ML20058K523

Flaw Evaluation & Weld Overlay Designs for Ei Hatch Unit 1 Spring 1990 Refueling Outage

ML20058K523
Person / Time
Site:	Hatch
Issue date:	06/26/1990
From:	Cofie N, Gustin H, Tang S STRUCTURAL INTEGRITY ASSOCIATES, INC.
To:
Shared Package
ML20058K520	List: HL-1158, Forwards Rev 0 to SIR-90-039, Flaw Evaluation & Weld Overlay Designs for Ei Hatch Unit 1 Spring 1990 Refueling Outage. Rept Details IGSCC Exam Results,Weld Overlay Design & Evaluation of Weld Shrinkage Stresses ML20058K523
References
SIR-90-039, SIR-90-039-R00, SIR-90-39, SIR-90-39-R, NUDOCS 9007060316
Download: ML20058K523 (100)

Text

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ENCLOSURE

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Report No.: SIR-90-039' i

, Rev. No. 0 Project No.: GPCO-18Q.  :;

June, 1990 ,

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l Flaw Evaluation and Weld Overlay  ;

Designs for Plant E. I. Hatch Unit 1 l Spring 1990 Refueling Outage <

Prepared by:

Structural Integrity Associates Prepared for:

Georgia Power Company 1

Prepared by: Date: hEl. / f9  ;

N. G. Cofie. '

Prepared'by: -> Date: Skh40  ;

H'. . stin Prepared by: ./ A Date: b

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. T g i Reviewed by: / [) Date: (!25 '/O P. ' C. Rlcca'rdella / ' '

po d / Date: k71/ 90 g ' A'. YGiannuzzi /

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TABLE OF CONTENTS Section Page

1.0 INTRODUCTION

. . . . . . . . .. . . . . . . . . . . 1-1 2.0 REPAIR AND EVALUATION CRITERIA . . . . . . . . . . .,2-1 2.1 Repair Description . . . . . . . . . . . . . . . 2-1  !

2.2 Design of Standard Weld Overlay Repairs . . . . . 2-2 2.3 Evaluation of Flaws in Weld Overlays . . . . . . 2 3.0 STRESS COMPONENTS AND COMBINATIONS l 3.1 Summary of Stress Components . .. . . . . . . . 3-1  !

3.2 Stress combination for Weld Overlay Design . . . 3-1  ;

4.0 WELD OVERLAY DESIGN EVALUATION AND RESULTS . . . . . 4-1 i 4.1 Design of Standard' Weld Overlay Repairs . . . . . 4-1 4.2 Evaluation of Flaws in Weld Overlay Repairs . . . 4-3 l 4.3 Evaluation of one-Sided Weld Overlays . . . . . . 4-8 )

4.4 Evaluation of Reduced Ferrite Level In '

Initial Weld Layer . . . . . . . . . . . . . . . 4-9 5.0 EVALUATION OF WELD OVERLAY SHRINKAGE STRESSES . . . . 5-1 5.1 Background . . . . . . . . . . . . . . . . . . . 5-1

5.2 Weld overlay Shrinkage . . . . . . . . . . . . . 5-4 5.3 Analysis of Weld Overlay Shrinkage Stresses . . . 5-5 5.<4 Evaluation of Shrinkage Stress Effects -. . . . . 5-7 6.0

SUMMARY

AND CONCLUSIONS . . . . . . . . . . . . . . . 6-1  ;

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7.0 REFERENCES

. . . . . . . . . . . . . . . . . . . . . 7-1 APPENDIX A - UT Inspection Results . . . . . . . . . A-0 APPENDIX B - Weld-Overlay Design Drawings . . . . . . B-0 APPENDIX C - Revised Fracture Mechanics Evaluation for Unoverlayed Welds . . . . . . . . . C-0 i

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4 b LIST OF-TABLES Table Pace  !

i 3-1 Stress Components for Flawed Weld Location . . . 3-3 I i

3-2 Piping System Geometry Data . . . .. . . . . 3-4 4-1 Weld Overlay Design & As-Built Dimensions . . . . 4-2 4-2 Summary of-Flaws in Overlays . . . .- . . . . 4-4 4-3 ASME Code Stress Evaluation Results for .

One-Sided Weld Overlay

. . -. . . . . . . . 4-10 5-1 Summary of the As-Built' Weld overlay Shrinkage . . 5-9 5 Recirculation Loop A Weld Shrinkage Stress . . . 5-10 l I

5-3 Recirculation Loop B Weld Shrinkage Stress . . . 5-11 l 5-4 Service Stresses in Unoverlayed, Flawed Welds . . 5-12 l

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a o LIST OF FIGURES Ficure Eagg 4-1 Illustration of Short Weld' Overlay Design at Cast Pumps and Valves . . . . . . . . . . 4-14 4-2 Hatch Unit 1 Short Overlay Finite Element Model . . 4-15 4-3 Predicted Ferrite Requirements Versus Carbon Content to-Provide Significant Resistance Against SCC for Grade CF-8 Castings . . . . . . . . 4-16 4-4 Combined Influence of Carbon Content and Percent Ferrite on IGSCC Resistance . . . . . . . . 4-17 5-1 Remote Effects of Weld Overlay Shrinkage . . . . 5-13 5-2 Effects of Weld Overlay Shrinkage on Parallel Piping . . . . . . . . . . . . . . . 5-14 5-3 Measurement of Weld Overlay Shrinkage . . . . 5-15 5-4 Typical Schematic Model cf BWR Recirculation System . . . . . . . . . . . . . . . 5-16 5-5 Finite Element Model of the Recirculation System Piping - Hatch Unit 1 (Element Numbers) . . . . 5-17 5-6 Finite Element Model of the Recirculation System Piping - Hatch Unit 1 (Node Numbers) . . . . . 5-18 SIR-90-039, Rev. O 111 STRUCTURAL INTEGEETY ASSOCIATESINC

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1.0 INTRODUCTION

During the Spring 1990 refueling outage, Georgia Power Company (GPC) performed ultrasonic examinations on recirculation, residual heat removal (RHR) and reactor water clean-up (RWCU) J system welds at Plant E. I. Hatch Unit 1 (Hatch Unit 1) in accordance with GPC's commitment related to NRC Generic Letter 88-01 and NUREG-0313, Rev. 2 (1). These inspections included flawed, unflawed and previously overlayed repaired welds in these systems. During these inspections, flaws believed to be due to' intergranular stress corrosion cracking (IGSCC) were detected in twelve 28-inch diameter recirculation pipe welds which required weld overlay repairs. IGSCC flaws in five of these welds were previously detected during the Winter 1985/86 refueling outage but were left unrepaired based on flawed pipe evaluations (2];

hence a total of seven new flawed welds were identified in the 28-inch diameter recirculation pipe welds during the 1990 refueling outage. Four unrepaired flawed welds which were mitigated by induction' heating stress improvement (IHSI) during-the 1985/86 outage were also inspected. No changes were found in the flaws in these welds compared to previous inspection results.

These welds have thus remained stable since-the 1985/86 outage.

Flaw descriptions of these four welds were previously provided after the 1985/86 refueling outage [2]. No other new flaws were detected in the smaller diameter pipes of the recirculation, system nor in the-other piping system welds which were included in the inspection program. A summary of the f' law descriptions for the twelve 28-inch diameter recirculation flawed welds is presented in Appendix A.

Weld overlay repairs have been applied at Hatch Unit 1 since 1982. Thirty-five (35) overlays were either newly applied or- -

built-up and surface finished during the 1985/86 outage [2]. Of these thirty-five overlays, four were in the reactor water cleanup (RWCU) system, three were in the residual heat removal (RHR) system and the remaining twenty-eight (28) were in the SIR-90-039, Rev. 0 1-1 M

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l recirculation system. In addition, an overlay was applied to an unflawed weld (Wald No. 24B-R-12) to enhance inspectability.

Three more weld overlays were applied to IGSCC-flawed welds on the RWCU system during the Spring 1987 outage (3). During the-Fall 1988 outage, overlays were applied to two safe end-to-nozzle l welds (4) in the recirculation system. In addition, during the 1988 outage, the RWCU system inside containment (from the drywell penetration- X-14 to the RHR suction line) was replaced eliminating all the seven previously applied weld overlays on I

this. system. During the replacement of this portion of the RWCU '

system, two welds which had undergone repairs during installation, (Weld Nos. 6-D-1 and 6-D-9) were also repaired by weld overlays. These weld repairs were not associated with IGSCC and as such the weld overlays of these two welds are not classified as IGSCC repairs. t In summary, a total of thirty-four weld overlays associated with IGSCC were present at Hatch Unit 1 prior to the 1990 outage.

These include the overlay on RHR weld 24B-R-12, which although not IGSCC-related, is classified and inspected as a NUREG-0313,-

Rev. 2 Category E weldmsnt. Two overlays applied on the newly ,

replaced RWCU system during the 1988 outage are also not IGSCC-related. Twelve additional overlays associated with IGSCC were applied during the 1990 outage bringing the total number of IGSCC-related overlays to forty-six (46) at Hatch Unit 1. There also remain four flawed, unoverlayed but IHSI-mitigated welds in the plant, which remained unchanged from prior inspections.

A selected number of the pre-1990 outage overlays were inspected during the 1990 outage per GPC's in-service inspection.

commitment. There was no evidence of cracks propagating into the-overlays in these welds. Minor flaws associated with lack of fusion between weld beads, which occurred during the overlay repairs, were observed in some of these overlays. They were evaluated per the requirements of the ASME,Section XI (5].

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The purpose of this report is to document the design / analysis and evaluation activities conducted on the twelve 28-inch diameter

. flawed welds identified during the 1990 outage. The evaluations of the pre-1990 weld overlay repairs and flawed welds have been documented previously (2,3,4). Flaws identified in weld overlays repaired before the 1990 outage, but inspected during the ' 1990 outage, will also be docenented. Section 2 of this report presents the weld overlay design and flaw evaluation criteria.

Section 3 presents stress components and stress combination data.

Information on pipe component dimensions is also included in this section. Section 4 presents evaluation methods and results. A comparison of design and as-built weld overlay dimensions is also presented in Section 4. Section 5 addresses the system-wide i effects of weld overlay shrinkage on unoverlayed welds in the system. The analysis which was performed on the Hatch Unit 1 recirculation system is presented together with predicted shrinkage-induced stress data. Sections 6 and 7 present. ,

summary / conclusions and references used in this evaluation.

Appendix A- provides -the UT inspection results for the . twelve 28-inch diameter flawed welds and Appendix B presents the weld overlay design drawings for these welds. Appendix C provides updated flawed pipe analysis of the IHSI-mitigated circumferentially flawed welds.

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2.0 REPAIR AND EVALUATION CRITERIA 2.1 ReDair DescrIDtion The twelve weld overlays applied at Hatch Unit 1 during the-1990 refueling outage were designed and repaired as " standard" weld ,

overlays. The repairs were made by increasing the pipe wall  ;

chickness through the deposition of weld metal circumferentially i around the water-backed pipe in the weld region using the machine  !

GTAW welding process. The weld metal used for the weld overlay application was Type 308L stainless steel containing 0.02 wt. %_ 1 maximum carbon with controlled delta ferrite content in order to provide resistance to IGSCC propagation. In addition to providing the required wall thickness to restore the ASME Code safety margin, the welding process in the water-backed condition ,

also produces a strong compressive residual stress pattern on the inside of the pipe which provides further resistance to IGSCC.

The overlay repair for each flawed weld was carefully controlled using the'following steps in order to assure the integrity of the

,verlay:

1. Surface preparation-by grinding of existing weld crowns and any local protrusions to blend smoothly into the base metal plus the removal of oxides and other foreign materials from the area to be overlayed.

2. Iayout of weld overlay per the design drawing by i punchmarking appropriately on the pipea

3. Liquid penetrant examination of the surface to be overlayed to assure surface is free of indications in accordance with ASME,Section XI (5).

4. Measurement of wall thickness on each side of the weld to be overlayed using UT techniques.

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'5. Delta ferrite content measurement of the completed first layer - to meet the ferrite content requirement of 7.5 FN.

Where the ferrite level was below 7.5 FN, the extremely low carbon level was demonstrated to provide equivalent IGSCC resistance at the reduced ferrite level. (See Section 4.4 for detail)

6. Surface preparation of the completed weld overlay to assure I

adequate surface contour and smoothness for UT examination. l l

7. Measurement of the final overlay thickness by UT techniques.-

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8. Liquid penetrant examination of the' final overlay surface in accordance with ASME,Section XI.

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9. Volumetric examination of the completed weld overlay repair _

and part of the original pipe wall in accordance with UT-techniques developed by EPRI.

'2.2 Desian of Standard Weld Overlav Renairs l The requirements for design of. weld overlay repairs are defined in NUREG-0313, Rev. 2 (1). The analytical bases for the design of.the repairs are in accordance with the requirements of ASME Section XI, IWB-3641 [5) as specified in NUREG-0313. Weld j overlay repairs are considered to be acceptable long term repairs to :IGSCC-flawed weldments if they meet a conservative set - of- 3 design assumptions which qualify them as " standard" weld l l

overlays, in accordance with NUREG-0313. The three - principal design requirements to qualify a weld overlay as a " standard" weld overlay and, therefore, as an ;ISCC Category E weld in 1 accordance with Reference 1 are:

1. The design basis flaw for the repair is a

! circumferentially oriented flaw which extends 360*

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! around the component, and is through the original l

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component wall. This sonservative assumption f eliminates concerns about the reliability of the .i ultrasonic inspection which initially. identified the' flaw. In addition, potential concerns. about .the toughness of the original butt weld material are not applicable, since no credit is taken in the design '

process for. the load carrying capability of the remaining component wall ligament.  :

2. As. required by ASME Section XI,. IWB-3641 (5), a combination of internal pressure, deadweight and seismic stresses is used in the design of weld overlay repairs.- Thermal and other secondary stresses are not required to be addressed, since the toughness of the original butt weld material is not a concern for a standard weld overlay, and since no credit is taken for the remaining uncracked ligament in the original pipe wall.

3. Following the repair, the surface finish of the repair.

must. be sufficiently smooth to allow ultrasonic examination through the overlay material and into a

, portion of the original wall. The purpose of this j examination'is, in part, to demonstrate that the repair- )

l thickness does not degrade with time due to continued ..

flaw propagation.

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2.3 Evaluation of Flaws in Weld Overlavs 1

During UT examination of pre-1990 outage overlays and also the J l

overlay repairs performed during the 1990 outage, indications .

were identified in some of these overlays. Most of these indications were classified as lack of fusion between weld beads during'the overlay application with no measurable width. These ,

indications are evaluated against the requirements of ASME~ 1 '

Section XI, IWB-3514.3 [5] to show that they are acceptable. A SIR-90-039, Rev. 0 2-3 e i

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,.- -,. i boat sample was taken from the weld overlay on Weld 28A-2 for metallurgical examination. This examination revealed that the.

- reported UT indications in the overlay were actually porosity in the weld metal. The-ASME Section III, Appendix VI standards for rounded indications were used to evaluate the acceptability of.

the. observed porosity, i

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L 3.0 STRESS COMPONENTS AND COMBINATIONS i

'3.1 Summary of Stress Comoonents The stress information required for weld overlay design and . j analysis was taken from Reference 6. The components, considered l in these designs and analyses included pressure, dead weight, i seismic . (OBE) ,- and thermal expansion stresses. These components are - presented in Table 3-1 for each weld requiring repair or evaluation. I 3.2 Stress Combinations for Weld Overlav Desian a i

Table IWB-3641-1 of ASME Section XI [5] defines allowable flaw-depth in austenitic steel base metal and associated gas tungsten a arc welds (GTAW) as a function of the stress ratio (Pm+Pb)/Sm.

Thus-the pertinent stress combination for weld overlay design is:

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P, + Pb " pressure + #DW * # seismic Table IWB-3641-5 requires including expansion stresses in the above stress ratio when evaluating flaws in shielded metal arc-or submerged arc weldments (SMAW or SAW), to account for the concern of~ Ootentially low t::,ughness in these flux weld materials.

However, since the design basis for the Hatch Unit 1 weld overlays assumes a through wall flaw extending 360*, no credit for the original flux weld material is taken, and the overlays are entirely GTAW weldments. Therefore, the flux weld toughness e

concern does not apply and thermal stresses are not needed for the overlay design. Thermal stresses are included in Table 3-1 for completeness, however.

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i The geometry of each pipe size (outside diameter and nominal wall i thickness) is suutarized in Tacle 3-2. In calculating the stress, the meesured wall thickness was used if it was available.

Otherwise nominal wall thickness was used in calculating the i stresses.  ;

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Table 3-1 )

Stress Components for Flawed Weld Locations STRESS COMPONENTS WELD NUMBER PRESSURE DEADWEIGHT THERMAL SEISMIC (OBE) 12AR-G-4 6667 214 6284 1814 12BR-A-4 6667 1443 7407 1680 12BR-E-4 6667 1448 7424 1821 20B-D-4 5391 643 3176 1790

• 28A-2 6731 571 727 857 28A-4 6836 433 396 762 28A-6 7292 664 935 1038 28A-7 6250 285 870 .1018 ,

28A-8 7292 586 937 573 281. 7302 856 555 1097 28B-8 7214 396 710 956 288-9 7214 639 720 647 28B-10 7292 577 732 933 28B-13 7302 497 573 1489 28B-14 7302 469 630 1557 28B-15 7302 904 767 1156 P

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Table 3-2 I Piping System Geometry Data I

Nominal Nominal Pipe Site Pipe 0.D. Wall Thickness )

System fin.) _ fin.i fin.) .

I RWCU 6 6.628 0.5494 Recirculation 12 12.746 0.693 RHR 20 20.00 0.937 '

Recirculation 22 22.00 1.100 i

,' RHR 24 24.00 1.150 Recirculation 28 28.00 1.213  ;

(Suction) i Recirculation 28 28.00 1.390 (Discharge)

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I D 4.0 WELD OVERLAY Dr.1IGN EVALUATION AND RESULTS I Twelve (12) new weld overlay repairs vera applied to IGSCC-like flaw indications during the 1990 outage at Hatch Unit 1. These twelve new weld overlays are in 28-inch diameter recirculation j system pipe welds. Six of these weld overlays are in Loop A and ]

six weld overlays are in Loop B. In addition, minor flaws were detected in five pre-1990 weld overlays. The following sections ,

describe the design analyses and as-built evaluations performed  !

for the new overlays and flaw evaluations performed for the pre-1990 overlays.  ;

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4.1 pasion of standard Wald overlay __Renairs Where flaws requiring repair were detected during the present outage, weld overlay repairs were designed based upon the criteria described in Section 2. The applied stress ratio used in the weld overlay design was calculated from data presented in Reference 6 with stress components combined as defined in Section 3 of this report. The flaw was assumed to extend 360' circumferentially and to be through the original pipe wall. The program pc-CRACK (7) was used to size the weld overlay utning ASME Section XI, IWB-3640 criteria. Low carbon level, elevated ferrite weld wire was utilized in the overlay welding so that the design thickness could include credit for the first welded layer.

Design and as-built dimensions for the new (1990 outage) weld overlays are presented for comparison in Table 4-1. All weld overlay design drawings are included in Appendix B. The as-built (post-surface finish) thickness for each overlay was compared with the design thickness to determine acceptability of each overlay. The dimension listed in the as-built columns represent the minimum of all data points measured at each weld overlay.

The thicknesses of the as-built overlays meet or exceed the ,

design values in all cases.

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Table 4-1 Wald Overlay Design and As-Built Dimensions Design As-Built Design As-Built Weld Length Length Thickness Thickness Number (in.)

_ (in.) (in.) (in.)

28A-2 6.40 7.60 0.46 0.50 28A-4 6.40 7.88 0.45 0.48 28A-6 6.20 7.61 0.44 0.54 28A-7 3.50 4.20 0.49 0.75 28A-8 3.50 5.31 0.43 0.465 28A-14 5.70 7.20 0.52 0.595 28B-8 3.50 4.60 0.44 0.57 28B-9 3.50 4.75 0.44 0.545  ;

38B-10 6.20 7.60 0.44 0.48 28B-13 3.50 4.35 0.52 0.59 28B-14 3.50 4.79 0.52 0.60 28B-15 6.70 8.31 0.52 0.62 ,

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4.2 Evaluation of Flaws In Weld Overlav Recairs 1

During the ultrasonic examinations of weld overlay repairs during l the 1990 outage at Hatch Unit 1, embedded flaws were identified

'in a total of seven weld overlay repairs. These flaws and the i weld overlays are summarized in Table 4-2. Five of the flawed r(pairs were applied during previous outages. These cre discussed in section 4.2.1. The remaining two flawed repairs were applied during the 1990 outage. One of the 1990 weld overlay repairs was evaluated as acceptable by IWB-3500. This weld (28B-9) is discussed in section 4.2.2. A metallurgical

" boat sample" was removed from the other weld overlay, weld (28A-2), and the repair was shown to be acceptable based upon the results of metallurgical examination of that sample. The evaluation of 28A-2 is summarized in section 4.2.3. All seven of the weld overlays with identified embedded flaws were shown to be acceptable for continued operation without further repair.

4.2.1 Evaluation of Defects in Pre-1990 Outage Weld Overlays at Hatch Unit 1 During ultrasonic examinations of the weld overlay repairs applied prior to the current outage at Hatch Unit 1, flaw indications were found in five of the overlays. These overlays and the associated indication notifications (INFs) are as follows:

Weld No. Indication Notification Number 1B31-1RC-28B-4 190H1024 1E11-1RHR-24A-R-13 190H1016 1E11-1RHR-24B-R-12 190H1035 1B31-1RC-22BM-4 190H1013 1B31-1RC-12AR-F-2 190H1011 SIR-90-039, Rev. 0 4-3 m

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i Table 4-2

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Summary of Flaws in Overlays Wald t III L(2) Evaluated a I3) '

Number (in.) (in.) (in.)

12AR-F-2 1.45 11.95 0.1 9

22BM-4 1.68 3,4 0.1

-24A-R-13 lg48 1.2 0.1 24B-R-12 1.72 4.15 0.1 28A-2 1.85 3 x 360*I4) M) 28B-4 2.15 11.65 0.1 l 28B-9 1.74 4.25 0.1 ,

Notes:

1) t = As-built original pipe wall thickness plus overlay thickness. ,

2) L = Combined length of all flaws in the overlay.

3) Evaluated "a" is half the flaw width, conservatively assumed to be 0.1 in, for all flaws (actual width too small to '

measure).

4) Post repair UT examination revealed three axial locations in the repair where indications extending 360' around the pipe for a width of approximately 1/2 inch existed in the first l welded layer. Metallurgical examination determined that these flaws were due to porosity in the first welded layer-(see Section 4.2.3).

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j The flaw indications in these overlays were generally characterized as lack of fusion between weld beads during the overlay application. They are not connected to the original IGSCC flaws in the pipe wall.

1 These flaws have been evaluated under the requirements of ASME Section XI, IWB-3500 (5) utilizing two approaches. In the first )

approach, the flaws were assumed to be planar flaws while in the second approach they were assumed to be laminar flaws. In either l case, the requirements of the Code were satisfied, indicating that the overlays are acceptable for continued operation and that the flaws do not undermine the original design . basis of the  ;

overlays.,

4.2.2 Evaluation of Defects in Weld Overlay Applied to Weld 1B31-1RC-28B-9 As identified in INF No. 190H1045, flaw indications were found in the new weld overlay applied to Weld 1B31-1RC-28B-9 during the post-application ultrasonic examination. The flaw indications were characterized as interbead lack of fusion and they are not connected to the original flaws for which the weld overlay was designed.

The flaws have been evaluated to the requirements of ASME Code,Section XI, IWB-3500 (5) by considering them either as planar or laminar flaws. In either case, the requirements of the Code are satisfied indicating that the subject weld overlay is acceptable for service without modification.

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4.2.3 Evaluation of Flaws Identified in the Weld overlay on Weld 1B31-1RC-28A-2 1

The original UT examination of the overlay applied to weld j 1B31-lRC-28A-2 identified laminar indications which were too large to be acceptable by Section XI, IWB-3500 (5). For this reason, a boat sample was removed from the overlay to identify the exact nature of the flaws. A review was performed of a metallurgical report (8) prepared by Babcock & Wilcox (B&W),  !

which documented the laboratory examination of the boat sample. l The sample was directly over an apparent laminar or lack of bond type indication in the weld overlay material, which was detected ultrasonically during the post-repair examination. Reference 8 reported that the observed UT indications were in fact not laminations or lack of bond defects, but were due instead to porosity in the first welded layer of the repair. The report further concluded that the observed porosity would have no significant effect on the mechanical properties of the weldment, '

and is acceptable by ASME Section III, Appendix VI standards for rounded indications.

Structural Integrity's review of the Reference 8 report and related data from the site, resulted in the conclusion that the observed flaws in weld 28A-2 are acceptable without repair or ,

further action beyond repairing the cavity left by the boat sample. This conclusion is based upon the following facts in ,

addition to the B&W observations described above:

1. The acceptability of the indications with respect to ASME Section III, Appendix VI which was reported above and independently verified by SI.

2. The weld overlay design thickness of 0.46" is maintained outboard of the identified porosity flaws.

The integrity of the weld overlay repair would not be degraded by the observed flaws, even if they produced a SIR-90-039, Rev. 0 4-6 6 N

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i significant reduction in the mechanical strength of the weld layer. .

3. The weld overlay material and the underlying pipe material are still inspectable ultrasonically.

consequently, it is still possible to monitor the IGscc flaw in the base metal, as recommended by NUREG-0313, Rev. 2 (1). It is also possible to monitor the observed porosity indications for changes, although  ;

none are expected.

4. The observed indications appear to be an isolated occurrence, in that similar indications were not

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reported in the weld overlays on other welds.

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5. There is no indication of connection of the observed porosity with the original IGSCC indications in the base metal.

6. Reference 8 estimates that the observed porosity results in a reduction in cross sectional area of less than 5%. On this basis, there is no reason why the first welded layer (which contains the observed porosity) cannot be considered as part of the design thicknera of the weld overlay repair, since the normal requirements for considering the first layer were met.

(i.e., the original pipe surface was shown to be clean by dye penetrant examination, and the 'first welded layer was shown by actual measurement to contain delta ferrite of at least 7.5 FN).

The following actions Were taken by GPC as a result of the UT indications and subsequent boat sample results from the weld overlay repair of 28A-2:

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.l

1. The UT characteristics of the observed porosity indications, as noted during the current examination of this i weld overlay, were recorded and carefully documented for comparison with any future similar " laminar" indications in future weld overlays. Such documentation will aid in the resolution of weld overlay indications in the future.

2. It is believed that indications such as those revealed by the metallurgical examination of the boat sample could be due to contamination of weld material or pipe surface. The procedures associated with dye penetrant examination of pipe surfaces prior to overlay repair and with weld material control were reviewed to determine whether it was desirable  ;

to add controls or hold points to these procedures to increase assurance of clean surfaces and materials.

3. During future ultrasonic examinations of the repair to weld 28A-2, the " laminar" indications will also be examined in detail, in order to provide added assurance that the weld overlay is not degraded. ,

In summary, it was concluded that the observed porosity does not degrade the . integrity of the weld overlay repair on weld 28A-2, and consequently, no further repair activity was required. This  !

conclusion is based upon the observations in Reference 8, and.on the observation that a standard overlay containing the design thickness of 0.46 inches is maintained outboard of the identified porosity indications.

4.3 Evaluation of One-Sided Weld Overlavs Six of the weld overlay repairs applied during this outage, as well as several from prior outages, were applied to pipe-to-valve or pipe-to-pump weldments, in which the component side of the weld is a material generally considered to be highly resistant to IGSCC (10, 11). For this reason, and to avoid welding on the SIR-90-039, Rev. 0 4-8 M

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cast material, which could lead to opening up potential casting The overlay defects, a short weld overlay repair has been used. and ends on pipe side of the weld, only covers the susceptible, fusion the crown of the weld side ofbetween the weld the (see weld Figurecenterline 4-1).

This and the line on the component report summarizes a generic analysis which has section of the to validate this design concept with respect to been performed ASME Code rules.

model which was a finite element Figure 4-2 illustrates Hatch constructed to bound the one-sided weld overlays of the applied at overlay were Unit 1. The wall thicknesses on either sidt and a flaw was assumed, through the original chosen as minimums, zone (HAZ) on the pipe j pipe wall and 360* Worstin the heat affected '

case loads for the subject overlays at side of the weld. and the resulting Hatch Unit 1 were applied to the model, stresses were evaluated at two critical sections 4-2.

on the and Primary short side of the overlay, as indicated in Figure determined by linearizing primary plus secondary stresses were itical actual stresses from the finite element model along the cr Code made to applicable ASME sections. A comparison was allowable stress values (12).

i The resulting stress comparisons at the two critical sect ons are listed in Table 4-3. It is seen from this table that the stresses meet the applicable ASME Code allowables.

In Initial Weld Laver 4.4 Evaluation of Reduced Ferrite Level basis An evaluation was performed by SI to document the technical il for acceptance of low carbon, reduced ferrite Type 308L sta n ess initial steel weld metal as Reference 1 approved material for the This evaluation was weld overlay layer at Hatch Unit 1.

containing necessitated by the fact that one heat of weld metal, pad, ferrite when deposited as a weld greater than 10FN occasionally produced ferrite levels between 6.0 and 7.5 FN in 4-9 SIR-90-039, Rev. 0 INC

Table 4-3 ASME Code Stress Evaluation Results for one-sided Weld overlay Section Section Code i 1 2 Allowable Primary Stresses P. 15.24 kai 16.75 kai 16.95 kai

• P. + Pb 18.38 kai 20.21 kai 25.43 ksi Secondary Stresses:

P1 + Pb +Q 43.74 ksi 40.77 kai 50.85 ksi e

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the first weld overlay layer of some of the 28-inch diameter recirculation system weld overlay repairs. Due to the radiation exposure concerns related to requiring one or more additional weld overlay layers if the first layer was disregarded as an IGSCC barrier, an alternative evaluation approach was employed, utilizing Reference 1 guidance, to allow for a limited reduction in ferrite level in the weld provided that sufficient reduction in carbon. level is also present. This approach is described in the following paragraphs.

The evaluation of the acceptability of reduced ferrite, low carbon Type 308L stainless steel consisted of a review of the open literature. This literature review, documented in References 9-11, illustrates that one is technically justified in reducing the ferrite level in this weld metal without reducing the IGSCC resistance if there is a sufficient reduction in the carbor, level. This carbon-ferrite trade-off results from the fact that the materials-related cause of IGSCC in these austenitic stainless steels in the EWR environment is the fact that excess carbon is in solution during the welding or otherwise heat treating of these materials. This excess carbon combines with the chromium which is in solution, thereby forming chromium carbidos preferentially along the grain boundaries. The reduced chromium zone at the grain boundaries, or " chromium depleted zone", is often sufficiently reduced in chromium so that this region is no longer " stainless". A material is identified as

" sensitized" in this condition and IGSCC becomes a real possibility.

Ferrite in the alloy helps prevent the chromium depletion in two ways. Firstly, the equilibrium chromium level in ferrite is much  !

greater than in austenite. Consequently, " chromium depletion" l due to carbide formation has a much less damaging effect at  !

ferrite grain boundaries in an aurtenitic stainless steel which contains ferrite. Secondly, the carbon diffusion in the ferrite SIR-90-039, Rev. 0 4-11 M

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I is much greater than in the austenite in these steels.

Consequently, most chromium carbide forms at ferrite-austenite or j ferrite-ferrite grain boundaries rather than on austenite-austenite boundaries, where " chromium depletion" is a significant concern.

Low carbon austenitic stainless steel alloys, such as Type 316 nuclear grade stainless steel, attain their excellent resistance l to IGSCC because they contain no more than 0.02 wt. % carbon in the alloy. This family of alloys is identified by Reference 1 as 1 resistant to IGSCC due to a reduced carbon level. Reference 1 also identifies Type 308L stainless steel weld metal, containing 0.035 wt. % carbon and 7.5 FN ferrite, as resistant to IGSCC.

This reference states further, in the case of cast alloys, the further reduction in ferrite to 5 FN is allowable, depending on carbon content and other factors.

Studies have been performed by the Electric Power Research Institute and by General Electric Company to examine the carbon-ferrite trade-off in imparting IGSCC resistance to duplex austeniti iase stainless steel weld metal. References 9 through 11 identity some of that research and Figures 4-3 and 4-4 from References 10 and 11 represent graphical presentations of the IGSCC resistance which can be obtained as one changes the carbon and the ferrite levels in these alloys. One can observe from these figures that there is a strong carbon-ferrite trade-off in providing equivalent resistance to IGSCC in this class of duplex stainless steels. Figure 4-4 illustrates that for austenitic stainless steel castings containing 0.02 wt. % carbon or less, approximately 5.5% ferrite produces an alloy which is highly resistant to IGSCC even in the severely sensitized condition.

One observes from this curve that at a carbon level of 0.035~wt.

%, (as is allowed by Reference 1), more than 12% ferrite would be required to achieve the same resistance to IGSCC. Figure 4-3 illustrates that a decrease in carbon level from 0.035 wt. % to 0.02 wt. % results in a decrease of approximately 2% in the SIR-90-039, Rev. 0 4-12 .

6 t'

ASSOClKrmINC

ferrite level necessary to provide an equivalent resistance to IGSCC.

These results illustrate that there is a carbon-ferrite adjustment one can employ for producing an equivalent resistance to IGSCC in the BWR environment. The Nuclear Regulatory Commission has recognized that trade-off in NUREG-0313, Rev. 2 (1). The industry has utilized this carbon-ferrite trade-off in specifying acceptance levels for use of cast components as conforming materials by following the guidance presented in Figures 4-3 and 4-4 (10', 11).

At Hatch Unit 1, a heat of Type 308L stainless steel has been I used which contains 0.019 wt. % carbon (Heat # XT5941), and which has produced an as-deposited ferrite content which has been measured at between 6.0 and 7.5 FN ferrite in some beads. Based upon the results presented above, in order to obtain an IGSCC resistance equivalent to that for a heat conta.\ning 7.5 FN ferrite and 0.035 wt. % carbon, one is technically justified in reducing the ferrite to 5.5 FN without reducing the IGSCC resistance in this heat of material below the minimum specified in NUREG-0313, Rev. 2. The results indicate, therefore, that one may use this heat of weld metal for the first overlay weld layer provided no read.ing in that layer is below 5.5 FN ferrite. If a L single reading is below 5.5 FN, but auuve 5.0 FN, one may still 3 accept the la'fer provided that two additional measurements in the q immediate vicinity of the low measurement are equal to or greater '

than 5.5 FN.

SIR-90-039, Rev. 0 4-13 INTEGRITY mg

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REPAIR DETAILS I

Figure 4-1. Illustration of Short Weld overlay Design at Cast Pumps and Valves l

l.

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(Reference 11)

SIR-90-039, Rev. 0 4*17 "

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5.0 EVALUATION OF WELD OVERLAY SHRINKAGE STRESSES 5.1 Backaround 5.1.1 Causes of Weld overlay Shrinkage Stresses I

Stresses develop in a piping system after application of one or more weld overlays due to the weld shrinkage at the overlays.

These stresses are system-wide, and are similar in nature to

]

restrained free-end thermal expansion or contraction stresses, j The level of stresses resulting from weld overlay shrinkage are a direct result of the number and location of the weld overlays, the shrinkage per overlay, and the piping system geometry. Axial shrinkage produces tensile secondary stresses at locations co-linear with the overlay, and predominantly bending secondary stresses at locations which are separated and not co-linear with the welding location (e.g., locations separated by an elbow, see Figure 5-1). In addition, weld overlays can produce stresses at ,

fixed points in parallel runs of piping if the two runs are tied together by a stiff run (see Figure 5-2). This latter situation is typical of 12" recirculation system risers. The highest stressed point in a recircu2 .. system with several weld overlays is typically at recircu; lon riser to inlet nozzle connections. Weld overlay shrinkage in a vertical run of such a riser produces bending on the horizontal run leading to the inlet  ;

nozzle. This bending stress is typically highest at the nozzle-to-pipe or pipe-to-safe end weld.

Three aspects of the weld overlay application determine the magnitude of weld overlay shrinkage which will be produced. The first of these is the pipe size. Larger pipes (with correspondingly thicker walls) are stiffer and shrink less than do smaller lines. Typically the amount of shrinkage measured in 28" lines is roughly 1/4 to 1/5 of that produced on 12" pipe for the same weld overlay design. Consequently, shrinkage stresses SIR-90-039, Rev. 0 5-1 6 M

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

J 1

I predicted in 28" pipe are also only a small fraction of the worst stresses predicted in 12" pipe.

The second factor which contributes to the magnitude of the '

observed weld overlay shrinkage is the length of the overlay.

For the same pipe size, a longer overlay will produce greater axial shrinkage and (depending on system geometry) larger stresses than would a shorter overlay.

The final factor which has an effect on the shrinkage is the ,

number of weld layers applied to produce a particular overlay thickness. Field. measurements suggest that the bulk of the shrinkage occurs as a result of application of the first two ,

welding layers. Subsequent layers have progressively less effect. This suggest that the magnitude of the shrinkage is related to the volume of metal cooling at any one time, compared to the amount (including original pipe wall) which has already solidified.

5.1.2 Effects of Weld Overlay Shrinkage In ASME Code terminology, the stresses produced by the shrinkage of weld overlays are secondary stresses. However, they are essentially constant with operating time, so there are no ,

official ASME Code limits on this stress component. Nonetheless, they could potentially increase the susceptability of unoverlayed welds to future IGSCC and decrease the effectiveness of stress remedies such as IHSI. Therefore, it-has become common p ctice to - evaluate these stresses in systems with relatively large numbers of overlays, to assure that they remain within reasonable bounds. This is done for flawed and unflawed weld locations as

• discussed below.

SIR-90-039, Rev. 0 5-2 ASSOCIATESINC

O

• Unflawed Locations At unflawed locations, the stress imposed by shrinkage will ,

combine with existing applied and residual stresses to determine susceptibility to crack initiation, e.g., by the IGSCC mechanism.

In the case of weld locations which havc not received residual stress mitigation (e.g., with IHSI) the pre-existing inside l surface tensile residual stresses may combine with the tensile component of stress due to shrinkage to make the location very >

susceptible to crack initiation. Even if the location has been ,

treated with IHSI, the superposition of the tensile stress due to shrinkage on the IHSI residual stress pattern will tend to reduce the effectiveness of IHSI in inhibiting crack initiation. The shrinkage stresses at such locations are tabulated and compared [

to the expected ID surface compressive stresses due to IHSI, to  ;

assess the potential effect of the overlay. on unflawed welds.

Flawed Locations '

At unoverlayed flawed weld locations, similar effects to those on unflawed locations will be experienced. The tensile stress superimposed on the location's stress field may make the location more prone to further crack initiation. In addition, the shrinkage stress may act in concert with applied and residual stresses to promote further crack propagation and to increase the rate of that growth. To evaluate this ef fect, stresses due to weld overlay shrinkage are added to applied and residual stresses in performing crack growth calculations to demonstrate ,

acceptability of an existing flaw without repair.

Such evaluations are not required for flawed location which have been weld overlay repaired, since it is generally believed that the residual stress benefits of the weld overlay will overwhelm the global shrinkago effects, and since the design basis for the overlay is a 360* through-wall crack in the original weldment and SIR-90-039, Rev. 0 5-3 ASSOCIATESINC

l the overlay itself is highly resistant to IGSCC, even in the presence of tensile stresses. l 1

5.2 Weld overlav Shrinkace In order to predict the magnitude of the stresses resulting from weld overlay shrinkage, it is necessary to measure or estimate the amount of shrinkage which occurred during the weld overlay application process. This was done manually at Hatch Unit 1.

First, the design length of each weld overlay was " laid out" or, the weld to be repaired. The centerline of the existing butt weld was determined, and the design length of the design overlay in each direction (upstream and downstream of the weld centerline) was marked on the pipe using punch marks at several azimuthal locations. An additional set of marks was placed approximately 1/2" to 1" beyond each end of the design overlay length, typically at 4 azimuthal locations separated by 9 0' .

This latter set of 8 punch markings (4 on each end of the overlay region) was used to determine shrinkage.

The distance between each azimuthal pair (upstream-downstream) of punch marks was measured using a vernier caliper (see Figure 5-3). The weld overlay was then applied between the inner set of markings, which define design length. Following the completion of overlay welding, the distance between the outside set of punch marks was again measured with vernier cC ipers. The difference '

between the before and after welding measurements for each azimuthal location was tabulated, and the four differences were averaged. The average values from these measurements for each overlay are tabulated as the weld overlay axial shrinkage in Table 5-1, and were used as input into the analysis discussed below to determine shrinkage-induced stress at all unoverlayed locations in the recirculation system.

SIR-90-039, Rev. 0 5-4 1

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.i 5.3 Analysis of Weld overlav Shrinkaae Siresses 5.3.1 Background As pointed out earlier, the stresses produced by weld overlay shrinkage are not confined to the vicinity of the repair, but rather can affect remote locations. Consequently, it is necessary to consider the system as a whole, and to consider all ,

overlay repairs, in determining the stresses which will result from overlay shrinkage.

The analytical approach used in this evaluation includes preparation of a finite element model of the entire piping system. A typical model is shown in Figure 5-4. The actual weld overlay shrinkages measured at the repair sites are input at the nodes corresponding to repaired welds in the form of " cold elements", which simulate the mechanical shrinkage observed in the field through use of negative pseudo-thermal expansion.

Mechanical anchors and rigid restraints are built into the model, as appropriate for the piping support system, but no other loads are included.

(

After preparation of the above model, the stresses at all points ,

in the system are calculated elastically. Because the stress at welds is of concern to IGSCC (rather than within components), all stress indices are set equal to 1. 0. Also, in combining axial -

and bending stresses, absolute summation is used.

Typically, stresses calculated in the above manner for piping larger than 12" are rarely larger than 1 ksi. However, it is not

! unusual to see stresses in the 12" risers which are predicted to be in the vicinity of 15-20 ksi or larger. The highest stressed locations are almost always at the junction of riser to inlet nozzle and occasionally at the junction of riser to ring header.

SIR-90-039, Rev. 0 5-5 M ASSOCIATEINC

There are several conseivatisms in the above type of analysis.

First of all, since the stress is elastically calculated, j stresses may be overpredicted. Refining the approach to include i consideration of the true material stress-strain behavior would give more reasonable results. Secondly, nozzles are typically modeled as rigid and the flexibility of elbows and other ,

components may be underpredicted.

5.3.2 Modeling Details The A140R SUPERSAP finite element computer program (13) was used to calculate the piping stresses due to weld overlay shrinkage in the recirculation system. Figures 5-5 and 5-6 present the model y with element numbers and node nurbers. Since loop A and loop B of the recirculation system are mirror images of each other, the same model was applied to analyze the shrinkage effect for both loops.

The actual weld overlay shrinkages measured at the repair sites as summarized in Table 5-1, were input at the nodes corresponding to repair welds in the form of " cold elemento". This approach is used to simulate the mechanical shrinkage observed in the field through the use of negative pseudo-thermal expansion.

Temperature differences at the cold element were calculated as:  ;

0 AT = ,3 (1) where AT is the temperature difference from the reference temperature at the cold element, 6 is the as-built veld overlay shrinkage, a is the coefficient of thermal expansion, and L is the length of the weld overlay element.

l SIR-90-039, Rev. 0 5-6 6 L M ASSOCIATESINC l

_ _ _ . ._. _ _ . . _ _ _ _ ~

I For boundary conditions, all nozzles are assumed to be rigidly anchored. Also, support is not included in the model at the l location of the recirculation pump.  ;

5.3.3 Results Resulting shrinkage stresses in the Hatch Unit I recirculation system welds are summarized in Tables 5-2 and 5-3. From these '

tables, it is seen that shrinkage stresses in the unrepaired welds are small in the 28-inch welds, (less than 2 ksi) .

Shrinkage stresses in the 22-inch ring header are also less than [

2 ksi. The highest shrinkage stress is in the riser welds. The highest stress is 13.26 kai in the 'c' riser and 12.12 ksi in the

'H' riser at the cross on the ring header. '

5.4 Evaluation of Shrinkace Stress Effects Because of the design basis assumption of a 360* through-wall flaw used for all overlay designs, as discussed in Section 4 of this report, the above shrinkage stresses will have no effect on the weld overlay designs. They are secor

• cy stresses and thus the application of high toughness weld metal eliminates any low toughness concern which would require their inclusion in weld overlay design. Also because of the relatively small magnitude j of shrinkage stresses in all unoverlayed welds, and the application of IHSI at Hatch Unit 1, the effects of weld overlay shrinkage on uncracked welds are not considered significant. I There are three Category F welds in the recirculation system l (12AR-G-4, 12BR-A-4 and 12BR-E-4) which were found to have circumferential cracks in the 1985/86 outage. All three of these welds had stress improvement by IHSI in that outage. They were reinspected.in the current outage and found to contain no change in the indications observed in 1985/86.

1 i

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The total service stresses, including the revised shrinkage stresses in these three welds are listed in Table 5-4. Flaw evaluation for these three welds was redone to reflect the new shrinkage stress values, and is reported in Appendix c. This analysis uses the same methodology and criteria es was used in 1986 to evaluate the flaw indications, including taking credit for IHSI in the crack growth evaluation. The revised evaluation shows that the new shrinkage stresses do not alter the results of the evaluation. One other flawed weld (20B-D-4) located on the RHR suction was unaffected by the revised shrinkage atress analysis. The flaw evaluation for this weld is therefore the same as that performed during the 1985/86 outage (2).

P 4

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- SIR-90-039, Rev. 0 5-8 ASSOCIATESINC

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Table 5-1  !

3 -

- Summary of the As-Built Weld Overlay Shrinkagec u Pre-1990 L1990 ,

Outage -Outage

• Weld- WOL Length Shrinkage Shrinkage-Number. _ (in.) _ (in.) (in . )-

12AR-F-2: 3.82 0.146 12AR-F-3 4.19, 0.276 12AR-F-4 4.53 0.335 12AR-G-3 4.52 0.259 12AR-H-2 ~3.81 0.141

• 12AR-H-3 4.47 0.348 12AR-H-4 4.41 0.391

-12AR-J 4.19 0.256

.12AR-K-2 4.76. 0.228 12AR-K-3 4.28 0.365 12BR-B-3 4.00 0.329 12BR-C-2 -4.07 0.156 12BR-C-3 3.72 0.344 12BR-C-4 4.13 0.317 12BR-D-2 4.32 0.332 l 12BR-D-3 4.25 0.330 ,

12BR-E-2, 3.98 0.158 12BR-E-3 4.08 0.287 22AM-1 6.33 0.014 22AM 6.75 0.000 22BM-1 7.78 0.013 22BM-4 6.64 0.039 28A-2 7.60 0.0425' 28A-4 7.88 0.1775 i 28A-6 7.61 0.0900 28A 4.20 0.0698 28A-8 5.31 0.0875, 28A-10 4.64 0.036

=28A-12' 5.00 -

0.066 28A-14. 7.20 0.3625' 28B-3' 6.15 0.091 28B 5.97 0.058 28B 4.60- 0.0163.

28B-9 4.75- 0.2325 28B-10 7.60 0.2893 28B-11 4.72 0.089 28B-13 4.35 0.1158

-28B-14 4.79 -0.0150 (1)-

28B-15 8.31 -0.2300 (1) 28B-16 5.00 0.046

~ (1) Average measured value indicated growth after weld overlay

~

repair. A value of zero was conservatively used in i shrinkage stress analysis.

i SIR-90-039, Rev. 0 5-9 -

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. Table 5-2 Recirculation Loop A Weld' Shrinkage Stress Weld Stress Weld Stress .

Number (ksi) Rumber (ksi) 1 28A-1 0.13 12AR-F-1 6.98-

'28A-2 --

12AR-F-2 --

4 28A-3 0.09 12AR-F -- i 2BA-4 --

12AR-F-4 --

28A-5 0.13 12AR-F-5 2.54 28A-5A 0.25 12AR-G-1 5.40 28A-6 --

12AR-G-2 4.18 28A-7. --

12AR-G-3 --

28A-P --

12AR-G-4 5.97 2SA-9 0.21 12AR-G-5 7.22 28A-10 --

12AR-H-1 12.12 28A-11 0.078 '12AR-H-2 --

28A-12 --

12AR-H-3 --

28A-13 0.23 12AR-H-4 --

28A-14 --

12AR-H-5 7.52 28A-15 O.47 12AR-J-1 4.22

.-28A-16 0,5 12AR-J-2 4.19 28A-17 1.56 12AR-J-3 --

22AM-1 --

12AR-J-4 7.18 L

22AM-2 1.66 12AR-J-5 8.54 22AM-3 1.07 12AR-K-1 4.87 22AM<:4 --

12AR-K-2 --

12AR-K-3 --

12AR-K-4 2'.91 12AR-K-5 3.64 l

l l

I SIR-90-039, Rev. 0 5-10 ->

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+ .

Table 5-3 i u- Recirculation Loop B Wald Shrinkage Stress n

,e i- Weld Stress Weld Stress Number (ksi) Number (ksi)

, 28B-1 0.17 12BR-A-1 5.84 f 28B-2 0.17- 12BR-A-2 1.19 p 28B --

12BR-A-3 0.69  ;

tp 28B-4 --

12BR-A-4 1.97 28B-5 0.94- 12BR-A-5 2.29 1 ~

28B-6 0.86 12BR-B-1 5.68 28B-7 0.36 12BR-B-2 2.08-

, 28B-8 --

12BR-B-3 --

28B-9 --

12BR-B-4 5.53 '

28B-10 --

12BR-B-5 6.44 288-11 --

12BR-C-1 13.26 '

28B-12 0.36 12BR-C-2 --

E 28B-13 --

12BR-C-3 --

28B-14 --

12BR-C-4 --

28B-15 --

12BR-C-5 --

l 288-16 --

12BR-D-1 5.51 i 28B-17 0.58 12BR-D-2 --

28B-18 1.6' 12BR-D-3 -- i 22BM-1 --

12BR-D-4 5.60 22BM-2 1.48 12BR-D-5 6.51-22BM-3 1.11 12BR-E-1 8.48 22BM-4 --

12BR-E-2 --

12BR-E-3 --

12BR-E-4 6.4 , l 12BR-E-5 -- . j e

i a

-: 1

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l i

l 1

l l

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j SIR-90-039, Rev. 0 5-11

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~ ~ , . .. . . . - . .- -

r; I

s Table 5-4 .

-Service Stresses in Unoverlayed, Flawed Welds '

Nominal Weld- Thickness Press. DW Thermal Shrk. Total Number (in.) 1ksi).. (ksii (ksi) (ksi) (ksi) 12AR-G-4 'O.693 6.67 0.21 6.28 5.97 19.13 12BR-A-4 0.693 6.67 1.44 7.41 1.97 17.49-  ;

a r i

12BR-E-4 0.693 6.67 1.45 7.42 6.40 21.94 s

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l SIR-90-039, Rev. O 5-12 1

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e A 1 V/H //A l-L WELD DVERLAY SHRINKAGE AT C PRODUCES TENSILE CTRESS AT A BENDING STRESS' AT B. 1 i

s Figure 5-1. Remote Effects'of-Weld Overlay. Shrinkage .

i SIR-90-039, Rev. 0 5-13 ,

M ,

ASSOCIATESINC

l-L

l. ,

n

n r

/ , ..

d B

A t .. .

I I

i 1

WELD SHRINKAGE AT A PRODUCES UPWARD BENDING AT'S

)

l Figure:5-2. Effects of' Weld Overlay Shrinkage On Parallel Piping SIR-90-039, Rev. 0 5-14 e

M ASSOCIATESINC

- - _ _ _ _ - - - _ _ - - _ _ _ _ _ - - - - - _ _ - _ _ _ _ _ - - - - _ _ _ _ - . _- - _ _ _ _ _ __ _ _ - _ _ - - - .a

. PUNCH MARKS (SEE SECTION A-Al- I s A

.l l

, 1 A

X1

(' l L l X4 X2 l l

l t ,

l. .

l: X3 ..<

SECil0N A-A PUNCH HARKS AT 4 AZINUTHAL LOCATIONS.

( 90* APART )  :

1. PLACE PUNCH NARKS BEFORE BEGINNING WELDING.

2. NEASURE DISTANCE BETWEEN EACH PAlR

, -( UPSTREAN/DOWNSTREAN ) 0F NARKS BEFORE AND ,

l AFTER WELDING L  :

L Figure 5-3. Measurement of Weld overlay Shrinkage l-i SIR-90-039, Rev. 0 5-15

, M ASSOCIATESINC

I

!! ' s c- ,

l b l N / -

VESSEL INLET

1. ' y  %%  % s j

/

VESSEL DUTLET VESSEL DUTLET

/

Q , J \

RHR 99g RHR l

._. ~- _- .

PUMP 'PUNP -

l I

Figure 5-4. Typical Gehematic Model of BW Recirculation System  ;

i SIR-90-039, Rev. 0 5-16 ASSOCIATESINC

. - . . - - ~ . . . . . .- - - - . -

i

[ ~ ,

= .:

.ef/. -

t>,

a I

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ti

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p  ! .

.. " I

%ly * '

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.. U \

< , l u

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Figure 5-5. Finite Element Model of the Recirculation System Piping - Hatch Unit 1 (Element Numbers) i

{

m SIR-90-039, Rev. 0 5-17 UfTEGRrFY AssocwESINC

r I

~

wee

\

~.

C

~ = ~

W.

~ * ~

$ ~

a g 4 4 m h t 4 .

• 8 ,

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% g O

%g. * '

e a C k- '

4 g- g g3 '

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1

-l

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2 -n au u

1 Figure 5-6. Finite Element Model of the Recirculation System Piping - Hatch Unit 1-(Node Numbers) i 1

SIR-90-039, Rev. 0 5-18 9 N

ASSOCIRFESINC

6.0

SUMMARY

AND CONCLUSIONS Ultrasonic (UT) examinations performed at Hatch Unit i during the 1990' outage identified flaws judged to be -IGSCC in the vicinity ,

of sixteen piping welds. Of these sixteen flawed welds, twelve were on the 28-inch recirculation piping system, three were on the 12-inch risers and one was on the RHR system. IGSCC in nine of these flawed welds have been detected in previous outages and hence, seven new flawed welds were identified during the 1990 outage. All seven of the new flawed welds were located in the 28-inch recirculation piping.

The twelve 28-inch flawed welds were repaired using weld overlays -

leaving four unrepaired flawed welds at Hatch Unit 1. All the overlays were designed as standard overlays per the requirements of.NUREG-0313, Rev. 2. A comparison of the as-built and designed overlay dimensions indicates that all the as-built dimensions exceed the design dimensions. The addition of these twelve overlay repairs brings the total number of IGSCC-related overlays I at Hatch Unit 1 to 46 at the end of the 1990 outage. Two other overlays at Hatch Unit 1 are not IGSCC-related.

.UT examinations were also performed on pre-1990 overlays as well as the overlays applied during the 1990 outage. There was no evidence of cracks propagating into the overlays. Small indications identified in some of these overlays were mainly due to lack of fusion between weld beads during the repair process h and were not connected to the original design basis flaws. One weld overlay, containing weld related defects, had a

. metallurgical sample removed to confirm the size and distribution of these non-relevant d'fects.

e The remainder of these flaws were evaluated per the requirements of ASME Section XI and were found to be acceptable, indicating that all overlays at Hatch Unit 1 to

.be adequate.

SIR-90-030, Rev. 0 6-1 hs 6 i m- ,

[ .. ,

.The axial shrinkage resulting from the application of the weld-I

overlays during the 1990 outage was added to previously measured

• I shrinkage from prior outages and the results were used to perform

a. shrinkage analysis of-the recirculation system. The shrinkage

, stresses obtained1 from this evaluation were -found to have increased only slightly from those calculated from previous R

analysis. The shrinkage stresses were added to other service stresses to perform a " flawed pipe" evaluation of the four unrepaired flawed welds at Hatch Unit 1. The evaluation showed

! that the service stresses at these flawed weld . locations are  ;

changed only slightly from the results reported earlier and hence no crack growth is predicted at these locations. These welds received induction heating stress improvement (IHSI) during the e 1985/86 outage and since then, the flaws have not shown any growth. These welds were therefore returned to service without any additional mitigation, t

'In summary, all flawed welds identified at Hatch Unit 1 have been evaluated by ASME Section XI and NUREG-0313, Rev. 2, and.

determined to be acceptable for long term, continued operation.

k b

SIR-90-039, Rev. 0 6-2 t, . M l ASSOCIATESINC.

7.0 REFERENCES

1. NUREG-0313, " Technical Report on Material Selection and Processing Guidelines for BWR Coolant Pressure Boundary ,

Piping," Final' Report, Revision 2, U.S. Nuclear Regulatory Commission, January 1988 and associated USNRC Generic Letter 88-01.

2. SIR-86-002, " Evaluation of IGSCC Flaw Indications and Weld Overlay Designs for Plant E. I. Hatch Unit 1 - Fall.1985/86 >

Maintenance / Refueling Outage," Revision 2, Structural Integrity Associates, April 1986.

3. SIR-87-014, " Flaw Evaluation and Repair Design for Plant E.

I. Hatch Unit 1 -

Spring 1987 Outage," Revision 1, Structural. Integrity Associates, June 1987.

4. SIR-88-036, " Plant Hatch Unit 1 -

Transmittal of Recirculation Inlet Safe End Weld Overlay Design Packages,"

Revision 0, Structural Integrity Associates, November 1988.

5. Americi.n Society of Mechanical Engineers Boiler & Pressure Vessel Code,Section XI, 1986 Edition Including All Addenda.

6. General Electric Company, "Results of Seismic . Evaluation,

-As-Built Recirculation Piping Including Replacement Actuator for F031 Discharge Valve", Design Memo 170-113, dated September 26, 1984.

7. Structural Integrity Associates Computer Program, pc-CRACK, Version ~2.0 dated April, 1989.

8. Babcock & Wilcox, " Laboratory Examination of a Weld Overlay '

from the Edwin I. Hatch Nuclear Station", RDD:91:5194-01:01, ,

May 1990,

9. EPRI Topical Report, Research Project T303-1, " Technical uustification For Extended Weld Overlay Design Life", May, 1987.

10. -Structural Integrity Report No. SIR-87-021, " Evaluation of IGSCC_ Resistance of Cast Components at Peach Bottom Atomic Power Station Unit'3",-August, 1987.

'11. ASTM Special Technical Publication 756, " Stainless Steel Castings", Prepared - By General Electric Company For ASTM, American Society For Testing and Materials, 1982, pp. 26-47.

12. 'American~ Society Mechanical Engineers, Boiler and Pressure Vessel Code, Section III, 1986 Edition Including All Addenda.

13. Algor Interactive Systems, Inc., SUPERSAP Computer Software, Version 9.000, July 1989.

l SIR-90-039, Rev. 0 7-1 l' M

, DITEGRITY ASSOCIATESINC

- . ;; .y T

Y l:

7 APPENDIX A UT Inspection Results i

e t

SIR-90-039, Rev. O A-0 DrTEGRITY ASSOCIATESINC

, -.- l

t. 1 j

WELD NO.: 1831 1RC-28A-2 ' )

- NOM. PIPE SIZE: '28' '

NOM. PIPE THK.: 1.213'

)

UPSTREAM DOWNSTREAM CONFIGURAT)ON: SAFE END PIPE l

DESCRIPTION OF FLAWS OUTAGE LENGTH DEPTH ORIENT. LOCATION DISPOSmON

' (IN.) (%)

1988 0.90 22 CIRC. SAFE END LEAVE AS.lS 5.20 14 CIRC, SAFE END 1.25 19 CIRC. PIFE SIDE 1990 0.80 25 CIRC. SAFE END STANDARD OVERLAY APPtian -

5.50 37 CIRC, SAFE END 1.25 15 CIRC. PIPE SIDE 4.00 19 CIRC. PIPE SIDE I

J A-1

1 y

E 1

l WELD NO.: 1831 1RC.28A-4 4

NOM. PIPE SIZE: 28* ,

NOM. PIPE THK.: 1.213' l

l UPSTREAM DOWNSTREAM . '

CONFIGURATION: ELBOW - PIPE _j DESCRIPTION OF FLAWS '

OUTAGE LENGTH DEPTH ORIENT. LOCATION DISPOSITION (IN.) (IN.)  !

l 1988- SPOT 'O 10 AXIAL ' PIPE SIDE . LEAVE AS-IS /

0.36 0.12 AXIAL PIPE SIDE SPOT 0.07 AXIAL ELBOW SIDE "

j SPOT 0.09 AX1AL PIPE SIDE SPOT 0.12 AXtAL - PIPE SIDE SPOT 0.12 AX1AL PIPE SIDE 0.20 0.11 AXIAL PIPE SIDE 1990 -0.10 0.25 AX1AL PIPE SID2 STANDARD OVERLAY APPLIED 0.15 - 0.22 AX1AL PIPE SIDE O.15 0.25 AXlAL ELBOW SIDE 0.15 0.32 AX1AL PIPE SIDE l 0.15 0.33 AXtAL PIPE SIDE i 0.20 0.24 AX1AL PIPE SIDE.

0.15 0.20 AX1AL PIPE SIDE 6.85 0.25 CIRC. PlPE SIDE .j 5.00 0.22 CIRC. PIPE SIDE 0.15 0.15' AX1AL PIPE SIDE 6.50 0.30 CIRC. PIPE SIDE 3.25 ' O.70 CIRC. PIPE SIDE 4

A-2

. \

WELD NO.: .1831 1RC-28A-6 NOM. PIPE SIZE: 28' NOM. PIPE THK.: - 1.213' UPSTREAM DOWNSTREAM CONFIGURATION: PIPE ELBOW DESCRIPTION OF FLAWS

?

OUTAGE LENGTH DEPTH ORIENT. LOCATION DISPOSITION (IN.) (%)

.......... t

~1988- 0.60- 11 AXIAL ELBOW SIDE ' LEAVE AS.lS M ,

0.65 9 AXIAL ELBOW SIDE .

1.00 .22 AXIAL ' ELBOW SIDE 1990 .0.60 -9 AXIAL ELBOW SIDE - STANDARD OVERLAY APPLIED f 0.70 12 AXIAL ELBOW SIDE 0.95 24 AXIAL ELBOW SIDE - i 1.75' 10 - CIRC. PIPE SIDE 2.20 17- CIRC, PIPE SIDE .

.1.20 9 CIRC. PIPE S!DE 4.70 12 CIRC. . ELBOW SIDE 1

l' t ,

i

~

lj L 't' i

i l A-3

i --  ;

o ..

-r i

WELD NO.: 1B31-1RC-28A NOM. PIPE SIZE: 28' NOM. PIPE THK.: 1.213' r

UPSTREAM DOWNSTREAM CONFIGURATION: ELBOW. VALVE

-i DESCRIPTION OF FLAWS OUTAGE LENGTH- DEPTH ORIENT, LOCATION DISPOSITION

' (IN.) -- . (IN.)

~ PRIOR TO 1990 NO REPORTABLE INDICATIONS - NONE REQUIRED 'N 1990 4.90 0.72- - CIRC. . ELBOW SIDE . STANDARD OVERLAY APPLIED :.4 0.25 0.41- AXIAL ELBOW SIDE p-1 i

p l' (

l i..

1 I

A-4

1. s >

-v t . t

- WELD NO.: 1B31-1RC-28A-8 NOM. PIPE SIZE: 28' NOM. PIPE THK.: 1.213" k

UPSTREAM DOWNSTREAM

' CONFIGURATION: VALVE PIPE DESCRIPTION OF FLAWS i

4 OUTAGE LENGTH DEPTH ORIENT, LOCATION DISPOSITION (IN.) . (IN.)

.......... ......... ......... ......... ......... .........................=

.. PRIOR TO 1990 - NO REPORTABLE INDICATIONS - NONE REQUIRED .!

,1990 0.70 0.18- AX1AL PIPE SIDE STAn'DARD OVERLAY APPLIED >

1.00 0.10 AX1AL PIPE SIDE 1.00 0.12' AXtAL PIPE SIDE  ;

13.00 0.45 CIRC. PIPE SIDE 4 i 1

-l A-5

q

'l 1

WELD NO.: 1B31 1RC-28A-14

.1 NOM. PIPE SIZE: 28' l

NOM. PIPE THK.: 1.390 l

1 UPSTREAM DOWNSTREAM CONFIGURATION: ELBOW PIPE .

l l

- DESCRIPTION OF FLAWS i t

OUTAGE LENGTH DEPTH ORIENT. LOCATION DISPOSITION (IN.) (%) ,

PRIOR TO 1990 NO REPORTABLE INDICATIONS NONE REQUIRED 1990 0.98 > 29 AX1AL; ELBOW SIDE STANDARD OVERLAY APPLIED 0.84 29 AX1AL ELBOW SIDE 0.77 37 AX1AL ELBOW SIDE 0.77 26 AXIAL ELBOW SIDE

-0.42 30 AXIAL ELBOW SIDE 0.84 27 AXIAL ELBOW SIDE 0.56 15 AXIAL ELBOW SIDE 0.28 26 AXIAL ELBOW SIDE 0.56 34 AX1AL ELBOW SIDE A-6

WELD NO.: 1831 1RC-288 NOM PIPE SIZE: 28' NOM. PlPE THK.: 1.213' UPSTREAM DOWNSTREAM CONFIGURATION: ELBOW VALVE DESCRIPTION OF FLAWS OUTAGE LENGTH DEPTH ORIENT. LOCATION DISPOSITION (IN.) (IN.)

1988 0.25 - 0.20 AXIAL ELBOW LEAVE AS-IS '

0.25' O.22 AXIAL ELBOW -

1990 0.20 ' O.45 AX1AL ELBOW SIDE STANDARD OVERLAY APPLIED 0.25 0.30 AXIAL ELBOW SIDE 0.20 0.30- AX1AL ELBOW SIDE 0.15 0.85 AX1AL ELBOW SIDE 0.80 0.36 AX1AL ELBOW SIDE 0.15 0.65 ' AX1AL ELBOW SIDE 0.15 0.46 . AX1AL ELBOW SIDE 0.60 0.30 CIRC. ' ELBOW SIDE A-7

)

i l

j I

l WELD NO.: 1831 1RC.288-9 '

1 J

NOM. PIPE SIZE: 28'-

NOM, PIPE THK.: 1.213' UPSTREAM DOWNSTREAM CONFIGURATION: VALVE PIPE

)

DESCRIPTION OF FLAWS -

1 1

L. OUTAGE- LENGTH OEPTH- ORIENT. LOCATION DISPOSITION (IN) (%)

. PRIOR TO 1990 ' NO REPORTABLE INDICATIONS NONE REOUIRED l

1990 4,00 37 CIRC, PIPE SIDE STANDARD OVERLAY APPLIED -

t l- 2.00 13 CIRC. PlPE SIDE

, 6.00 25 CIRC. PIPE SIDE p

S l

-I

)

I; i  ?

l. .h

~

l l

A-8

v- 7

.. e ..

i WELD NO.: - 1B31 1RC-288 10 NOM. PIPE SIZE: : 28' NOM. PIPE THK.; 1.213' l

UPSTREAM . DOWNSTREAM CONFIGURATION: PIPE ELBOW .

t DESCRIPTION OF FLAWS OUTAGE LENGTH DEPTH ORIENT. LOCATION DISPOSITION (IN.) (IN.) ' +t 1988 2.50 0.24 CIRC. ELBOW SIDE LEAVE AS-IS -  ?

0.10 0.24 CIRC. ELBOW SIDE 13.00: 0.21 CIRC. ELBOW SIDE 0.50 0.32 AXIAL ELBOW SIDE 0.50 0.28 AXIAL ELBOW SIDE -

'1990 2.50 0.40- CIRC. ELBOW SIDE STANDARD OVERLAY APPLIED 1.00 0.40 CIRC. ELBOW SIDE  ;

17.00- 0.25 CIRC. ELBOW SIDE 0.45 0.72 AXIAL ELBOW SIDE E 0.45 0.80 AX1AL ELBOW SIDE i

A-9

WELD NO.: 1831 1RC-288-13

' NOM. PIPE' SIZE: 28' NOM. PIPE THK.: 1.390' UPSTREAM DOWNSTREAM -

t CONFIGURATION: PIPE VALVE DESCRIPTION OF FLAWS l4 OUTAGE LENGTH' DEPTH ORIENT. LOCATION DISPOSITION ,

(IN.) _ (%)

PRIOR TO 1990 - NO REPORTABLEINDICATIONS NONE REOUIRED 1990 6.20 47 ~ CIRC. PIPE SIDE - STANDARD OVERLAY APPLIED .

A-10 I'

4

~ t

-^ .-

+. n-i e

WELD NO.: 1831 1RC-288-14 NOM. PlPE SIZE: 28" -

l

~ NOM. PIPE THK.: 1.390' t

UPSTREAM DOWNSTREAM CONFIGURATION: VALVE ELBOW '

DESCRIPTION OF FLAWS (

OUTAGE- LENGTH DEPTH ' ORIENT. LOCATION DISPOSITION

' (IN.) (%)

~ PRIOR TO 1990 NO REPORTABLE INDICATIONS ~ NONE REQUIRED 1990. 15.00 24- CIRC.' ELBOW SIDE STANDARD OVERLAY APPLIED 5.00 28 CIRC. ELBOW SIDE 0.60 24 AXIAL ELBOW SIDE 38 AXIAL ELBOW SIDE  ;

26 AX1AL ELBOW SIDE I

i

[.

l j

~i

'e A-11 i

i

l 3

1 1

l WELD NO.:- 1831 1RC.288-15 l

l NOM. PIPE SIZE: 28' L NOM. PIPE THK.: 1.390' )

UPSTREAM DOWNSTREAM CONFIGURATION: ELBOW PIPE DESCRIPTION OF FLAWS OUTAGE LENGTH DEPTH ORIENT. LOCATION DISPOSITION (IN.) (%)

PRIOR TO 1990 NO REPORTABLE INDICATIONS NONE REQUIRED 1990 0.70 61 CIRC. ELBOW SIDE' STANDARD OVERLAY APPLIED 1.70 55 CIRC. ELBOW SIDE -

18.50 . 55 CIRC. ELBOW SIDE 12.40 66 CIRC. ELBOW SIDE 11.60 61 CIRC. ELBOW SIDE 1.10 62 CIRC. ELBOW SIDE 28.00 64 CIRC. ELBOW SIDE 1.70 55 CIRC. PIPE SIDE .

4.00 61 CIRC. PIPE SIDE 65.20 68 . CIRC. PIPE SIDE 8.90 66 CIRC. PIPE SIDE t

i t

A-12

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

,(

1 i

p 1

1 I

1 1

APPENDIX B l l

1 i

Wald overlay Design Drawings ~ l l

1 l

l i

I s

t l

l l

I l

'l l

.1 1

1

! . j 1

1 SIR-90-039, Rev. O B-0 g M

ASSOCIATESINC' ,

1 l

i

--_-__.__--___A._A_ _ - - - - _ _ _ - _ m----__ --m..__a _ _

• w

= A =!= B~ FLOW

~

l 45' MIN '

TYP y

i

' ' 66',' ' ',' ,

1 5 .

1

/

Y / i l

Safe-end pipe  ;

-i tWELD 1 I

WELD DVERLAY ,

a REPAIR DETAILS .. -

i I_

FLAW DESIGN DIMENSIONS WELD' NUMBER CHARACTER 12ATION t A- B

-1B31-lRC-28A-2 1) Circ 0.8" Long x 0.46" 3.20" 3.20" ^

25% a/t u

, 2)Cire 5.5" Long x 37% a/t

3) Circ 4" Long x 15% a/t  !

4)Cire 1 1/4" Long  ;

x 19% a/t PREPARED BY . . DATE DESCRIPil0N: ,

v_ ' - 6/af/po Standard Weld Overlay Repair Design for Weld 1B31-lRC-28A-2 CHEC DATE (per NUREG-0313, Revision 2)-

jifB M 4/u /eo '

' JOB NO: PLANT / UNIT: REV GPCO-18Q Georgia Power Plant Hatch Unit 1 STROUTURAL 2 DiTEGETY FILE NO:

GPCO-180-301 CVG MO:

GPCO-18Q-001 mac SHT 1 2 0F B-1

e .4  :

NOTES l 1. Weld overlay material is to be type 308L or equivalent, with as-deposited delta ferrite content greater than 7.5 FN.

2. Component surface is to be exainined by dye penetrant method and accepted as clean prior to overlay application in order to include the entire deposited overlay thickness in meeting the design thickness requirement, per NUREG-0313, Revision 2.

3. In the event that the original component surface does not pass the note 2 require-ments, the first deposited weld layer is to be examined by dye penetrant method and accepted as clean before i proceeding with subsequent layers.

4. First weld layer is to have a measured delta ferrite content greater than 7.5 FN.

i

5. Design thickness includes no allowance for surface conditioning operations to facilitate UT inspections.  ;

6. Design length is that required for structural reinforcement; greater length may be required for effective UT inspection. i

~~5)is is to be determined in the field.

OTRUCTURAL IE '

GPCO-180-001, Rev. 2, Page 2 of 2 $ soc ES N C.

B-2

.. _ _ _ . _ _ _ _ - - __- - _-_---.____ --- n . _ _ . _ _ _ - _ _ _ _ - . _ - . _ . _ _ _ - - _ _ _ _ . - - _ - - _ _ . _ _ - -

l 1

I l

=

A = =

8 -- FLOW I 45' MIN j TYP l l

9

, A V4M4PJrfM MME h ,. i

/

Y\\ s / )

4 Elbow Pipe j Q. WELD -

i WELD DVERLAY ,

REPAIR DETAILS .

.+.

FLAW DESIGN DIMENSIONS WELD NUMBER CHARACTER 12ATION t A 3 r 1B . RC-28A-4 8 Axial Flaws Plus 0.45" 3.20" 3.20" l

1) Circ 6.85" Long l  ;

x 19% a/t i 2)Cire 5" Long x 17% a/t 3)Cire 6" Long x 23% a/t 4)Cire 3 1/4" Long '

. . . v Man n /& .

PREPARED BY: . DATE DESCRIPi!DNi

"~

1. /'MI' Standard Weld Overlay Repair Design CHEC for Weld 1B31-lRC-28A-4 (per NUREG-0313, Revision 2)

JOB NO: *: PLANT / UNIT REV GPCO-18Q 'I Georgia Power Plant .

Hatch Unit 1 . i 'g . 2 i >n y FILC NO: DVG N08 N o T;< A 1 bNI .

GPCO-180-301 GPCO-180-002 1 2 0F B-3

l NOTES i

1

1. Weld overlay material is to be type 308L or equivalent, with as-deposited delta ferrite content greater than 7.5 FN.

2. Component surface is to be examined by dye penetrant method and accepted as clean j prior to overlay application in order to

' include the entire deposited overlay .

thickness in meeting the design thickness requirement, per NUREG-0313, Revision 2.

3. In the event that the original component surface does not pass the note 2 require-ments, the first deposited weld layer is to be examined by dye penetrant t method and accepted as clean before  :

proceeding with subsequcnt layers.

4. First weld layer is to have a measured L

delta ferrite content greater than 7,5 FN.

5. Design thickness includes no allowance for surface conditioning operations to facilitate UT inspections.

L >

6. Design length is that required for i structural reinforcement; greater length -

may be required for effective UT inspection.

This is to be determined in the field.

i l EG ITY l GPCO-180-002, Rev. 2, Page 2 of 2 ' ASSOCI AT ES, IN C.

B-4

r i

A == B- FLOW

=

45' MIN TYP i o

/' A 's',',' '''''0

,,, ,, i, , ' I .

/

wb\

/ '

. Pipe Elbow

4. WELD

• WELD DVERLAY REPAIR DETAILS FLAW OESIGN DIMENSIONS VELO NUMBER CHARACiERIZATION t A B  ;

3 Axial Flaws plus 0.44" 3.10" 3.10" 1H31-1RC-28A.6 1)Cire. 1.75" long .

x 10% a/t t 2)Cire. 2.2" long

, x 17% a/t 3)Cire. 1.2" long x 9% a/t 4)Cire. 4.7"'long

, x 12% a/t PREPARED W e CATE DESCRIPT!DN g" >" . *, _ -

'jg,./g Standard Weld Overlay Repair Design for Weld IB31-1RC-28A-6 (per NUREG- '

DATE 0313, Revision 2)

CHEC5D5Leat~

t,(>.cho JD8 NO:

PLANT / UNIT: REV l GPCO-180 Georgia Power Plant t Hatch Unit 1

s' ge s - 2 ,

FILC NO Ov0 NO: xi SHT GPCO-180-302 GPCO-180-003 1 0F 2 D-5

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

{

t NOTES t

1. Weld overlay material is to be type 308L '

or equivalent, with as-deposited delta ferrite content greater than 7.5 FN.

2. Component surfa::e 's to be examined by dye penetrant method and accepted as clean prior to overlay application in order to ,

include the entire deposited overlay thickness in meeting the design thickness  ;

requirement, per NUREG-0313, Revision 2.

3. In the event that the original component surface does not pass the note 2 require-ments, the first deposited weld layer is to be examined by dye penetrant method and accepted as clean before '

proceeding with subsequent layers.

4. First weld layer is to have a measured

delta ferrite content greater than 7.5 FN.

5. Design thickness includes no allowance

.for surface conditioning operations to y facilitate UT inspections.

6. Design length is that required for i structural reinforcement; greater length L may be required for effective UT inspection.

This is to be determined in the field.

i

~

STRUCTURAL l' GPCO-180-003, Rev. 2, Page 2 of 2 'NSOCNES W C.

B-6 l-

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

}

= A = '+ -= 8 45' MIN -

TYP diti%%VG%Sh h

\

/

l i Elbov Valve

4. WELD 9

WELD DVERLAY.

REPAIR DETAILS i FLAW DESIGN DIMENSIONS WELD NUMBER CHARACTER 12AT10N t A l B 1B31-1RC-28B-8 7 Axial Flaws plus 0.44" 3.50" )0.125'

. 1) Cire. 0.6" long x 25% a/t l

q PREPARED N i- DATE DESCRIPfl0N

.-~I/_ 4 A > f. g/p* Standard Weld Overlay Repair Design i

" " ~'

for Weld 1B31-1RC-28B-8 i

CHECKE SY Ig (per NUREG-0313, Revision 2)

\

h W SO l:

1 l JOB N0s , PLANI / UNIT: REV l

~

Georgia Power Plant Hatch Unit 1 2 l FILE NO: DVG NO SHT GPCO-180-303 GPCO-180-004 1 2 0F B-7 1._____________._____________.._..__.. . _

NOTES

1. Weld overlay material is to be type 308L or equivalent, with as-deposited delta ferrite content greater than 7.5 FN.

i

2. Component surface is to be examined by dye penetrant method and accepted as clean prior to overlay application in crder to include the entire deposited overlay thickness in meeting the design thickness requirement, per NUREG-0313, Revision 2.

3. In the event that the original component surface does not pass the note 2 require-ments, the first deposited weld layer is to be examined by dye penetrant method and accepted as clean before proceeding with subsequent layers.

4. First weld layer is to have a measured I delta ferrite content greater than 7.5 FN.

5. Design thickness includes no allowance '

for surface conditioning operations to facilitate UT inspections.

6; Design length is that required for structural reinforcement; greater length may be required for effective UT inspection.

This is to be determined in the field.  !

NNOdiYY GPCO-180-004, Rev. 2, Page 2 of 2 ( Assocl ATES. INC.

B-8 )

'=

A =!= B- FLOW

=

45' MIN -

TYP 4

i S , , '

,' Y, ,',,

, , , 1 $

g

/

\ /

Pipe Elbow tWELD -

WELD OVERLAY REPAIR DETAILS .

FLAW DESIGN DIMENSIONS WELD NUMBER CHARACTERIZATION t A B 2 Axial Flaws plus 0.44" 3.10" 3.10" 1B31-1RC-28B-10 1) Cire 2.5" long x 33% a/t

2) Circ 1" long x 33% a/t *

., 3) Cire 17" long x 21% 4/t .

PREPARED 01: . DATE DESCRIPil0No j, _pe. 3, c gg/p, Standard Weld Overlay Repair Design for Weld IB31-1RC-28B-10 CHEC D8i DATE (Per NUREG-0313, Revision 2)

$ fb SO J08 NO: PLANT / UNIT REV Georgia Power Plant GPCO-180 Hatch Unit 1 M 2 FILE N0 OWG NO: SHT GPCO-180-303 GPCO-180-005 1 0F 2 ,

I B-9 I

1 J

l i

NOTES

i

l. >

t

1. Weld overlay material is to be type 308L or equivalent, with as-deposited delta  :

, ferrite content greater lhan 7.5 FN.

2. Component surface is to be examined by dye penetrant method and accepted as clean  ;

prior to overlay application in order to include the entire deposited overlay .

thickness in meeting the design thickness requirement, per NUREG-0313, Revision 2. -

3. In the event that the original component i surface does not pass the note 2 require-ments, the first deposited weld layer -

is to be examined by dye penetrant method and accepted as clean before proceeding with subsequent layers.

4. First weld layer is to have a measured >

delta ferrite content greater than 7.5 FN.

5. Design thickness includes no allowance for surface conditioning operations to facilitate UT inspections. '

-6. Design length is that required for structural reinforcement; greater length '

may be required for effective UT inspection. ,

This is to be determined in the field.  ;

STRUCTURAL GPCO-180-005, Rev. 2, Page 2 of 2

' NSOC$AT ES I N C.

B-10

I l

=

A =!- =

8 )

i 45' MIN - l TYP o

3 t 533$$$333$33$33'h )

\

E1 w Val e tWELD ,

t WELD OVERLAY.

REPAIR DETAILS FLAW DESIGN DIMENSIONS WELD NUMBER '

CHARACTER 12Ai!0N t A B 1B31-lRC-28A-7 0.49" g-f3.50" 10.125

• l PREPARED BY DATE DESCR!Pfl0N ,

_[ M g/ar/po Standard Weld Overlay Repair Design' for Weld IB31-lRC-28A-7 l DATE (per NUREG-0313, Revision 2)

CHECKEDN8M A~L. skehe- . .

JOB NO: PLANT / UNIIn REV GPCO-18Q Georgia Power Plant M

Hatch Unit 1 g 2 FILE NO DVG NO: ASSOCIATES,DC SHT GPCO-180-308 GPCO-180-010 1 2 ,

OF B 11

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

E NOTES

1. Weld overlay material is to be type 308L or equivalent, with as-deposited delta ferrite content greater than 7.5 FN.

2. Component surface is to be examined by dye penetrant method and accepted as clean prior to overlay application in order to include the entire deposited overlay thickness in meeting the desian thickness requirement, per NUREG-0313, Revision 2.

3. In the event that the original component l' surface does not pass the note 2 require-ments, the first deposited weld layer is to be examined by dye penetrant method and accepted as clean before proceeding with subsequent layers.

4. First weld layer is to have a measured

' delta ferrite content greater than 7.5 FN.

5. Design thickness includes no allowance for surface conditioning operations to f acilitate UT inspections.

6. Design length is that required for structural reinforcement; greater length may be required for effective UT inspection.

This is to be determined in the field.

S STRUCTURAL l GPCO-180-010, Rev. 2, Page 2 of 2 "'

' NSociATES I N C, B-12

. o 1

=

A =l + = 8 45' MIN - l TYP -

/ / / / / / / / / / / / / /,/,/,

a '

Pipe

\

Val e tWELD WELD OVERLAY.

REPAIR DETAILS 4

VELD NUMBER FLAW DESIGN DIMENSIONS f CHARACTER 12AT!0N t A B l

1B31-lRC-28A-8 0,43" 3.50" 2: 0. 3 '

i l:

PREPARED Yi 0 ATE DESCRIPTION:

1. ' MP3ho Standard Weld Overlay Repair Design CHEC 0 CATE for Weld 1B31-lRC-28A-8 l

(per NUREG-0313, Revision 2) l h.:es '

& fbC"hO .

l JOB NO: PLANT / UNITi.

REV GPCO-18Q Georgia Power Plant

• Hatch Unit 1 N 2 FILE NO: OWG NO:

M ASSOCIATESINC SHT GPCO-180-309 GPCO-180-011 1 2 1

0F B-13

1 NOTES j

1. Weld overlay material is to be type 308L or equivalent, with as-deposited delta ferrite content greater than 7.5 FN.

2. Component surface is to be examined by dye penetrant method and accepted as clean prior to overlay application in order to include the entire deposited overlay thickness in meeting the design thickness requirement, per NUREG-0313, Revision 2.

1

3. In the event that the original component {

surface does not pass the note 2 require- '

ments, the first deposited weld layer is to be examined by dye penetrant

-method and accepted as clean before proceeding with subsequent layers.

4. First weld layer is to have a measured delta ferrite content greater than 7.5 FN. .

5. Design thickness includes no allowance for surface conditioning operations to facilitate UT inspections.

6. Design length is that required for structural reinforcement; greater length '

may be required for effective UT inspection.

This is to be determined in the field.

GRITY GPCO-180-011, Rev. 2, Page 2 of 2 ' AS SOCI AT E S. IN C.

B-14

i i

A

=

B~ FLOW

=

45' MIN '

TYP

-[

sumanuens

, +

/

.sx\\ \ /

I Elbow , Pipe tWELD -

WELD DVERLAY ,

i REPAIR DETAILS l

FLAW DESIGN DIMENSIONS WELD NUMBER COMMENTS CHARACTERlZATION i A B 1831-lRC-28A-14 0.52"' 3.35" 3.35" 4

4 4

y g, nIa$'dWeldOverlayRepair' Design [

for Weld 1B31-lRC-28A-14 i CHECKED ST: .. DATE (per NUREG-0313, Revision 2)  !

55 WSYC JOB NO: PLANT / UNITS REV GPCO-18Q Georgia Power Plant . 1

• Hatch Unit 1 i

[8 d'/

FILE NO: DWG NO: .ye .

i SHT GPCO-18Q-310 GPCO-180-012 . 1 2 B-15

NOTES 1

1. Weld overlay material is to be type 308L or equivalent, with as-deposited delta ferrite content greater than 7.5 FN.

2. Component surface is to be examined by dye penetrant method and accepted as clean prior to overlay application in order to include the entire deposited overlay i thickness in meeting the design thickness  :

. requirement, per NUREG-0313, Revision 2. ,

3. In the event that the original component surface does not pass the note 2 require-ments, the first deposited weld layer is to be examined by dye penetrant method and accepted as clean before proceeding with subsequent layers.

4. First weld layer is to have a measured delta ferrite content greater than 7.5 FN.

5. Design thickness includes no allowance for surface conditioning operations to facilitate UT inspections.

6. Design length is.that required for .

structural reinforcement; greater length

• may be required for effective UT inspection.

This is to be determined in the field.

GPCO-180-012, Rev.1, Page 2 of 2 NGRITY

' ASSOCI AT ES. INC.

B-16

l l

-

A =1 B  ;

I 45' MIN - l l

TYP l u

t '

N33333N333$3f,

/  !

N N I Pipe Valve / j 1

( WELD j 3

1 WELD OVERLAY.

REPAIR DETAILS  :

FLAW DESIGN DIMENSIONS WELD NUMBER '

CHARACTERlZATION i A 8 1B31-lRC-28B-9 0.44" 3.5" 20.125 "

i

. PREPARED BY DATE DESCRIPT!0N

• g_ w *, *f#b Standard Weld Overlay Repair Design for Weld 1B31-lRC-2BB-9 CHECKED SY . . . DATE (per NUREG-0313, Revision 2)

_ 55 &,?" $%A pCf(40 JOB NO: PLANT / UNIT: REV GPCO-18Q Ge r Plant y

l' FILE NO: OwG NOi EC SHT GPCO-180-311 GPCO-180-013 1 2 0F B-17

- 4 NOTES 1

1. Weld overlay material is to be type 308L or equivalent, with as-deposited delta territe content greater than 7.5 FN. 3 1

2. - Component surface is to be examined by dye  !

penetrant method and accepted as clean prior to overlay application in order to include the entire deposited overlay thickness in meeting the design thickness requirement, per NUREG-0313, Revision 2.-

1

3. In the event that the original component  :

surface does not pass the note 2 require-ments, the first deposited weld layer is to be examined by dye penetrant method and accepted as clean before  !

proceeding with subsequent layers.

4. First weld layer is to have a measured delta ferrite content greater than 7.5 FN.

5. Design thickness includes no allowance for surface conditioning operations to facilitate UT inspections.

6. Design length is that required for structural reinforcement; greater length may be required for effective UT inspection.

This is to be determined in the field.

GPCO-180-013, Rev.1, Page 2 of 2 b NNOdiYY

& Assocl AT ES. INc.

B-18

I 1

l i )

+

A =l B 1 45' MIN -

TYP i' o

t Mili3333iit'# l i

/

/ l l Pipe l Valv/e .

i

( WELD 1

l 1

WELD OVERLAY.

REPAIR DETAILS FLAW DESIGNDIMENSIONS VELD NUMBER CHARACTERIZATION t A B 1B31-lRC-26B-13 0.52" 3.5" 10.125' d

1 **

PREPARED BY . DATE. 0ESCRIPfl0Ni M/:fi +/N./fo -~

Standard Wald Overlay Repair Design for Weld 1B31-1RC-28B-13 CHECKED GY: DATE (per NUREG-0313, Revision 2) 5.5 NSR _

J08 N0s- PLAMI / UNIT: REV GPCO-18Q Geo aP Plant FILC NO: CVG NO: $HT GPCO-18Q-312 GPCO-18Q-014 1 2 0F B 19

NOTES l

1 l

1. Weld overlay material is to be type 308L j or equivalent, with as-deposited delta 1 ferrite content greater than.7.5 FN. )

2. Component surface is to be examined by dye penetrant method and accepted as clean  !

prior to overlay application in order to

, include the entire deposited overlay l thickness in meeting the design thickness requirement, per NUREG-0313, Revision 2.

3. In the event that the original component surface does not pass the note 2 require-ments, the first deposited weld layer is to be examined by dye penetrant method and accepted as clean before proceeding with subsequent layers.

4. First weld layer is to have a measured delta ferrite content greater than 7.5 FN.

5. Design thickness includes no allowance  ;

for surface conditioning operations to i facilitate UT inspections. l

6. Design length is that required for ,

structural reinforcement; greater length  ;

may be required for effective UT inspection, j This is to be determined in the field.

GPCO-180-014, Rev.1, Page 2 of 2 NGNTY

' ASSOCI AT E S, IN C.  !

B-20 I

• , - - - - - w , ,,, -- , . - - . -, ,n.-, ,<, , - - --

i<

=

A = ~ = 8 45' MIN - l TYP n

t 4333333333$I333f4

/ s N ~

/ I Elbow l Valve /

tWELD t

WELD OVERLAY.

REPAIR DETAILS l

rLAW DESIG'J DIMENSIONS VELD NUMBER COMMENTS CHARACTERIZATION l. A B 1B31-lRC-28B-14 0.52" 3.5" 20.125'

l. .'

t lPREPAREQBY . DATE DESCRIPil0N:

._ [- #4fe b W/g,/h l '

Standard Weld overlay Repair Design for Weld 1B31-lRC-28B-14 CHECKED BY ...._ ... . . , _ _ _ . DATE (per NUREG-0313, Revision 2)

{$Wf Y'N~VC .

l- JOB NO: l' PLANT / UNlts REV GPCO-18Q ha$c$U$Y$1 M 1 FILE NQ: DWG NO SHT GPCO-180-313. GPCO-180-015 1 2 B-21

l l

NOTES

1. Weld overlay material is to be type 308L or equivalent, with as-deposited delta I ferrite content greater than 7.5 FN.

~

2. Component surface is to be examined by dye penetrant method and accepted as clean prior to overlay application in order to ,

include the entire deposited overlay thickness in meeting the design thickness 1 requirement, per NUREG-0313, Revision 2.

3. In the event that the original component surface does not pass the note 2 require-ments, the first deposited weld layer

is to be examined by dye penetrant i method and accepted as clean before proceeding with subsequent layers.

4. First-weld layer is to have a measured .

l delta ferrite content greater than 7.5 FN. t l

. 5. Design thickness includes no allowarice for surface conditioning operations to facilitate UT inspections.

l

6. Design length is that required for structural reinforcement; greater length '

may be required for effective UT inspection.

This is to be determined in the field.

GPCO-180-015, Rev.1, Page 2 of 2 NEG

' ASSOCI AT ES, IN C, ITY B-22

i

= A =!= B -- FLOW 45' MIN - 1 TYP )

U 1

''''''''' 'h!? ' ','h' s $

/

.d\

l /

Elbow Pipe  ;

1 tWELD -

e WELD DVERLAY REPAIR DETAILS FLAW DESIGN DIMENSIONS WELD NUMBER CHARACTERIZATION i A 8 1B31-lRC-28B-15 0.52" 3.35" 3,35" i

Tu PREPARED BY DATE DESCRlril0N dM ~

$//6/po Standard Weld Overlay Repair Desig n for Weld 1B31-lRC-28B-15 CHECKED ST: .. DAIE *

(per NUREG-0313, Revision 2)

Y WSAO JOB NO: PLANT / UNIT REV Georgia Power Plant 3

GPCO-18Q Hatch Unit 1  :  ; e- s- t FILE NO: DW NO: -

xi SHT GPCO-18Q-314 GPCO-18Q-016 1 2 0F B-23

~ ~ - - , - - - - -

l NOTES ,

i i

I

1. Weld overlay material is to be type 308L  ;

or equivalent, with as-deposited delta ,

ferrite content greater than 7.5 FN.

]

2. Component surface is to be examined by dye  !

penetrant method and accepted as clean l prior to overlay application in order to j include the entire deposited overlay thickness in meeting the design thickness i requirement, per NUREG-0313, Revision 2. l

3. In the event that the original component surface does not pass the note 2 require-ments, the first deposited weld layer l is to be examined by dye penetrant 1 method and accepted as clean before proceeding with subsequent layers.

)

4. First weld layer is to have a measured I s delta ferrite content greater than 7.5 FN.

5. Design thickness includes no allowance for surface conditioning operations to '

facilitate UT inspections.

6. Design length is that required for i structural reinforcement; greater length

• i may be required for effective UT inspection.

L This is to be determined in the field.

I GPCO-180-016, Rev.1, Page 2 of 2

?NEGNI?Y

' AS SOCI AT E S, IN C.

B-24

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

APPENDIX C Revised Fracture Mechanics Evaluation-for Unoverlayed Welds k

l' l .

l l

l l'

i l

SIf 90-039, Rev. O C-0  ; .,e -

e > e4 4 l

N l-

p-t tm  ;

pc-CRACK (C) COPYRIGHT 1984, 1988 STRUCTURAL INTEGRITY ASSOCIATES, INC.

SAN JOSE, CA (408)978-8200 VERSION 2.0 Date: 21-Jun-1990 Times 16:46:50.90 STRESS CORROSION CRACK GROWTH ANALYSIS f GPCO-180, WELD 12AR-G-4 INITIAL CRACK SIZEm 0.1390 WALL THICKNESS = 0.6V30 MAX CRACK SIZE FOR SCCG= 0.5544 STRESS CORROSION CRACK GROWTH LAW LAW ID C N Kthres K1C NRC 3.590E-08 2.1610 0.0000 200.0000 L

STRESS COEFFICIENTS CASE ID CO C1 C2 C3 IHSIl0F ~30.7058 -212.1766 1411.8703 -1505.4352 12AR-G-4 19.1400 0.0000 0.0000 0.0000 12BR-A-4 17.4900 0.0000 0.0000 0.0000 12BR-E-4 21.9400 0.0000 0.0000 0.0000 Kman PASE ID SCALE FACTOR

.HS!10F 1.00 12AR-G-4 1.00 TIME PRINT TIME, INCREMENT INCREMENT 50000.0- 25000.0 25000.0 crack model:CIRCUMFERENTIAL CRACK IN CYLINDER (T/R=0.1)

CRACK ---------------STRESS INTENSITY FACTOR----------------

SIZE CASE CASE CASE CASE IHSIlOF 12AR-G-4 12BR-A-4 12BR-E-4 0.0111 -6.625 3.962 3.621 4.542 0.0222. -9.748 5.629 5.144 6.452 0.0333 -12.353 6.925 6.328 7.938 0.0444 -14.686 8.032 7.339 9.207 0.0554 -16.832 9.020 8.242 10.339 0.0665 -18.826 9.924 9.069 11.376 0.0776 -20.800 10.826 9.892 12.409 0.0887 -22.711 11.708 10.698 13.420 e c-1 l l

i pc-CRACK VERSION 2.0 FAGE O.0998 -24.527 12.561 11.478 14.398 0.1109 -26.248 13.391 12.236 15.350 0.1220 -27.873 34.202 12.978 16.280 w 0.1331 -29.402 14.999 13.706 17.193

, 0.1441 -30.912 15.826 14.461 18.141 0.1552 -32.408 16.690 15.252 19.132 0.1663 -33.810 17.553 16.040 20.121 0.1774 -35.113 18.414 16.827 21.108 0.1885 -36.315 19.276 17.614- 22.095 3 0.1996 -37.412 20.138 18.402 23.083  !

0.2107 -38.474 21.046 19.232 24.125 0.2218 ~39.652 22.099 20.194 25.332 0.2328 -40.723 23.163 21.167 26.552 0.2439 -41.685 24.239 22.150 27.785 0.2550 -42.535 25.327 23.144 29.032 0.2661 -43.270 26.426 24.148 30.292 0.2772 -43.887 27.537 25.163 31.565 0.2883 -44.544 28.720 26.244 32.921 0.2994 -45.091 29.916 27.337 34.293 J 0.3105 -45.*s28 31.127 28.443 35.680 '

O.3216 -45.855 32.351 29.562 37.083 0.3326 -46.073 33.588 30.693 38.502 0.3437 -46.183 34.840 31.836 37.936 0.3548 -46.339 36.180 33.061 41.473 0.3659 -46.443 37.562 34.324 43.057 0.3770 -46.447 38.960 35.601 44.659 0.3881 -46.354 40.374 36.893 46.280 0.3992 ~46.168 41.804 38.200 47.920 0.4103 -45.892 43,250. 39.521 49.577 0.4213 -45.492 44.766 40.907 51.315 0.4324 -44.958 46.356 42.359 53.137 0.4435 -44.334 47.963 43.828 54.980 0.4546 -43.626 49.588 45.314 56.843 0.4657 -42.841 51.231 46.815 58.726 0.4768 -41.989 52.892 48.332 60.630 0.4879 -41.082 54.610 49.902 62.598 0.4990 -40.103 56.465 51.597 64.725 0.5100 -39.035 58.340 53.311 66.875 0.5211 -37.889 60.236 55.044 69.048 0.5322 -36.675 62.152 56.794 71.245 0.5433 -35.405 64.088 58.564 73.464 ,

0.5544 -34.093 66.044 60.351 75.706

' TIME KMAX DA/DT DA A A/THK 25000.0 -14.77 0.OOOE+00 0.0000 0.1390 0.201 END OF oc-CRACK l

C-2 l r. ,

E  !

4 -o l

tm oc-CRACK (C) COPYRIGHT 1984, 1988 STRUCTURAL INTEGRITY ASSOCIATES, INC.

SAN JOSE, CA (408)978-8200 VERSION 2.0 i

i Date 21-Jun-1990 Times 16:45:32.52 i STRESS CORROSION CRACK GROWTH ANALYd."o GPCO-18Q, WdLD12BR-A-4 I

I INITIAL CRACK SIZE = 0.1800 l WALL THICKNESS = 0.6930 MAX CRACK SIZE FOR SCCG= 0.5544 l STRESS CORROSION CRACK GROWTH LAW LAW ID C N Kthres K1C NRC 3.590E-08 2.1610 0.0000 200.0000 STRESS COEFFICIENTS CASE ID CC C1 C2 C3  ;

IHSIl0F -30.7050 -212.1766 1411.8703 -1b05 4352 12AR-G-4 19.14CO 0.0000 0.0000 0.0000 12BR-A-4 17.49(0 0.0000 0.0000 0.0000 12BR-E-4 21.9400 0.0000 0.0000 0.0000 Kmax  ;

CASE ID SCALE FACTOR IHSIl0F 1.00 123R-A-4 1.00 TIME PRINT ,

TIME- INCREMENT INCREMENT-50000.0 25000.0 25000.0 crack model:CIRCUMFERENTIAL CRACK IN CYLINDER (T/R=0.1)

CRACK ------------"--STRESS INTENSITY FACTOR----------------

SIZE .' CASE CASE CACE CASE THSIl0F 12AR-G-4 12BR-A-4 12BR-E-4 0.0111 -6.625 3.962 3.621 4.542 0.0222 -9.748 5.629 5.144 6.452 0.0333 -12.353 6.925 6.328 7.938 0.0444 -14.686 8.032 7.339 9.207 i 0.0554- -16.832 9.020 8.242 10.339 0.0665 -18.826 9.924 9.069 11.376 0.0776 -20.800 10.826 9.892 12.409 ,

0.0887 -22.711 11.708 10.698 13.420 ,_ ,

C-3

., e pc-CRACK VERSION 2.0 PAGE O.0998 -24.527 12.561 11.478 14.398 0.1109 -26.248 13.391 12.236 15.350 0.1220 ~27.873 14.202 12.978 16.280 0.1331 -29.402 14.999 13.706' 17.193 0.1441 -30.912 15.826 14.461 18.141  ;

O.1552 -32.408 16.690 15.252 19.132 0.1663 -33.810 17.553 16.040 20.121 i O.1774 -35,113 18.414 16.827 21.108

'O.1885 -36.315 19.276 17.614 22.095 0.1996 -37.412 20.138 18.402 23.083 "

1 0.2107 -38.474 21.046 19.232 24.125 O.2218 -39.652 22.099 20.194 25.332 0.2328 -40.723 23.163 21.167 26.552 0.2439 -41.685 24.239 22.150 27.785 0.2550 -42.535 25.327 23.144 29.032 0.2661 -43.270 26.426 24.148 30.292 0.2772 ~43.887 27.537 25.163 31.565  ;

O.2883 -44.544 28.720 26.244 32.921 <

0.2994 -45.091 29.916 27.337 34.293 0.3105 -45.528 31.127 28.443 35.680 i O.3216 -45.855 32.351 29.562 37.083 0.3326 -46.073 33.588 30.693 38.502 i O.3437 -46.183 34.840 31.836 39.936  !

O.3548 -46.339 36.180 33.061 41.473 0.3659 -46.443 37.562 34.324 43.057 .1 0.3770 -46.447 38.960 35.601 44.659 0.3881 -46.354 AO.374 36.893 46.280 0.3992 -46.168 41.804 38.200 47.920 0.4103 -45.892 43.250 39.521 49.577 0.4213 -45.492 44.766 40.907 51.315 0.4324 -44.958 46.356 42.359 53.137 0.4435 -44.334 47.963 43.828 54.980 0.4546. -43.626 49.588 45.314 56.843 0.4657 -42.841 51.231 46.815 58.726 0.4768 -41.989 52.892 48.332 60.630 0.4879 -41.082 54.610 49.902 62.598 0.4990 -40.103 56.465 51.597 64.725 0.5100 -39.035 58.340 53.311 66.875 0.5211 -37.889 60.236 55.044 69.040

.O.5322 -36.675 62.152 56.794 71.245 0.5433 -35.405 64.088 58.564 73.464 0.5544 -54.093 66.044 60.351 75.706 TIME MMAX DA/DT DA A A/THK 25000.0 -18.38 0.OOCE+00 0.0000 0.1800 0.260 END OF pc-CRACK l

C-4

J- ,

m oc-CRACK (C) COPYRIGHT 1984, 1988 STRUCTURAL INTEGRITY ASSOCIATES, INC.

SAN JOSE, CA (408)978-8200 VERSION 2.0 l.

Date: 21'Jun-1990 -

Times 16:44: 8.65 STRESS CORROSION CRACK GROWTH ANALYSIS GPCO-180, MELD 12BR-E-4 INITIAL CRACK SIZE = 0.1730 WALL THICKNESS = 0.6930 MAX CRACK SIZE FOR SCCG= 0.5544 STRESS CORROSION CRACK GROWTH LAW i LAW ID C N Kthres K1C 1 NRC 3.590E-08 2.1610 0.0000 300.0000 STRESS COEFFICIENTS CASE ID CO C1 C2 C3 IHSIlOF -30.7058 -212.1766 1411.8703 -1505.4352.

12AR-G-4 19 1400 0.0000 0.0000 0.0000 12BR-A-4 17.4900 0.0000 0.0000 0.0000 12BR-E-4 21.9400 0.0000 0.0000 0.0000 Kmax CASE ID SCALE FACTOR IHSIlOF 1.00 12BR-E-4 1.00 TIME PRINT TIME INCREMENT INCREMENT 50000.0 25000.0 25000.0 crack model:CIRCUMFERENTIAL CRACK IN CYLINDER (T/R=0.1)

CRACK ---------------STRESS INTENSITY FACTOR---------------- 4 SIZE CASE CASE CASE CASE- f IHSIlOF 12AR-G-4 12BR-A-4 12BR-E-4 0.0111 -6.625 3.962 3.621 4.542

-0.0222 -9.748 5.629 5.144 6.452 O.0333 ~-12.353 6.925 6.328 7.938 0.0444 -14.686 8.032 7.339 9.207

. .O.0554 -16.832 9.020 8.242 10.339-

'O,0665 -18.826 9.924 9.069 11.376 0.0776 -20.800 10.826 9.892 12.409 0.0887' '.2.711

. 11.708 10.698 13.420 C-5

.- J

- _. . = .

i l

y 4 l

pc-CRACK VERSION 2.0 PAGE O.0998 -24.527' 12.561 11.478 14.398 0.1109 -26.248 13.391 12.236 15.350 0.1220 -27.873 14.202 12.978 16.280 0.1331 -29.402 it. 999 13.706 17.193- 1 0.1441 -30.912 15.826 14.461 18.141

-0.1552 -32.408 16.690 15.252 19.132 0.1663- -33.810 17.553 16.040 20.121 0.1774 -35.113 18.414 16.827 21.108 't 0.1885 -36.315 19.276 17.614 22.095 0.1996 -37.412 20.138 18.402 23.083 0.2107 -38.474 21.046 19.232 24.125

.O.2218 -39.652 22.099 20.J94 25.332 0.2328 -40.723 23.263 21.167 26.352 '

0.2439- -41.685 24.239. 22.150 27.785 O.2550 -42.535 25.327 23.144 29.032  ;

O.2661 -43.270 26.426 24.148 30.292 0.2772: -43.887 27.537 25.163 31.565 0.2883 -44.544 28.720 26.244 32.921 0.2994 -45.091 29.916 27.337 34.293 0.3105 -45.528 31.127 28.443 35.680 0.3216 -45.855- 32.351 29.562- 37.003 0.3326 -46.073 33.588 30.693 38.502 0.3437 -46.183 34.840 31.036 47.936 (

O.3548 ' -46.339 36.180 33.061 41.473 0.3659 -46.443 37.562 34.324 43.057

'O.3770 -46.447 38.940 35.601 44.659 0.3881 -46.354 40.374 36.893 46.280 0.3992 -46.168 41.804 38.200 47.920 0.4103 -45.892 43.250 39.521 49.b77 0.4213 -45.492 44.766 40.907 51.315

• 0.4324 -44.958 46.356 42.359 53.137 O.4435 -44.334 47.963 43.828 54.980 0.4546 -43.626 49.588 45.314 56.843 0.4657 '- 42.841 51.231 46.815 58.726 0.4768 -41.989 52.892 48.332 60.630 0.4879- -41.082 54.610 49.902 62.598 0.4990 -40.103 56.465 51.597 64.725 i

0.5100 -39.035 58.340 53.311 66.875 O.5211 -37.889 60.236 55.044 69.040 0.5322 -36 675' 62.152 56.794 71.245 0.5433 -35.405 64.088 58.564 '73.464

, 0.5544 -34.093 66.044' 60.351 75.706 r.f TIME 'KMAX DA/DT DA A ~A/THK 2b000.0 ~13.88 0.OOOE+00 0.0000 0.1730 0.250 END OF pc-CRACK a

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