ML102440264

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0000-0114-0580-RO-NP, Rev. 0, Limerick Generating Station, Units 1 & 2, Upper Shelf Energy Evaluation for LPCI Nozzle Forging Material
ML102440264
Person / Time
Site: Limerick  
Issue date: 08/31/2010
From:
General Electric Co
To:
Office of Nuclear Reactor Regulation
References
DRF 0000-0114-0544 0000-0114-0580-R0-NP, Rev 0
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ATTACHMENT 3 Limerick Generating Station, Units 1&2 Upper Shelf Energy Evaluation for LPCI Forging Material (non-proprietary version)

GE Hitachi Nuclear Energy 0

HITACHI 0000-0114-0580-RO-N P Revision 0 Class I DRF 0000-0114-0544 August 2010 Non-Proprietary Information Limerick Generating Station, Units 1&2 Upper Shelf Energy Evaluation for LPCI Nozzle Forging Material Copyright 2010 GE-Hitachi Nuclear Energy Americas LLC All Rights Reserved

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information NON-PROPRIETARY NOTICE This is a non-proprietary version of the document 0000-0114-0580, Revision 0, from which the proprietary information has been removed. Portions of the document that have been removed are identified by white space within double square brackets, as shown here ((

)).

IMPORTANT NOTICE REGARDING CONTENTS OF THIS REPORT Please read carefully The information contained in this document is furnished solely for the purpose(s) stated in the transmittal letter. The only undertakings of GEH with respect to information in this document are contained in the contracts between GEH and Exelon Generating Company, and nothing contained in this document shall be construed as changing that contract. The use of this information by anyone for any purpose other than that for which it is intended is not authorized; and with respect to any unauthorized use, GEH makes no representation or warranty, and assumes no liability as to the completeness, accuracy, or usefulness of the information contained in this document.

Copyright 2010, GE-Hitachi Nuclear Energy Americas LLC, All Rights Reserved

000-0114-0580-RO-NP Revision 0 Non-Proprietary Information REVISION CONTROL SHEET Revi sion Date.

I Description 0

August 2010 Initial Issue ii

0000-0114-0580-R0-NP Revision 0 Non-Proprietary Information TABLE OF CONTENTS R EV IS IO N C O N T RO L SH EET........................................................................................................................................

ii A C RO N Y M S & A B B R EV IA TIO N S................................................................................................................................

vi EX EC U T IV E SU M M A RY................................................................................................................................................

vii 1.0 IN T RO D U CT IO N A N D BA C KG RO U N D...............................................................................................

.. 1 1.1 H isto rica l B ackg ro u nd.............................................................................................................................

1 1.2 Limerick Generating Station (LGS) N17 LPCI Nozzle.............................................................

2 1.3 M ethodo logy................................................................................................................................................

2 1.4 LGS W ater Level Instrum entation (W LI) Nozzle......................................................................

3 2.0 SC O PE...................................................................................................................................................................

4 3.0 SU M M A RY O F A N A LYSIS RESU LTS...........................................................................................................

5 4.0 LGS USE EVALUATION FOR THE W LI NOZZLE...............................................................................

6 5.0 LG S R PV & LPC I N O ZZ LE D ATA a nd Ki..................................................................

.................................. 7 5.1 LPC I N ozzle Fo rg ing M ateria l Test D ata...................................................................................

.. 7 5.2 SA 508-2 N ozzle Fo rg ing U S E................................................................................................................

9 5.3 Fluence........................................................................................................................................................

12 5.4 N ozzle Forg ing a nd V essel D im ensio ns................................................................................

.. 12 5.5 Plant-Specific Transients.....................................................................................................................

13 5.6 Kip Evaluation for Flows in Plate vs. LPCI Nozzle Forging.................................................

13 5.7 Kit fo r Flow s in Plate vs. LPC I N ozzle Fo rg ing....................................................................

14 6.0 USE MARGIN EVALUATION METHODOLOGY...............................................................................

16 6.1 A ccepta nce C riteria...............................................................................................................................

16 6.2 C alculatio n of A pplied J-Integ ra l.....................................................................................................

17 6.2.1 Interna l Pressure Lo ad ing..............................................................................................................

17 6.2.2 H e atup/C oo ldow n Lo ad in g...........................................................................................................

17 6.2.3 Eff ective Flaw D epth.........................................................................................................................

18 6.2.4 J-Integ ra l C alculatio n......................................................................................................................

18 7.0 S ELEC T IO N O F M A TERIA L J-R C U RV ES.........................................................................................

.. 19 8.0 EVALUATION OF LEVEL A & B CONDITIONS...............................................................................

21 8.1 Level A a nd B Service Lo ad ings........................................................................................................

2 1 8.2 Level A a nd B C o nd itio ns Ev alu atio n......................................................................................

.. 2 1 9.0 EVALUATION OF LEVEL C & D CONDITIONS................................................................................

27 9.1 Level C Serv ice Lo ad ing.......................................................................................................................

27 9.2 Level C Service Ev aluaotio n..................................................................................................................

28 9.3 Level D Service Lo ad ing.......................................................................................................................

3 1 9.4 Level D Service Ev alu aotio n..................................................................................................................

32 10.0 SU M M A RY & C O N C LU S IO N S....................................................................................................................

3 5 11.0 R EFER EN C ES...................................................................................................................................................

36 APPENDIX A: CMTRS FOR LGS N17 LPCI NOZZLE..................................................................................

38 iii

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information TABLE OF FIGURES Figure 6-1:

Figure 7-1:

Figure 8-1:

Figure 8-2:

Figure 9-1:

Figure 9-2:

Figure 9-3:

Figure 9-4:

Figure 9-5:

Illustration of Ductile Crack Growth Stability Evaluation...........................................

16 LGS LPdI Nozzle Forging J-Integral Resistance Curves..............................................

20 Jo., Criterion Evaluation for Axial Flaw and LGS LPCI Nozzle Forging J-R Curve... 24 Flaw Stability Criterion Evaluation for Axial Flaw with LGS LPCI Nozzle Forging J -R C u rv e..............................................................................................................................................

2 6 Pressure & Temperature Conditions During Improper Start of Cold Recirculation Loop Transient for Limiting Level C Event...............................

28 Jo.1 Evaluation for Level C Condition..................................................................................

30 Crack Growth Stability Criterion Evaluation for Level C Condition.......................

31 Lim iting Level D Tra nsient..............................................................................................................

32 Crack Growth Stability Criterion Evaluation for Level D Condition.......................

34 iv

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information TABLE OF TABLES Table 5-1: LGS Unit 1 LPCI Nozzle Test Data for Heat Q2Q25W.......................................................

7 Table 5-2: LGS Unit 1 LPCI Nozzle Test Data for Heat Q2Q35W.......................................................

8 Table 5-3: LGS Unit 2 LPCI Nozzle Test Data for Heat Q2Q33W.......................................................

9 Table 5-4: A508-Class 2 Material Pre-Irradiated CVN Data.............................................................

10 Table 5-5: Updated Summary A-508 Class 2 Material Upper Shelf Energy Fro m N RC D atabase RV ID................................................................................................................

11 Table 5-6 LGS Vessel and LPCI Nozzle Dim ensions............................................................................

13 Ta b le 5-7 LG S Pa ra m eters.....................................................................................................................................

13 Table 5-8: Calculation of Kip for a 1/4T Corner Flaw in a Nozzle....................................................

15 Table 5-9: Calculation of Kip for a 1/4T Flaw in a Flat Plate.............................................................

15 Table 8-1: Calculated Values of Applied J-Integral for 1.15 x Accumulation Pressure........ 23 Table 8-2: Calculated Values of Applied J-Integral for 1.25 x Accumulation Pressure........ 25 Table 9-1: Calculated Values of Applied J-Integral for Level C Transient..................................

29 Table 9-2: Calculated Values of Applied J-Integral for Level D Transient..................................

33 V

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information ACRONYMS & ABBREVIATIONS

-Short:Ve&si'n~

Definition 1/4T 1/4/ Depth into the Vessel Wall from the Inside Diameter (Clad Is Not Considered)

ASME American Society of Mechanical Engineers ASME Code LGS was fabricated in accordance with the 1968 Edition, including Summer Edition 1969 Addenda.

BWR Boiling Water Reactor BWROG BWR Owners' Group CMTR Certified Material Test Report Cu Copper CVN Charpy V-Notch USE (ft-lbs)

EMA Equivalent Margin Analysis EOL End of License EPRI Electric Power Research Institute ft-lb Foot-pound GE General Electric GEH GE Hitachi Nuclear Energy, LLC GL Generic Letter (originated by the NRC)

J0.1 J-Integral from Applied Loads at a Ductile Crack Growth of 0.1 inch Depth into the Vessel Wall Plus Clad Thickness Japptied J-Integral from Applied Loads (in-lb/in 2)

Jmaterial Material's J-Integral Fracture Resistance J-R Curve (in-lb/in 2)

JR J-Integral Fracture Resistance Curve J-R J-Integral Fracture Resistance ksi psi/lO00 LGS Limerick Generating Station LPCI Low Pressure Coolant Injection n/cm 2 Neutrons/ centimeter squared (measure of fluence)

Ni Nickel NRC United States Nuclear Regulatory Commission (sometimes US NRC) psi Pounds per Square Inch Region B Vessel Region from the Bottom of the Jet Pump to the Bottom of the Feedwater Nozzle RG Regulatory Guide RPV Reactor Pressure Vessel RTNDT Reference Temperature of Nil-Ductility Transition RVID NRC Reactor Vessel Integrity Database (available from nrc.gov)

S Sulphur TPO Thermal Power Optimization USE Upper Shelf Energy WLI Water Level Instrumentation wt%

Weight Percent (Elemental Content) vi

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information EXECUTIVE

SUMMARY

10CFR50 Appendix G states that the reactor pressure vessel (RPV) must maintain upper shelf energy (USE) of no less than 50 ft-lbs throughout its life, unless it is demonstrated in a manner approved by the Director, Office of Nuclear Reactor Regulation, that lower values of USE will provide margins of safety against fracture equivalent to those required by Appendix G of Section XI the ASME Code. The BWR Owners' Group developed a licensing topical report (NEDO-32205-A) on equivalent margin analysis for low USE BWR/2 through BWR/6 RPVs, which was reviewed and approved by the NRC for use by individual utilities.

In their Thermal Power Optimization (TPO) submittal, Limerick (LGS) Units 1&2 assumed a low USE for the Limerick LPCI nozzle forgings based on available Certified Material Test Report (CMTR) data. The data was the result of low temperature Charpy specimen testing that also had low Shear results. In addition, the Charpy energies were further reduced because there was no indication whether the specimens were prepared in the strong or weak direction. In accordance with MTEB 5-2, a Branch Technical Position for Fracture Toughness Requirements that provides a summary and clarification of the requirements of 10CFR50 Appendix G and Appendix H, the results were reduced by a factor of 0.65. The LGS minimum end of license (EOL) USE was reported as 24ft-lbs, less than the 50 ft-lb requirement. Therefore, the Equivalent Margin Analysis (EMA) methodology was used to demonstrate that the reduction to account for embrittlement effects, as defined in Regulatory Guide 1.99, Revision 2 (RG1.99), was within the requirements defined in NEDO-32205-A.

However, the topical report does not provide evidence that the EMA methods for plate are applicable to forging material. Therefore, this report documents a plant-specific evaluation that was conducted to show compliance with the USE requirements.

It is demonstrated that the LGS N17 LPCI nozzles should have an initial USE of 70 ft-lbs or greater, based on a comprehensive review performed by Altran for the Brunswick Nuclear Station. Therefore, considering a maximum of 10.8% decrease as prescribed in RG1.99, the LGS LPCI nozzles will maintain 62.4 ft-lbs at end of license, which provides sufficient margin to the requirements of 10CFR50 Appendix G. To further demonstrate the acceptability of the nozzle USE, a J-R curve evaluation was performed.

This LGS forging material USE evaluation follows essentially the methodology outlined in ASME Code Case N-512-1, Appendix K of ASME Section XI and Regulatory Guide 1.161 (RG1.161). The evaluation shows that the Level A/B Condition is.governing.

Based on the results of this plant-specific evaluation, it is concluded that the LPCI nozzle forgings in the LGS RPV meet the margins of safety against fracture equivalent to those required by Appendix G of Section XI the ASME Code and RG1.161. This conclusion is valid for operation including Thermal Power Optimization.

vii

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information The LGS Water Level Instrumentation (WLI) nozzles are J-weld penetrations in the plate, with a forging fabricated from SB166 material that is less than 2.5 inches thick. Therefore, evaluation for fracture toughness is not required. As a result, the evaluation for the WLI nozzle is based upon the plate material in the shell where the WLI penetrations occur.

Therefore, the application of the topical report is appropriate for the LGS WLI nozzles, and further evaluation is not required.

viii

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information

1.0 INTRODUCTION AND BACKGROUND

This report will demonstrate that the forging material for the LGS N17 LPCI nozzles exhibits sufficient tear resistance and ductile stability for Levels A, B, C, and D operating conditions.

The Upper Shelf Energy (USE) margin evaluation methodology used in this report is consistent with that prescribed in Code Case N-512-1 (Reference 6),Section XI Code Non-Mandatory Appendix K (Reference 7), and (RG1.161) (Reference 8). Although Code Case N-512 (References 5, 6, and 7) were in development at the same time that the topical report (Reference 3) was being developed, and Reference 8 was published later, a review of the methodology used in Reference 3 indicated that in almost all respects, it is consistent with References 6, 7, and 8). If there were any small differences, such as that in the selection of J-R curves, the topical report used a conservative approach. The methodology prescribed in Reference 8 is exclusively followed in this report. An earlier evaluation was performed for the N16 nozzle at Brunswick Steam Electric Plants, Units 1 and 2 (Reference 15), which was accepted by the NRC (Reference 16) and established the applicability of this methodology for nozzle forgings.

The methodologies prescribed in Reference 7, 8, and 9 do not specifically identify that which is applicable to forging materials. It is noted in Reference 7, however, that the equations are applicable to SA508-2 as well as SA302B and SA533B.

Therefore, portions of previous submittals and approvals will be utilized so as not to duplicate, and to take advantage of previous regulatory reviews. The use of the BWROG topical report (Reference 3) clearly defines an NRC-approved J-R curve methodology, including the use of specific transients applicable to BWRs, and is therefore cited throughout this report.

.1.1 Historical Background The nuclear reactor pressure vessels (RPVs) are typically made of low-alloy ferritic steels (e.g.,

SA302B; or SA533, Grade B, Class 1).

They are exposed to high energy neutrons in the beltline region; as a result, the constituent parts (i.e., the plates, forgings, and welds) can experience degradation of material properties: yield and ultimate tensile strengths increase, brittle-to-ductile transition temperature increases, and the upper shelf toughness decreases.

The last two effects are the most important from the point of view of structural margins during operation of an RPV. The impact of low Charpy USE on the LGS RPV integrity analyses is the subject of this report.

10CFR50 Appendix G (Reference 1) states that the RPV must maintain USE of no less than 50 ft-lbs throughout its life, unless it is demonstrated in a manner approved by the Director, Office of Nuclear Reactor Regulation, that lower values of USE will provide margins of safety against fracture equivalent to those required by Appendix G of Section Xl the ASME Code (Reference 2). In September 1992, the Nuclear Regulatory Commission (NRC), in discussing the preliminary review of the responses to Generic Letter 92-01, strongly recommended the equivalent margin analyses (EMA) be performed by the Owners' Group. In response to this, the BWROG developed a licensing topical report on equivalent margin analysis for low USE BWR/2 through BWR/6 vessels (Reference 3) that was reviewed and approved by the NRC (Reference 4). The topical report, which could be referenced by utilities as part of their Page 1 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information licensing basis, can be used to address compliance with the 50 ft-lb requirement.

Appendix B of the topical report presents the steps required to show that the USE requirements presented in the report can be applied to individual BWR plants. The plants always have the option to perform a plant-specific USE margin evaluation.

The topical report followed the methods provided in the then-draft Appendix X of the ASME Code, which has since become Code Case N-512 (Reference 5) and subsequently revised as Code Case N-512-1 (Reference 6). This Code Case was incorporated in the Section Xl Code as Non-Mandatory Appendix K (Reference 7). The NRC staff reviewed the analysis methods in Appendix K and found them to be technically acceptable but not complete with respect to information on the selection of transients, and the selection of material properties. As a result the NRC issued RG1.161 (Reference 8) providing specific guidance on these issues.

1.2 Limerick Generating Station (LGS) N17 LPCI Nozzle At LGS, the LPCI nozzles are included in the beltline region because they will accumulate fluence greater than 1.0e17 n/cm2 by end of license (32 EFPY).

At the time of vessel fabrication, forgings were not included in the beltline region; hence, the available data does not provide sufficient information to determine the upper shelf energy. In lieu of high Shear results, the plant used Charpy values from low temperature tests with correspondingly low Shear. For LGS Units 1 and 2, the minimum Charpy values were a result of tests at -20°F with Shear of only 40%. Because the data was not identified as being in the strong or weak direction, the USE was assumed to be in the strong direction, and was reduced using a factor of 0.65 in accordance with MTEB 5-2 (Reference 9). For LGS Unit 1, the minimum initial USE for the LPCI nozzle was 26.7 ft-lbs; for Unit 2, the minimum initial USE was 28 ft-lbs. The end of license USE values did not meet the minimum required value of 50 ft-lbs defined in 10CFR50 Appendix G. Therefore, a plant-specific evaluation was conducted to show compliance.

As stated above, the LGS data does not demonstrate USE. Therefore, this evaluation uses the Brunswick approach as presented in Reference 15 and accepted by the NRC in Reference 16. Extensive research was performed in Reference 15, resulting in an initial USE of 70 ft-lbs. The NRC database, RVID2, was reviewed; Table 5-5 includes several additional data points that were not included in the corresponding table in Reference 15.

The plant-specific evaluation essentially followed the methodology consistent with the requirements of Section XI Code Case 512-1 (Reference 6), Appendix K (Reference 7), and RG1.161 (Reference 8). Also, the selection of transients was justified in relation to the LGS vessel transients for Levels A through D operating conditions. The most limiting transients were considered for Levels A, B, C, and D, in accordance with the requirements of Section 4 of RG1.161, as discussed in more detail in the following sections.

1.3 Methodology It is noted that neither Appendix K nor RG1.161 specifically identifies methodology to perform these calculations for forgings. However, Section K-4210 of Appendix K states that, Page 2 of 41

000-0114-0580-RO-NP Revision 0 Non-Proprietary Information for SA508-2, it is applicable to use the some properties as for SA302B and SA533B. The applicability of this methodology for nozzle forgings was also established by the NRC acceptance (Reference 16) of the Altran report (Reference 15) prepared for the N16 nozzle at Brunswick Steam Electric Plants, Units 1 and 2.

1.4 LGS Water Level Instrumentation (WLI) Nozzle The LGS Water Level Instrumentation (WLI) nozzles are J-weld penetrations in the plate, with a forging fabricated from SB166 material that is less than 2.5 inches thick. Therefore, evaluation for fracture toughness is not required. As a result, the evaluation for the WLI nozzle is based upon the plate material in the shell where the WLI penetrations occur.

Therefore, the application of the topical report is appropriate for the LGS WLI nozzles, and further evaluation is not required.

Page 3 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information 2.0 SCOPE The objective of the analysis documented in this report is to demonstrate that the LGS RPV forging materials meet the margins of safety against fracture equivalent to those required by 10CFR50 Appendix G. This will be accomplished by demonstrating that the EOL USE exceeds 50 ft-lbs, and further demonstrating, by equivalent margin analysis, that a USE less than 50 ft-lbs maintains the required margin of safety against fracture, thereby meeting the requirements of 10CFR50 Appendix G.

In the LGS Thermal Power Optimization (TPO) submittal, USE EMA methods were applied to both the Water Level Instrumentation (WLI) nozzles and the LPCI nozzles.

It will be demonstrated that the WLI nozzles are appropriately evaluated using EMA methods, and that the LPCI nozzles meet the USE requirements for the SA508-2 materials.

Page 4 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information 3.0

SUMMARY

OF ANALYSIS RESULTS 10CFR50 Appendix G states that the RPV must maintain USE throughout its life of no less than 50 ft-lbs, unless it is demonstrated in a manner approved by the Director, Office of Nuclear Reactor Regulation, that lower values of USE will provide margins of safety against fracture equivalent to those required by Appendix G of Section XI the ASME Code. The BWROG developed a licensing topical report on equivalent margin analysis for low USE BWR/2 through BWR/6 RPVs, which was reviewed and approved by the NRC for use by individual utilities.

At LGS, the plant assumed a low USE for the Limerick RPV LPCI nozzle forgings due to insufficient data. As a result, the initial USE was determined to be less than 50 ft-lbs; hence, the EOL USE value did not meet the minimum required value of 50 ft-lbs. This report documents a plant-specific evaluation that was conducted to show compliance with the USE requirements. Following the Brunswick approach (Reference 15), the minimum resulting end of license USE for LGS Units 1 and 2 is 62.4 ft-lbs. which provides sufficient margin to the requirements of 10CFR50 Appendix G. The applicability of this methodology for nozzle forgings was established by the NRC acceptance (Reference

16) of the Altran report (Reference 15).

This LGS USE evaluation followed essentially the methodology outlined in ASME Code Case N-512-1 (Reference 6),

Appendix K of ASME Section XI (Reference 7),

and RG1.161 (Reference 8). The evaluation showed that the Level A/B Condition was governing.

Based on the results of this plant-specific evaluation, it is concluded that the LPCI nozzle forging material in the LGS RPV meets the margins of safety against fracture equivalent to those required by Appendix G of Section XI the ASME Code. This conclusion is valid for operation at Thermal Power Optimization (TPO) conditions.

The LGS Water Level Instrumentation (WLI) nozzles are J-weld penetrations in the plate, with a forging fabricated from SB166 material that is less than 2.5 inches thick. Therefore, evaluation for fracture toughness is not required. As a result, the evaluation for the WLI nozzle is based upon the plate material in the shell where the WLI nozzles occur. Therefore, the application of the topical report is appropriate for the LGS WLI nozzles, and further evaluation is not required.

Page 5 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information 4.0 LGS USE EVALUATION FOR THE WLI NOZZLE The LGS WLI nozzle forging is fabricated from SB166 and is less than 2.5 inches thick.

Therefore, evaluation for fracture toughness is not required. Instead, the penetration for the WLI nozzle is evaluated considering the plate material and fluence at the location of the penetration. Because the fluence at the penetration is much lower than the maximum for the beltline plates, the WLI nozzle USE is bounded by that for the plate location.

For the WLI nozzle, the limiting plate initial USE was used; this value is 71 ft-lbs reduced by a factor of 0.65 to equal 46.2 ft-lbs. This material is appropriately qualified using the EMA methods defined in Reference 3 because the evaluation is performed for the plate material, and not for the forging. Therefore, the WLI nozzle requires no further evaluation.

Page 6 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information 5.0 LGS RPV & LPCI NOZZLE DATA and K, 5.1 LPCl Nozzle Forging Material Test Data The LGS vessel was purchased to the 1968 Edition of the ASME Boiler & Pressure Vessel Code,Section III, with Addenda up to and including Summer 1969. At that time, requirements for determining USE had not yet been established. The LGS LPCI nozzles did not include sufficient testing to enable determination of USE. The LGS Certified Material Test Reports (CMTRs) are provided in Appendix A and a summary of the data obtained from the CMTRs is shown in Tables 5-1 through 5-3.

Table 5-1: LGS Unit 1 LPCI Nozzle Test Data for Heat Q2Q25W Chem istr,.

%Cu*

%Ni

%S N/A Ladle N/A Check N/A

))_Check

  • As no copper data was reported, the copper content for this material was determined using heats of materials used for beltline nozzles at other plants. The mean from nine (9) nozzles plus one (1) standard deviation was used to obtain a value of 0.18%.

Tensile,Properties at RoomJ Temperature Yield Strength Ultimate Strength Elongation (ksi)

(ksi)

(%)

-Fradc'tu'reTohuOýg~hness Pro'pert Iie s__________

Test Temperature Charpy Impact Test Shear Drop Weight NDTT (OF)

Energies

(%)

(OF)

(ft-lb)

Page 7 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information Table 5-2: LGS Unit 1 LPCI Nozzle Test Data for Heat Q2Q35W

.Che Imistr________

%Cu*

%Ni

%S N/A Ladle N/A Check N/A A Check

  • As no copper data was reported, the copper content for this material was determined using heats of materials used for beltline nozzles at other plants. The mean from nine (9) nozzles plus one (1) standard deviation was used to obtain a value of 0.18%.

Tensile Properties at Ro Ultiemperate re Yield Strength Ultimate Strength Elongation (ksi)

(ksi)

(%)

E[

Fracture Toughnes'sPr*.*p*

erties Test Temperature Charpy Impact Test Shear Drop Weight NDTT (OF)

Energies

(%)

(OF)

(ft-lb)

((

Page 8 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information Table 5-3: LGS Unit 2 LPCI Nozzle Test Data for Heat Q2Q33W Chemistryj,'-

%Cu*

%Ni

%S N/A

((_Ladle N/A Check N/A Check N/A Check N/A

))_Check

  • As no copper data was reported, the copper content for this material was determined using heats of materials used for beltline nozzles at other plants. The mean from nine (9) nozzles plus one (1) standard deviation was used to obtain a value of 0.15%.

,fractur Toaurghness PCr perties Test Temperature Charpy Impact Test Shear Drop Weight NDTT (OF)

Energies

(%)

(OF)

(ft-lb) 5.2 SA508-2 Nozzle Forging USE The 70 ft-lb value of initial USE in the Brunswick report was based on a comprehensive review of available data that included the NRC RVID database. Therefore, this initial USE is Page 9 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information used in this evaluation. The data from Tables 3-3 and 3-4 of Reference 15 are provided in Tables 5-4 and 5-5 below. Table 5-5 has been updated to include additional data currently contained in the NRC database RVID2.

Table 5-4: A508-Class 2 Material Pre-irradiated CVN Data Plant Cho.rpy Test CVN @ 40 0

CVN @ USE Turkey Point 4 L-T 85 130 Turkey Point 4 L-T 55 143 Turkey Point 3 L-T 115 150 Turkey Point 3 L-T 110 165 Watts Bar 1 L-T 65 135 Sequoyah 1 T-L 35 70 Sequoyah 1 L-T 80 120 Sequoyah 2 L-T 90 140 Sequoyah 2 T-L 40 100 Point Beach 2 L-T 90 165 Point Beach 2 L-T 110 180 Oconee 3 T-L 50 110 Oconee 3 L-T 85 155 Oconee 3 T-L 75 140 Oconee 2 L-T 95 145 Oconee 2 T-L 80 130 North Anna 2 T-L 25 75 North Anna 2 L-T 70 125 North Anna 1 T-L 25 90 North Anna 1 L-T 70 130 Kewaunee T-L 125 165 Kewaunee L-T 120 160 Kewaunee T-L 65 145 Kewaunee L-T 70 165 RE Ginna 1 L-T 80 170 RE Ginna 1 L-T 100 185 Page 10 of 41

0000-0114-0580-R0-NP Revision 0 Non-Proprietary Information Table 5-5: Updated Summary A-508 Class 2 Material Upper Shelf Energy From NRC Database RVID Plant

  • -Unirradiated USE d J1Method Arkansas 1 109 Generic Braidwood 1 162 Direct Byron 1 138 Direct Byron 1 138 Direct Byron 1 150 Direct Byron 2 149 Direct Byron 2 127 Direct Byron 2 155 Direct Catawba 1 134 Direct Catawba 1 134 Direct Crystal River 3 109 Generic Davis-Besse 140 Direct Davis-Besse 132 Direct Davis-Besse 122 Direct RE Ginna 117 65%

RE Ginna 114 65%

RE Ginna 91 65%

Kewaunee 92 65%

Kewaunee 97 65%

McGuire 2 97 65%

McGuire 2 100 Direct North Anna 1 74 Surveillance Plate North Anna 1 92 Direct North Anna 1 85 Direct North Anna 2 74 Direct North Anna 2 80 Direct North Anna 2 74 EQ to Forging Oconee 1 109 Generic Oconee 2 133 Direct Oconee 2 109 Generic Oconee 2 138 Direct Oconee 3 109 Generic Oconee 3 144 Direct Oconee 3 112 Direct Point Beach 1 78 65%

Point Beach 2 94 65%

Point Beach 2 78 65%

Page 11 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information Plant Unirradiated USE Method [I]

(ft -lb)

Point Beach 2 117 65%

Sequoyah 1 79 Direct Sequoyah 1 72 Direct Sequoyah 2 100 65%

Sequoyah 2 88 Direct Surry 1 83 65%

Surry 2 104 65%

TMI 1 109 Generic Turkey Point 3 99 65%

Turkey Point 3 93 65%

Turkey Point 3 100 65%

Turkey Point 4 86 65%

Turkey Point 4 88 65%

Turkey Point 4 103 65%

Watts Bar 1 88 65%

Zion 1 87 65%

Zion 2 109 Generic Notes:

[1] Direct: This indicates that the unirradiated USE was from a transverse specimen.

65%: This indicates that the unirradiated USE was 65% of the USE from a longitudinal specimen.

Generic: This indicates that the unirradiated USE was reported by the licensee from other plants with similar materials to the beltline material.

With the update to the data as obtained from RVID2 at the time this report was written, it can be seen that the lowest initial USE is shown to be 72 ft-lbs. However, this report will continue to consider 70 ft-lbs to be consistent with the USE previously accepted by the NRC.

5.3 Fluence The LGS TPO submittal was based upon a license of 40 years, considering 32 EFPY. The peak surface fluence applied in the LGS USE evaluation was 1.9e18 n/cm2; this is representative of a bounding calculation that was performed using the GEH licensing topical report for fluence methodology that was approved by the NRC (Reference 20), consistent with the requirements of Regulatory Guide 1.190. The fluence at the elevation of the LPCI nozzles was determined using an attenuation factor, resulting in a fluence of 2.81e17 n/cm2. The 1/4T fluence was calculated in accordance with RG1.99, Revision 2, resulting in a fluence of 1.9e17 n/cm2.

5.4 Nozzle Forging and Vessel Dimensions The LGS vessel and nozzle geometry information is provided in References 11 and 12, and summarized in Tables 5-6 and 5-7 below.

Page 12 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information Table 5-6 LGS Vessel and LPCI Nozzle Dimensions Parmt Abbreviatio'n

Vaue, Vessel Radius Ri

((

_))

Vessel Thickness tv 6.19 inches Clad Thickness tc~d

((

Nozzle Inner Radius ri Nozzle Corner Radius rc Nozzle Thickness tn Apparent Nozzle Radius rn Hoop Stress S

))

Table 5-7 LGS Parameters Parameter A bbre v iatfion Value Design Pressure P

1250 psig Maximum Temperature T

[_

))

Cooling Rate 100 °F/hr Young's Modulus at 70°F E

27900 ksi Yield Strength @ Room Temperature Sy

((

))

Clad Stress, Emergency Conditions Sclad-emergency 6

ksi Clad Stress, Faulted Conditions Sclod-foulted 16.5 ksi The design pressure was unchanged with the introduction of TPO.

The selection of appropriate transients for various operating conditions is discussed in the later sections of this report.

5.5 Plant-Specific Transients The limiting transients for each level of operating conditions were selected for this evaluation in accordance with Section 4 of RG1.161. The limiting Level A and B condition is the 100°F/hr heatup/cooldown; limiting for Level C is the "Improper Start of a Cold Recirculation Loop"; and limiting for Level D is the "Pipe Rupture and Blowdown". These are discussed in more detail in the following sections.

5.6 Kip Evaluation for Flaws in Plate vs. LPCl Nozzle Forging As shown in Tables 5-8 and 5-9 below, the Kip value for the 1/4T nozzle corner flaw bounds the Kip value for a 6:1 aspect ratio 1/4T flaw in the plate based upon the same internal pressure loading of 1250 psi, increased by a safety factor of 1.1 to equal 1375 psi.

Page 13 of 41

000-0114-0580-RO-NP Revision 0 Non-Proprietary Information Table 5-8 demonstrates the calculation of Kip for a 1/4T nozzle corner flaw.

The methodology is presented similar to that previously performed in Table 6-3 of Reference 15 for Brunswick and accepted by the NRC (Reference 16).

The resulting Kip at 1/4T is

((

)) psi'Iin.

Table 5-9 demonstrates the calculation of Kip for a 1/4T flaw in a flat plate. The methodology presented is that defined in Reference 8, which was previously provided to the NRC in Reference 15 and approved in Reference 16. The resulting Kip is ((

)) psi'Iin.

As the Kip for a nozzle corner flaw bounds that for a flat plate, the applied J-Integral calculations for Kip are factored by the ratio of the nozzle to the plate

[r 1].

5.7 Kit for Flaws in Plate vs. LPCI Nozzle Forging The stress intensity factor for a 1/4T nozzle corner crack with the applied thermal loading of 100°F/hour was calculated during the GEH effort related to addressing the water level instrumentation nozzles. The calculated Ki was less than ((

)) ksi'Iin. On the other hand, the corresponding calculated value of Ki using RG1.161 procedures, for a 1/4 T flaw in the plate is approximately ((

)) ksi'/in (see Kt in Table 8-1). This demonstrates that for the 100°F/hour case, the 1/4T plate flaw solution for Ki using RG1.161 procedures can be conservatively used for the nozzle corner flaw case.

Page 14 of 41

OOOO-0114-0580-RO-NP Revision 0 Non-Proprietary Information Table 5-8: Calculation of Kip for a 1/4T Corner Flaw in a Nozzle

[1 Table 5-9: Calculation of Kip for a 1/4T Flaw in a Flat Plate

((

Page 15 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information 6.0 USE MARGIN EVALUATION METHODOLOGY The USE margin evaluation methodology used in this report is consistent with that prescribed in References 6, 7, and 8. Although References 5, 6, and 7 were in development at the same time that the topical report (Reference 3) was being developed, and Reference 8 was published later, a review of the methodology used in Reference 3 indicated that in almost all respects, it is consistent with References 6, 7, and 8. If there were any small differences, such as that in the selection of J-R curves, the topical report used a conservative approach. The methodology prescribed in Reference 8 is exclusively followed in this report.

The applicability of this methodology for nozzle forgings was established by the NRC acceptance (Reference 16) of the Altran report (Reference 15) prepared for the N16 nozzle at Brunswick Steam Electric Plants, Units 1 and 2.

The acceptance criteria and the equations for the calculation of J applied values are described in this section. The selection of appropriate J-R curves is described in the next section.

6.1 Acceptance Criteria The acceptance criteria for Level A & B Normal/Upset conditions are described as:

Japplied < Jo.1 (1)

(2) aJopplied/aa < aJmateriai/aa, load held constant at Japplied = Jmaterial Equation (2) assures stability below:

under ductile crack growth as demonstrated in Figure 6-1 ao Figure 6-1: Illustration of Ductile Crack Growth Stability Evaluation Page 16 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information Both axial and circumferential flaws are postulated. For all operating conditions, the flaws are considered to be semi-elliptical surface flaws with an aspect ratio of 6:1 surface length to flaw depth. The assumed crack is 11/44 of the thickness of the base metal wall.

The acceptance criteria for Level C conditions are provided in Section 3.1.2 of Reference 3 and are essentially the same as Equations (1) and (2) above. For Level C, however, the postulated flaw depth is 1/10 of the thickness of the base metal wall plus the clad thickness, with total depth < 1.0 inch. A safety factor of 1.0 is considered for applied pressure loading.

For Level D conditions, only the ductile crack growth stability is evaluated. The flaw depth is the same as that for Level C, and the material J-Integral resistance curve is based on best estimate. Level D also uses a safety factor on applied loading equal to 1.0.

6.2 Calculation of Applied J-Integral The calculation of the applied J-Integral consists of three steps:

" Step 1 is to calculate the K, values from pressure and heatup/cooldown loadings; Step 2 is to calculate the effective flaw depth, which includes a plastic zone size correction; and Step 3 is to calculate the J-Integral for small-scale yielding based on this effective flaw depth.

The calculated K, values are in the units of ksi/in.

6.2.1 Internal Pressure Loading For an axial flaw with depth 'a' equal to (0.25t + 0.1 inch), the stress intensity factor from internal pressure, Pa, with a safety factor, SF, on pressure equal to 1.15 using Equation (3) below, obtained from (Reference 8):

KipAxial = (SF) Pa [1 + (Ri/t)] (ira)0°. F, (3)

F1

= 0.982 + 1.006 (a/t)2 For a circumferential flaw with depth 'a' equal to (0.25t + 0.1 inch), the stress intensity factor from internal pressure, pa, with a safety factor, SF, on pressure equal to 1.15 using Equation (4), obtained from (Reference 8):

KipCircum. = (SF) pa [1 + {Ri/(2t)}l (Tra)05 F2 (4)

F2

= 0.885 + 0.233 (a/t) + 0.345 (a/t)2 6.2.2 Heatup/Cooldown Loading For an axial or circumferential flaw with depth 'a' equal to (0.25t + 0.1 inch), the "steady state" (time independent) stress intensity factor from radial thermal gradients is obtained by using Equation (5), obtained from Reference 8:

Page 17 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information Kit

= (CR/1000) t2-5 F3 (5)

F3

= 0.69 + 3.127 (alt) - 7.435 (alt)2 + 3.532 (alt)3 The above equation for Kit is valid for 0 < CR < 100°F/hr.

For the transients in which the heatup/cooldown rates are greater than 100°F/hr, Reference 3 used finite element analysis to determine the stress distribution through the RPV wall and the Ki values were then calculated using the Raju-Newman method as described in Reference 3.

6.2.3 Effective Flaw Depth The effective flaw depth for small-scale yielding, Oe, was based on Equation (6), obtained from Reference 8:

ae = a + {1/(67d}[(Kip + Kitl/cy]2 (6)

The topical report (Reference 3) identifies the yield strength as 69 ksi; the average LGS LPCI nozzle CMTR value of ay for SA508-2 is approximately ((

)) ksi at room temperature. The ASME Code value from the LGS Code of Construction is determined to be ((

)) ksi at

((

)) (Reference 19). The Code value at operating temperature was scaled by the Code value at room temperature (70 0F) and the measured room temperature value from the CMTRs. Therefore, cry of approximately ((

)) was used in this evaluation.

6.2.4 J-Integral Calculation The J-Integral from the K, values was calculated using Equation (7), obtained from (Reference 8):

Japplied = 1000 (K'ip + K'it)2/E' (7) where the K'i values are stress intensity factors based on effective flaw depth and E' is E/(i-v 2). The value of v was taken as 0.3 and is consistent with Reference 3; the value of E was determined to be 27900 ksi at room temperature, obtained from the ASME Code for SA508-2 material. The units of J are in-lb/in 2.

Page 18 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information 7.0 SELECTION OF MATERIAL J-R CURVES The generic J-Integral fracture resistance curve equation is given as Equation (8), obtained from Reference 8:

JR

= (MF) {C1 (Aa)C2 exp [C3 (Aa)C4]}

(8)

Forging materials are not discussed in Reference 8; therefore, Section 3.3 (Reactor Pressure Vessel Base (Plate) Materials) of Reference 8 is used to calculate the values of various constants in the preceding equation. Section 3.3 of Reference 8 provides different equations based upon the Sulphur (S) wt% content of the materials being evaluated. The LGS CMTRs (see Appendix A for the CMTRs or Tables 5-1 through 5-3 for a summary of the pertinent data) were reviewed; it was determined that the maximum S content is ((

)) wt%.

Therefore, Section 3.3.1 (High-Toughness Model for S < 0.018 wt%) of Reference 8 is used.

For analyses addressing Service Levels A, B, and C, the factor MF was set to 0.749 as defined in Section 3.3.1 of Reference 8. For analyses addressing Service Level D, the value of MF was set to 1.0. The mathematical expressions for other constants are given by Equations (9) through (12), obtained from Reference 8:

C1

= exp [-2.44 + 1.13 In (CVN) - 0.00277T]

(9)

C2

= 0.077 + 0.116 In C1 (10)

C3

= -0.0812 - 0.0092 In C1 (11)

C4

= -0.409 (12)

The term 'CVN' is the Charpy USE. As indicated above, the EOL Charpy USE for the LGS LPCI nozzles is 62.4 ft-lbs. This value was used in calculating the value of constant C1. The normal operating temperature for region B (that contains the beltline region) of the vessel is specified as ((

)) (References 17 and 18); for power re-rate and TPO this temperature was revised to ((

)) (Reference 19). Therefore, this value was used in calculating the value of constant C1.

The calculated J-Integral resistance curves for the various operating conditions are shown in Figure 7-1 below.

Page 19 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information

((

Figure 7-1: LGS LPCI Nozzle Forging J-Integral Resistance Curves Page 20 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information 8.0 EVALUATION OF LEVEL A & B CONDITIONS Key steps in this evaluation are the calculation of the applied J-Integral and the flaw stability evaluation.

8.1 Level A and B Service Loadings The two loadings to be considered are internal pressure and thermal heatup/cooldown rates.

The Level A and B heatup/cooldown rates for the LGS RPV are specified in the associated reactor thermal cycle diagram (Reference 18) amended by the TPO certified design specification (Reference 19); the TPO specification bounds the power re-rate modifications.

The topical report (Reference 3) also analyzed an additional transient identified as "Loss of Feedwater Pumps" that is specified for BWR/6 standard plants in their RPV thermal cycle drawing. However, the analysis in the topical report showed that the 100°F/hr case was still bounding compared to this transient. The LGS plant-specific thermal cycle diagram was reviewed; it was determined that the heatup/cooldown case is bounded by the evaluation presented in the topical report.

The difference between the RPV geometry considered in the topical report (R= 126.7 inches and t= 6.19 inches) and the LGS RPV geometry (R=((

)) inches and t= 6.19 inches) is less than 1% and thus was considered insignificant in terms of the calculated thermal transient stress. Therefore, the conclusion reached in Reference 3 was also determined to be valid for the LGS case and therefore, only the 100°F/hr case was considered in this evaluation.

The specified design pressure for the LGS RPV is 1250 psi, defined in Reference 19.

Consistent with the NRC-approved topical report, the accumulation pressure is 1.1 times the design pressure and is, thus, equal to 1375 psi. The internal pressure value used in the Jo.,

criterion is 1.15 times the accumulation pressure (i.e., 1375

  • 1.15 or 1581 psi). Similarly, the internal pressure value used in the flaw stability criterion is 1.25 times the accumulation pressure or 1719 psi.

The LGS RPV wall thickness in the beltline region is 6.19 inches. RG1.161 states that, for Levels A and B, the evaluation is to postulate a semi-elliptical surface flaw with an a/t = 0.25 and with an aspect ratio of 6:1 surface length to flaw depth. Clad thickness is not required for this calculation. Therefore, the postulated 1/4T flaw has a depth of (6.19

  • 0.25) or 1.55 inches.

8.2 Level A and B Conditions Evaluation Table 8-1 below shows the calculated values of the applied J-Integral for 1.15 accumulation pressure at several crack depths beginning with the 1/4T depth. The calculations for the axial flaw are shown first, followed by those for the circumferential flaw. For the Jo., criterion, the applied J-Integral values at a = 1.65 inches are relevant. A review of this table indicates Page 21 of 41

000-0114-0580-RO-NP Revision 0 Non-Proprietary Information that the applied J-Integral values for the axial flaw case bound those for the circumferential flaw case. Therefore, the Jo.1 criterion check was conducted only for the axial flaw case.

Figure 8-1 shows a comparison between the calculated applied J-Integral value for the axial flaw and the LPCI nozzle J-R curve. It is seen that the Jo., criterion is satisfied for the limiting case of an axial flaw.

Page 22 of 41

000-0114-0580-RO-NP Revision 0 Non-Proprietary Information Table 8-1: Calculated Values of Applied J-Integral for 1.15 x Accumulation Pressure

((

Page 23 of 41

000-0114-0580-RO-NP Revision 0 Non-Proprietary Information

((I Figure 8-1: Jo. Criterion Evaluation for Axial Flaw and LGS LPCI Nozzle Forging J-R Curve Table 8-2 shows the calculated values of applied J-Integral for 1.25 accumulation pressure at several crack depths beginning with 1/4T depth. The calculations are shown for both the axial and the circumferential flaws. However, a review of this table indicates that the axial flaw case is governing. Figure 8-2 shows the plot of the applied J-Integral curve and the LPCI nozzle material J-R curve. Flaw stability at a given applied load is assured when the slope of the applied J-Integral curve is less than the slope of the material J-R curve at the point on the J-R curve where the two curves intersect (see Figure 6-1). It is seen that the stability criterion is satisfied with the limiting EOL USE of 62.4 ft-lbs for the LGS LPCI nozzle forgings. (Note: In the stability evaluation, the J applied at Aa = 0.1 inch is not a concern; only the slope of the J applied curve is of importance.)

Page 24 of 41

000-0114-0580-RO-NP Revision 0 Non-Proprietary Information Table 8-2: Calculated Values of Applied J-Integral for 1.25 x Accumulation Pressure Page 25 of 41

000-0114-0580-RO-NP Revision 0 Non-Proprietary Information

((

Figure 8-2: Flaw Stability Criterion Evaluation for Axial Flaw with LGS LPCI Nozzle Forging J-R Curve Page 26 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information 9.0 EVALUATION OF LEVEL C & D CONDITIONS The postulated flaw depth for the evaluation of Level C and D loadings is one-tenth the base metal wall thickness, plus the clad thickness, but with total depth not to exceed 1.0 inch. The plate thickness in the beltline region is 6.19 inches. The nominal thickness of the clad is

[

f))inch. Therefore, the postulated crack depth is (6.19

  • 0.1 + ((

))) or ((

inch.

9.1 Level C Service Loading The LGS RPV thermal cycle drawing (Reference 18) amended by Reference 19 specifies Level C events; the TPO specification bounds the power re-rate modifications. The topical report (Reference 3) used an RPV thermal cycle drawing to select a limiting Level C transient (or event). It was determined that for the BWR/3-6 product lines, the "Improper Start of a Cold Recirculation Loop" transient is the most limiting Level C transient. Figure 9-1 shows this transient, which is identified as Transient 26 in the LGS vessel thermal cycle diagram (Reference 18) (Transient 24 in Reference 3), amended by Reference 19. (Note that the pressure shown in Figure 9-1 specifies 1050 psig. The TPO pressure is ((

)) psig; as the difference is less than 1%, the evaluation at 1050 psig would have an insignificant effect, and therefore remains applicable to the LGS evaluation.) Since the geometry differences between the LGS RPV and the RPV geometry analyzed in the topical report were minor (as previously discussed), the K, values for Transient 26 calculated in the topical report were also used in this evaluation. This meant using the same Kt fit coefficients as shown in Table 6-1b of the topical report. The LGS plant-specific thermal cycle diagram was reviewed; it was determined that the Level C event defined in References 18 and 19 is bounded by the evaluation presented in the topical report.

Section 6.1.3 of Reference 3 discusses the calculation method for the K, values due to cladding. The same technical approach and clad stress were used in this report.

Page 27 of 41

000-0114-0580-RO-NP Revision 0 Non-Proprietary Information Emergency Condition 600 550 52 500 450 400 350 -

P 300 -28 250 26 sec 1100 Io I

toso

s. 1050

_____0 1000 0.

Figure 9-1: Pressure & Temperature Conditions During Improper Start of Cold Recirculation Loop Transient for Limiting Level C Event 9.2 Level C Service Evaluation Table 9-1 shows the calculated values of the Level C condition applied J-Integral for axial and circumferential flaws. Since the internal pressure did not change during the thermal transient (see Figure 9-1), only one set of applied J-Integral calculations (shown in Table 9-1) was performed to evaluate the Jo., and the flaw stability criteria. As expected, the axial flaw case is governing. The material J-R curve for the Level C condition is the same as that for the Level A and B conditions.

The Jo.1 criterion and the flaw stability evaluations are graphically shown in Figures 9-2 and 9-3, respectively. it is seen that both the criteria are satisfied.

Page 28 of 41

000-0114-0580-RO-NP Revision 0 Non-Proprietary Information Table 9-1: Calculated Values of Applied J-Integral for Level C Transient

((l Page 29 of 41

O000-0114-0580-RO-NP Revision 0 Non-Proprietary Information Figure 9-2: Jo.1 Evaluation for Level C Condition Page 30 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information 1[

1]

Figure 9-3: Crack Growth Stability Criterion Evaluation for Level C Condition 9.3 Level D Service Loading The limiting Level D transient is the "Pipe Rupture and Blowdown" event, identified as Transient 29 in the LGS vessel thermal cycle diagram (Reference 18) (Transient 27 in Reference 3), amended by Reference 19; the TPO specification bounds the power re-rate modifications. The pressure temperature profile is shown in Figure 9-4. Two differences are that the LGS pressure at the beginning of the transient is ((

)) psig, and at the end of the transient is ((

)) psig (as opposed to the 20 psig shown in Figure 9-4); the plant-specific pressure of ((

)) psig at the end of the event has been used in the LGS evaluation as shown in Table 9-2. The difference between 1050 psig and ((

)) psig is less than 1%

and any impact to the evaluation is considered to be insignificant. Since the geometry differences between the LGS RPV and the RPV geometry analyzed in the topical report (Reference 3) are minor (as previously discussed), the K, values for Transient 29 calculated in the topical report were also used in this evaluation. Section 6.2.2 of Reference 3 describes the fracture mechanics methodology used in the derivation of the K, values. The Kt fit coefficients shown in Table 6-2 of the topical report were therefore also used in this evaluation. The LGS plant-specific thermal cycle diagram was reviewed; it was determined Page 31 of 41

000-0114-0580-RO-NP Revision 0 Non-Proprietary Information that the Level D event defined presented in the topical report.

in References 18 and 19 is bounded by the evaluation Faulted Condition ja.

I-0I-0.

w V

I-0.

600 550 500 450 400 350-300 250 1200 1000 800 600 400 200 0

F L

Figure 9-4: Limiting Level D Transient 9.4 Level D Service Evaluation Table 9-2 shows the calculated values of the Level D condition applied J-Integral for axial and circumferential flaws. The internal pressure at the end of the transient was used in the applied J-Integral calculations. As expected, the axial flaw case is governing. The material J-R curve for Level D conditions is based on the margin factor (MF) of 1.0 as specified in Reference 8. Figure 9-5 graphically shows the flaw stability evaluation. It is seen that the ductile flaw crack growth stability criterion is satisfied.

Page 32 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information Table 9-2: Calculated Values of Applied J-Integral for Level D Transient Page 33 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information Figure 9-5: Crack Growth Stability Criterion Evaluation for Level D Condition Page 34 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information 10.0

SUMMARY

&CONCLUSIONS 10CFR50 Appendix G states that the RPV must maintain USE of no less than 50 ft-lbs throughout its life, unless it is demonstrated in a manner approved by the Director, Office of Nuclear Reactor Regulation, that lower values of USE will provide margins of safety against fracture equivalent to those required by Appendix G of Section XI the ASME Code.

For the LGS TPO evaluation, the plant assumed a lower bound USE for the LPCI nozzle forgings based on low temperature Charpy tests with low Shear results. When the material was evaluated using RG1.99, Revision 2 (Reference 13), the minimum predicted EOL USE value (24 ft-lbs) did not meet the required value of 50 ft-lbs defined in Reference 1.

Consequently, the USE EMA methodology defined in Reference 3 was applied. However, the topical report (Reference 3) does not specifically identify that forging materials were included in the statistical calculations. Therefore, the calculation in this report documents a plant-specific evaluation that was conducted to show compliance with the USE requirements using RG1.161 (Reference 8) and ASME Appendix K (Reference 7). It is noted that RG1.161 does not address forging materials; however, Appendix K, Section K-4210 indicates that it is applicable to SA508-2 materials.

It is therefore deemed acceptable and reasonable to evaluate using the plate material methodology from References 7 and 8 to represent the LGS LPCI nozzle forging materials. In addition, the applicability of this methodology for nozzle forgings was established by the NRC acceptance (Reference 16) of the Altran report (Reference 15) prepared for the N16 nozzle at Brunswick Steam Electric Plants, Units 1 and 2.

This LGS LPCI nozzle forging USE evaluation followed essentially the methodology outlined in ASME Code Case N-512-1 (Reference 6), Appendix K of ASME Section XI (Reference 7), and RG1.161 (Reference 8). The evaluation shows that the Level A and B Condition is governing.

The predicted LGS plant-specific EOL USE value of 62.4 ft-lbs was obtained using the methods defined in RG1.99 and an initial USE of 70 ft-lbs from Reference 15, approved by the NRC in Reference 16.

Based on the results of this plant-specific evaluation, it is concluded that the LPCI nozzle forgings in the LGS RPV meet the margins of safety against fracture equivalent to those required by Appendix G of Section Xl the ASME Code.

The LGS Water Level Instrumentation (WLI) nozzles are J-weld penetrations in the plate, with a forging fabricated from SB166 material that is less than 2.5 inches thick. Therefore, evaluation for fracture toughness is not required. As a result, the evaluation for the WLI nozzle is based upon the plate material in the shell where the WLI nozzles occur. Therefore, the application of the topical report is appropriate for the LGS WLI nozzles, and further evaluation is not required.

Page 35 of 41

O000-0114-0580-RO-NP Revision 0 Non-Proprietary Information

11.0 REFERENCES

1. "Fracture Toughness Requirements", Appendix G to Part 50 of Title 10, the Code of Federal Regulations, July 1983.
2. "Fracture Toughness Criteria for Protection Against Failure", Appendix G to Section X1 of the ASME Boiler & Pressure Vessel Code, 2004 Edition.
3. Mehta, H.S., et al., "10CFR50 Appendix G Equivalent Margin Analysis for Low Upper Shelf Energy in BWR/2 Through BWR/6 Vessels", NEDO-32205-A, Revision 1, February 1994.
4. James T. Wiggins (US NRC) to Lesley A. England (Gulf States), "Acceptance for Referencing of Topical Report NEDO-32205, Revision 1, '10CFR50 Appendix G Equivalent Margin Analysis for Low Upper Shelf Energy in BWR/2 through BWR/6 Vessels"', December 08, 1993.
5. Code Case N-512, "Assessment of Reactor Vessels with Low Upper Shelf Charpy Impact Energy Levels",Section XI, Division 1 Code, February 12, 1993.
6. Code Case N-512-1, "Assessment of Reactor Vessels with Low Upper Shelf Charpy Impact Energy Levels",Section XI, Division 1 Code, August 24, 1995.
7. American Society of Mechanical Engineers, "Assessment of Reactor Vessels with Low Upper Shelf Charpy Impact Energy Levels," Appendix K, A93, pp. 482.1-482.15,Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components", 1992 Edition, 1993 Addenda, New York, December 1993.
8. USNRC, "Evaluation of Reactor Pressure Vessels with Charpy Upper-Shelf Energy Less Than 50 ft-lb", Regulatory Guide 1.161, June 1995.
9. Branch Technical Position - MTEB 5-2, "Fracture Toughness Requirements", Revision 1, July 1981.
10. Not Used
11. LU Tilly, "Pressure-Temperature Curves for PECO Energy Company Limerick Unit 1",

GE-NE-B11-00836-00-01-R1, Revision 1, May 2009. (-GEH Proprietary Information-)

12. U Tilly, "Pressure-Temperature Curves for PECO Energy Company Limerick Unit 2",

GE-NE-B11-00836-00-02-R1, Revision 1, May 2009. (-GEH Proprietary Information-)

13. USNRC, "Radiation Embrittlement of Reactor Vessel Materials", Regulatory Guide 1.99, Revision 2, May 1988.
14. Not Used
15. PK Shah, "N-16 Nozzles Upper Shelf Energy Evaluation", Technical Report No. 96124-TR-01, Revision 0, Altran, Boston, MA, December 1996.
16. NRC to CP&L (Brunswick), "Evaluation of the January 17, 1992 Operating Transient at the Brunswick Steam Electric Plant, Unit 1, and Evaluation of Carolina Power & Light Company's Equivalent Margins Analysis of the N-16A/B Instrument Nozzles at the Brunswick Steam Electric Plant, Units 1 and 2 (TAC Nos. MA0399/400)", October 16, 1998.
17. Limerick Nozzle Thermal Cycle Diagram, GE Drawing No. 158B8827. (-GEH Proprietary Information-)
18. Limerick Vessel Thermal Cycle Diagram, GE Drawing No. 761E708. (-GEH Proprietary Information-)

Page 36 of 41

000-0114-0580-RO-NP Revision 0 Non-Proprietary Information

19. GEH Document 26A7844, Certified Design Specification for Limerick 1 & 2 "Reactor Vessel - Thermal Power Optimization", Revision 0. (-GEH Proprietary Information-)
20. H.N. Berkow (US NRC) to G.B. Stramback (GE), "Final Safety Evaluation Regarding Removal of Methodology Limitations for NEDC-32983P-A,

'General Electric Methodology for Reactor Pressure Vessel Fast Neutron Flux Evaluations' (TAC No.

MC3788)", November 17, 2005.

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000-0114-0580-RO-NP Revision 0 Non-Proprietary Information APPENDIX A: CMTRS FOR LGS N17 LPCI NOZZLE Unit 1 Heats:

Q2Q25W Q2Q35W Unit 2 Heat:

Q2Q33W Page 38 of 41

000-0114-0580-RO-NP Revision 0 Non-Proprietary Information LGS Unit 1 Heat Q2Q25W Page 39 of 41

0000-0114-0580-RO-NP Revision 0 Non-Proprietary Information LGS Unit 1 Heat Q2Q35W

((

Page 40 of 41

000-0114-0580-RO-NP Revision 0 Non-Proprietary Information LGS Unit 2 Heat Q2Q33W Page 41 of 41

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