN), Inter-Office Memorandum No. TMI-1/E3706, "Doel Unit 2 Steam Generator Tube Leaks," March 2, 1982. 19 A. Nadai, " Theory of the Expanding of Boiler and Condenser Tube Joints Through Rolling," ASME Transactions, November 1943, p. 865. 20 GPUN Specification No. SP-1101-12-036, Rev. O, " Test Requirements, Explo-sive Tube Expansion Impact on Installed Roll Plugs," July 30, 1982. 21
- 1. Berman and J. W. Schroeder, Near-Contact Exolosive Formina, Foster Wheeler Development Corp., Livingston, New Jersey.
22 GPUN Specification No. SP-1101-22-008. 23 Babcock & Wilcox NPGD Quality Assurance Manual,19AN.1, Babcock & Wilcox. 24 B&W Equipment Specification No. 08-1134285, " Steam Generator Tubing Expan-sion Qualification and Field Repair." 25 B&W Specification No. 51-1135113, " Explosive Expansion Qualification Re-quirements for Mechanical Testing for Explosive Expansion Repair of TMI-1 OTSGs." 25 B&W Specification No. 09-1212-01, " Quality Assurance Program Re.quirements for Nuclear Equipment," January 16, 1974. 27 B&W Specification No. 09-1427-00, " Quality Assurance Requirements for Research Programs." 28 B&W Occument Nos. 48-l'20199 and 48-1120209, " Quality Requirements Ma- . trix." 29 FWEA Procedure No. 5054-QT-1, "Xinetic Expansion General Requirements." 30 FWEA Procedure No. 5054-QT-2, " Tube Tensile Tests." 31 FWEA Procedure No. 5054-QT-3, " Kinetic Expansion of Tubes in Test Blocks." 32 FWEA Procedure No. 5054-QT-4, " Kinetic Expansion Proof Load Tests." 33 FWEA Procedure No. 5054-QT-5, " Kinetic Expansion Thermal Cycle Cordi-ti oni ng." 34 FWEA Procedure No. 5054-QP-1, " Kinetic Tube Expansion for TMI-1 Steam Generator Repair." 35 B&W QA Surveillance Requirements for TMI-1 Steam Generator Repair Qualifi-cation Program for Kinetic Tube Expansion at Foster Wheeler Development Corp., Rev. 3, September 3,1982. i l A-2 i ~ s, - 36 B&W Specification No'. 27-1134835, " Manufacturing Soecification for Qualifi-cation and Site. Explosive Expansion Devices." 37 GPUNC Topical Report 000, "Assesseent of TM1.1 Plant Safety for Return to Service After Steam Generator Repair." 38 GPUN Specification No. SP-1101-12-030, "0TIG Tube Plugging With B&W Welded Caps and Stabilizers." 39 Nuclear Safety / Environmental Imoact Evaluation fcr OTSG Tube Plugging _Using S&W Welceo Cao Witn Stan11izer. 40 GPUN Specification No. SP-1101-12-029, "0TSG Tube P'ugging, Phase I." 41 Report on Prequalification Charge Sizing for TM!-1 Steam Generator Tube Expansion, 9-69-5049, Foster Wheeler Develcpment Cor;.., July 19, 1982. 42 TMI-1 Prequalification Charse Sizing - Status. Report on 20/14-6 Expansion, Fostar Wheeler Developmant Corp., July 8,1982. 43 ASME Boiler and Pressure Vessel Code.1965 Ed., Section ITI, Summar 1967 Adcenda. 44 Specification for Steam Generator, B&W Contract No. 620-0005 for Metro-politan Edison Co., Three Miie Island (TMI-1), CS3-33/NSS5, April 1971. 45 Regulatory Guide 8.8. Rev. 3, U.S. Nuclear Regulatory Cornmission, June 1978. e 46 TMI-1 Final Safety Analysis Report, Docket No. 50-189, Oper. License No. DPR-50. i 47 Deter nination of Minimum Required Tube Wall lhickness for 177-FA Once-Through Steam Generators, BAW-10146, Babcock & Wilccx, October 1980. 48 GPUN Specification No. SP-1101-22-009, "0TSG Kinetic Tube Expansion Process, Monitoring, and Inspectico " 49 J. N. Goodier and G. J. Schoessow, "The Holding Power cf Hydraulic Tight-ness of Expanded Tube Joint: Analysis of the Stress and Deformation," ASME Transactic_n_s,. July 1943. 50 E. D. Grimison and G.- H. Lee, " Experimental Investigation of Tube Exaan-sion," ASME' Transactions, July 1943. 51 H. J. Connors. " Fluid-Elastic! Vibration of Tube Arrays Excited by Cross-flow," Presented at the ASPE Winter Annual Meeting, Cecember 1r 1970. (Paper sponsored by the Heat Transfer Division of the ASME.) 52 EPRI Report NP-lE76, Electric Power Reserc Institute. Palo Alto, Cali-fornia (1981). A-3 r , -.,y_..-.-_ 53 GPUN Specification No. SP-1101-12-039, " Acceptance Criteria for OTSG Re-pair Tools and Materials." 54 B&W R&D Division Technical' Procedure ARC-TP-526, '" Accelerated Oxidation Procedure of Tubesheet and Tube Materials for the TM1-1 Qualification Program," J. V. Monter, June 21, 1982 (B&W Document ID No. 03-1024013-00). 9 e ) A-4 l ~ S l [ l GPU Nuclear Corporation G A Muclear
- =s=S2g8o Micc:etcwn Pennsylvania 17057 717 944 7621 TELEX 8.: 2386 Writer's Direct Osal Numter-Octcher 25, 1982 5211-82-252 Office of Nuclear Reactor Regulation Attn: John F. Stolz, Chief Operating Reacters Branch No. 4 U. S. Nuclear Regulatory Co=nission Washington, D.C.
20555
Dear Sir:
Three Mile Island Nuclear Station, Unit 1 (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 T.4I-1 GTSG Repair Drawings The enclosed B&W drawings were requested by the Franklin Research Corpora-tion for use in their evaluation of our OTSG kinetic repair. These drawings are considered proprietary for the reasons discussed in the enclosed affidavit.
It is requested that they be protected fron public disclosure in accordance with the provisions of 10 CFR 2.790.
s Sincerely, m
D.
- ki 1 Director, til-1 EDH:MJG:vj f Enclosures cc:
R'. Jacobs 4;Ast t0f
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f#lgI PDR ALCCK 05000299 I
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PDR GPU Nuclear Corporation is a suosiciary of the Generat Puche Ut:hties Corporatien
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~~s Babcock &V.1(cox AFFICAVIT OF JAMES H.
TAYLOR A.
My name is James H. Taylor.
I am Manager of Licensing in the Nuclear Power Generation D'ivision of Bebcock & Wilcox, and as i<:h I am authorized to execute this Affidavit.
B.
I am familiar with the criteria applied by Babcock & Wilcox to de-termine whether certain information of Babcock & Wilcox is proprietary and I am familiar with the procedures established within Babcock & Wilcox, particularly the Nuclear Power Generation '0ivision (NPGD), to ensure the proper application of these criteria.
C.
In determining whether a Babcock & Filcox document is to be classi-fled as proprietary information, an initial determination is made by the unit manager who is responsible for originating the document as to whether it f alls within the criteria set forth in Paragraph D hereof.
If the information falls within any one of these criteria, it is classified as proprietary by the originating unit manager.
This initial determination is reviewed by the cognizant section manager.
If the document is designated as proprietcry, i t is re-viewed again by Licensing personnel and other management within NPGD as designated by the Manager of Licensing to assure that the regulatory requirements of 10 CFR Section 2.790 are met.
D.
The foll'owing information is provided to demonstrate that the pro-visions of 10 CFR Section 2.790 of the Commission's regulations have been considered:
(i)
The information has been held in confidence by the Babcock &
Wilcox-Company.
Copies of the document are clearly identified as proprietary.
In addition, whenever Babcock & Wilecx transmits the information to a customer, customer's agent, potential customer or regulatory agency, the transmittal re-quests the recipient to hold the information as proprietary.
Also, in order to strictly limit any potential or actual customer's use of proprietary information, the following 1
- =O
Babcock &Wilcox AFFIDAVIT OF JAMES H.
TAYLOR (Cont'd) provision is included in all proposals submitted by Babcock
& Wilcox, and an applicable version of the proprietary provision is included in all of Babcock & Wilcox's contracts:
" Purchaser may retain Company's Proposal for use in connection with any contract resulting therefrom, and, for that purpose, make such copies thereof as may be necessary.
Any proprietary information concerning Company's or its Suppliers' products or manufacturing processes which is so designated by Company or its Suppliers and disclosed to Purchaser incident to the performance of such contract shall remain the property of Company or its Suppliers and is disclosed in confi-dence, and Purchaser shall not publish or otherwise disclose it to others without the written approval of Company, and no rights, implied or otherwise, are granted to produce or have produced any products or to practice or cause to be practiced any manuf acturing processes covered thereby.
Notwithstanding the above, Purchaser may provide the l
NRC or any other regulatory agency with any such pro-(
prietary information as the NRC or such other agency I
may require; provided, however, that Purchaser shall first give Company written notice of such proposed' disclosur2 and Company shall have the right to amend such proprietary information so as to make it non-pro-prietary.
In the event that Company cannot amend such proprietary information, Purchaser shall, prior to disclosing such information, use its best effor,ts to obtain a commitment from NRC or such other agency to have such information withheld from public inspection.
(2)
L
~
Babcock &Wilcox AFFIDAVIT OF JAMES H. TAYLOR (Cont'd)
Company shall be given the right to participate in pursuit of such confidential treatment."
(ii) The following criteria are customarily applied by Babcock &
Wilcox in a rational decision process to determine whether the information should be classified as proprietary.
Information may be classified as proprietary if one or more of the following criteria are met.
a.
Information reveals cost or price information, commercial strategies, production capabilities, or budget levels of Babcock.& Wilcox, its customers or suppliers.
b.
The information reveals data or material concerning Babccck
& Wilcox research or development plans or programs of present or potential competitive advantage to Babcock &
Wilcox.
c.
The use of the information by a competitor would decrease his expenditures, in time or resources, in designing, producing or marketing a similar product.
d.
The information consists of test data or other similar data concerning a process, method or component, the application or which results' in a competitive advantage to Babcock &
Wilcox.
e.
The information reveals special aspects of a process, method, component or the like, the exclusive use of which results.in a competitive advantage to Babcock & Wilcox.
f.
The information contains ideas for which patent protection may be sought.
(3)
)
~
Babcock &M5fcox AFFIDAVIT OF JAMES H.
TAYLOR (Cont'd)
The document (s) listed on Exhibit "A",
which is attached hereto and.made a part hereof, has been evaluated in accordance with normal Babcock & Wilcox proceduros with respect to classification and has been found to contain information which falls within one or more of the criteria enumerated above.
Exhibit "B",
which is attached hereto and made a part hereof, specifically identifies the criteria applicable to the document (s) listed in Exhibit "A".
(iii) The document (s) listed in Exhibit "A", which has been made avail-able to the United States Nuclear Regulatory Commission was made available in confidence with a request that the document (s) and the information contained therein be withheld from public disclosure.
(iv) The information is not available in the open literature and to the best of our knowledge is not known by Combustion Engineering, EXXON, General Electric, Westinghouse or other current or potential domestic or foreign competitors of B&W.
(v) Specific information with regard to whether public disclosure of the information is likely to cause harm to the competitive position of Babcock & Wilcox, taking into account the value of the information to Babcock & Wilcox; the amount of effort or money expended by Babcock & Wilcox developing the information; and the ease or difficulty with which the information could be properly duplicated by others is given in Exhibit "B".
E.
I have personally reviewed the document (s) listed on Exhibit " A" and have found that it is considered proo'rietary by Babcock & Wilcox because it contains information which falls within one or more of the criteria enumerated in Paragraph D, and it is information which is customarily held in confidence and protected as proprietary in-formation by Babcock & Wilcox.
This report comprises information utilized by Babcock & Wilcox in its business which afford Babcock
& Wilcox an oppo'rtuni ty to obtain a competi tive advantage over (4)
L
Babcock &Wilcox those who may wish to know or use the information contained in the document (s).
3 ff/ d
/
JAMESH.TA[0R State of Virginia)
)
SS.
Lynchburg City of Lynchburg)
James H. Taylor, being duly sworn, on his oath deposes and says that he is tne person who subscribed his name to the foregoing state-ment, and that the matters cnd facts set forth in the statement are true.
fhfh ggl
[
JAM [S"H. TAY(dk swornbef)r Subscribed g-day of X.aJ.,)e me this M
1982.
I m
Notary Public in and or the City of Lynchburg, State of Virginia My Commission Expires ta /f /7M 8
(5) e 1
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Babcock &Wilcox Exhibit A Drawing s of Three Mile Island-l details and dimensions Steam Generators containing design t
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i Babcock &Wilcox Exhibit B Description of Material Aeolicable Criteria Dwg No. 131112E-12 Shell and Tube c&e
. Sheet Attachment Assembly Owg No. 131102E-12 Longitudinal e&e Section Thru Steam Generator
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