ML13009A375

Enclosure B to L-12-444, Calculation No. 32-9195651-000, Equivalent Margins Assessment of Davis-Besse Transition Welds for 52 EFPY - Non-Proprietary.

ML13009A375
Person / Time
Site:	Davis Besse
Issue date:	12/12/2012
From:	Killian D AREVA, FirstEnergy Nuclear Operating Co
To:	Office of Nuclear Reactor Regulation
References
L-12-444 32-9195651-000
Download: ML13009A375 (72)

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Enclosure B Davis-Besse Nuclear Power Station, Unit No. 1 (Davis-Besse)

Letter L-12-444 Calculation No. 32-9195651-000, "Equivalent Margins Assessment of Davis-Besse Transition Welds for 52 EFPY -

Non-Proprietary" 71 pages follow

For Information Only 0402-01-FOl (Rev. 016, 03/31/2011)

A CALCULATION

SUMMARY

SHEET (CSS)

AREVA Document No. 32 - 9195651 - 000 Safety Related: 1K Yes 0 No Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non-Title Proprietary PURPOSE AND

SUMMARY

OF RESULTS:

The purpose of the present analysis is to demonstrate that the reactor vessel thickness transition welds at Davis Besse Unit 1 satisfy the requirements of Appendix Kto Section Xl of the ASME Boiler and Pressure Vessel Code for low upper-shelf Charpy impact energy levels at 52 effective full power years of plant operation. The two Davis Besse circumferential transition welds are located just below weld WF-232/233 between the upper shell and nozzle belt forgings where the vessel wall thickness changes from [ ] to [ ] and at weld WF-232/233 between the lower shell and Dutchman forgings where the thickness changes from [ ] to I I.

AREVA NP Inc. proprietary information in the document are indicated by pairs of braces" [ ] "

Summary of Results The requirements of Section X1, Appendix K are satisfied for all applicable loading conditions, as summarized below for the limiting transition weld (circumferential weld WF-232/233 between the upper shell and nozzle belt forgings).

For Levels A and B Service Loadings:

1. The applied J-integral with a factor of safety of 1.15 on pressure is less than the J-integral of the material at a flaw extension of 0.10 in. by a margin of 3.58.

2. Flaw extensions are ductile and stable with a factor of safety of 1.25 on pressure.

For Levels C and D Service Loadings:

1. The applied J-integral with a factor of safety of 1.0 on loading is less than the J-integral of the material at a flaw extension of 0.10 in. by a margin of 3.15.

2. Flaw extensions are ductile and stable with a factor of safety of 1.0 on loading.

3. The total flaw depth after stable flaw extension is less than 75% of the vessel wall thickness and the remaining ligament is sufficient to preclude tensile instability by a large margin.

THE DOCUMENT CONTAINS ASSUMPTIONS THAT SHALL BE THE FOLLOWING COMPUTER CODES HAVE BEEN USED IN THIS DOCUMENT: VERIFIED PRIOR TO USE CODENERSION/REV CODENERSION/REV YE ANSYS 12.1ZN S1.NYES Page 1 of 71

For Information Only A 0402-01-F01 (Rev. 016, 03/31/2011)

Document No. 32-9195651-000 AREVA NON PROPRIETARY Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Review Method: 0 Design Review (Detailed Check)

LI Alternate Calculation Signature Block PIR/A Name and Title and Pages/Sections (printed or typed) Signature LPILR Date PreparedlReviewedlApproved D. E. Killian Technical p I 2- All Consultant A. D. Nana Engineer T. M. Wiger Unit Manager A 1-1.All Note: P/R/A designates Preparer (P), Reviewer (R), Approver (A);

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For Information Only A 0402-01-F01 (Rev. 016, 03/31/2011)

AREVA Document No. 32-9195651-000 NON - PROPRIETARY Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Record of Revision Revision PageslSections/Paragraphs No. Changed Brief Description / Change Authorization 000 All Original release

___ t ________ I ______________

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For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table of Contents Page SIGNATURE BLOCK ................................................................................................................................ 2 RECO RD OF REVISIO N .......................................................................................................................... 3 LIST OF TABLES ..................................................................................................................................... 6 LIST OF FIG URES ................................................................................................................................... 7 1.0 INTRODUCTIO N ........................................................................................................................... 8 2.0 ACCEPTANCE CRITERIA .......................................................................................................... 10 2.1 Levels A and B Service Loadings (K-2200) .............................................................................. 10 2.2 Levels C Service Loadings (K-2300) ........................................................................................ 10 2.3 Levels D Service Loadings (K-2400) ........................................................................................ 11 3.0 ANALYTICAL METHODO LOGY ............................................................................................ 12 3.1 Procedure for Evaluating Levels A and B Service Loadings .................................................... 12 3.2 Procedure for Evaluating Levels C and D Service Loadings .................................................... 14 3.3 Stress Intensity Factor Solution for Cladded Vessels ................................................................ 15 3.4 Temperature Range for Upper-Shelf Fracture Toughness Evaluations ................................... 16 4.0 ASSUM PTIO NS .......................................................................................................................... 19 4.1 Unverified Assumptions .............................................................................................................. 19 4.2 Justified Assumptions ..................................................................................................................... 19 4.3 Modeling Simplifications ........................................................................................................... 19 5.0 MATERIAL PROPERTIES AND REACTOR VESSEL DESIGN DATA .................................. 20 5.1 J-Integral Resistance Model for Mn-Mo-Ni/Linde 80 Welds ....................................................... 20 5.2 Material Properties for Weld Material ........................................................................................ 21 5.3 Reactor Vessel Design Data .................................................................................................... 26 5.4 J-Integral Resistance Values for Weld Material ......................................................................... 30 6.0 APPLIED LOADS ........................................................................................................................ 31 6.1 Levels A and B Service Loadings ............................................................................................ 31 6.2 Levels C and D Service Loadings ............................................................................................. 31 Page 4

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table of Contents (continued)

Page 7.0 COMPUTER USAGE .................................................................................................................. 34 7 .1 Hardw are/S oftwa re ......................................................................................................................... 34 7.2 InstallationNalidation Test ........................................................................................................ 34 7 .3 C o m pute r F ile s ............................................................................................................................... 36 8.0 EVALUATION FOR LEVELS A AND B SERVICE LOADINGS ............................................. 43 9.0 EVALUATION FOR LEVELS C AND D SERVICE LOADINGS ............................................ 52 10.0

SUMMARY

OF RESULTS .................................................................................................... 69 11.0 R E F E R E NC E S ............................................................................................................................ 70 Page 5

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary List of Tables Page Table 5-1: Material Data for DB-1 Reactor Vessel Transition Welds at 52 EFPY with MUR ............ 22 Table 5-2: Mechanical Properties for SA-508 Class 2 Forgings and Associated Weldments .......... 23 Table 5-3: Material Properties for Base Metal .................................................................................. 24 Table 5-4: Materials Properties for Cladding .................................................................................... 25 Table 5-5: Representative Values of J-Integral Resistance ............................................................. 30 T able 7-1: Test R esults .......................................................................................................................... 35 Table 8-1: Flaw Evaluation for Levels A & B Service Loadings - Upper Weld ................................ 44 Table 8-2: Flaw Evaluation for Levels A & B Service Loadings - Lower Weld ................................ 45 Table 8-3: J-Integral vs. Flaw Extension for Levels A & B Service Loadings - Upper Weld ............ 46 Table 8-4: J-Integral vs. Flaw Extension for Levels A & B Service Loadings - Lower Weld ............ 47 Table 8-5: J-R Data for Evaluation of Levels A & B Service Loadings - Upper Weld ...................... 48 Table 8-6: J-R Data for Evaluation of Levels A & B Service Loadings - Lower Weld ...................... 49 Table 9-1: J-Integral vs. Flaw Extension for Hot Leg Loss of Coolant Accident- Upper Weld ...... 55 Table 9-2: J-Integral vs. Flaw Extension for Hot Leg Loss of Coolant Accident - Lower Weld ...... 56 Table 9-3: J-R Curve Data for Evaluation of Levels C & D Service Loadings - Upper Weld ........... 57 Table 9-4: J-R Curve Data for Evaluation of Levels C & D Service Loadings - Lower Weld ........... 58 Table 9-5: Tensile Instability Check for Level D Service Loadings - Upper Weld ........................... 59 Table 9-6: Tensile Instability Check for Level D Service Loadings - Lower Weld ............................ 60 Page 6

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary List of Figures Page Figure 1-1: Reactor Vessel Materials for Davis Besse Unit 1 ............................................................ 9 Figure 3-1: Finite Element Model of Upper Transition Region .......................................................... 17 Figure 3-2: Finite Element Model of Lower Transition Region .......................................................... 18 Figure 5-1: Upper T ransition Region ................................................................................................. 27 Figure 5-2: Upper Transition Weld ................................................................................................. . . 28 Figure 5-3: Low er Transition Weld ................................................................................................... 29 Figure 6-1: Transient Descriptions for Level C Service Loadings .................................................... 32 Figure 6-2: Transient Descriptions for Level D Service Loadings .................................................... 33 Figure 8-1: J-Integral vs. Flaw Extension for Levels A & B Service Loadings - U pper Weld ........... 50 Figure 8-2: J-Integral vs. Flaw Extension for Levels A & B Service Loadings - Lower Weld ........... 51 Figure 9-1: KI vs. Crack Tip Temperature for Levels C & D Service Loadings - Upper Weld .......... 61 Figure 9-2: KI vs. Crack Tip Temperature for Levels C & D Service Loadings - Lower Weld .......... 62 Figure 9-3: KI vs. Crack Tip Temperature for Various Flaw Depths - Upper Weld .......................... 63 Figure 9-4: KI vs. Crack Tip Temperature for Various Flaw Depths - Lower Weld .......................... 64 Figure 9-5: J-Integral vs. Flaw Extension for Levels C & D Service Loadings - Upper Weld ........... 65 Figure 9-6: J-Integral vs. Flaw Extension for Levels C & D Service Loadings - Lower Weld ........... 66 Figure 9-7: J-Integral vs. a/t for Levels C & D Service Loadings - Upper Weld ............................... 67 Figure 9-8: J-Integral vs. a/t for Levels C & D Service Loadings - Lower Weld ............................... 68 Page 7

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary

1.0 INTRODUCTION

The purpose of this fracture mechanics analysis is to perform an equivalent margins assessment of welds in the Davis Besse Unit 1 (DB-1) reactor vessel that are at or near transitions in vessel thickness.

Stresses are higher at these "transition welds" compared to those in simple cylindrical sections of the vessel due to the presence of local structural discontinuities at these locations. Reactor vessel beltline materials exhibiting upper-shelf Charpy impact energy levels below 50 ft-lbs are required by 10 CFR Part 50, Appendix G [1] to be analyzed to demonstrate by an equivalent margins assessment (EMA) that the margins of safety against fracture are equivalent to those required by Appendix G to Section XI of the ASME Code [2]. Appendix G to 10 CFR Part 50 requires that an equivalent margins assessment use the latest edition and addenda of the ASME Code incorporated by reference to paragraph (b)(2) of 10 CFR Part 50.55a [3] at the time the analysis is submitted to the NRC for review. The latest edition of Section XI referenced by the current version of 10 CFR Part 50.55a(b)(2) is the 2007 Edition with the 2008 Addenda. The Davis Besse reactor vessel materials are identified in Figure 1-1. In order to bound all test data on material properties, FirstEnergy has directed that an equivalent margins assessment be performed for the transition welds of the reactor vessel. This low upper-shelf toughness EMA will be based on the projected reactor vessel neutron fluence at 52 effective full power years (EFPY) of operation and a Measurement Uncertainty Recapture (MUR) rated core power of 2819 Mwt.

The present EMA addresses ASME Levels A, B, C, and D Service Loadings. For Levels A and B Service Loadings, the upper-shelf fracture toughness of each transition weld is evaluated for the design cooldown rate, general evaluation procedures, and acceptance criteria of Appendix K to Section XI of the ASME Code [2]. The evaluation procedures and acceptance criteria of Appendix K are also used to evaluate the transition welds for Davis Besse specific Levels C and D Service Loadings. Since the one-dimensional stress intensity factor formulations of Appendix K are directly applicable to only simple cylindrical shells, alternative solutions are developed from published solutions for circumferential surface flaws using location specific temperatures and stresses determined by two-dimensional finite element analysis of the transition regions [4].

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For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary RV ID NOZZLE BELT WF-232 (91 ID)

WF-233 (911 OD)

UPPER SHELL A -

=- UPPER SHELL WF-182-1

=- LOWER SHELL LOWER SHELL WF-232 (121 ID)

WF-233 (881 OD)

DUTCHMAN Figure Reactor Vessel Materials for Davis Besse Unit 1 P-1:

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For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary 2.0 ACCEPTANCE CRITERIA Acceptance criteria for the assessment of reactor vessels with low upper shelf Charpy impact levels are prescribed in Article K-2000 of Appendix K to the ASME Code,Section XI [2]. These criteria are summarized below as they pertain to the evaluation of reactor vessel weld metals.

2.1 Levels A and B Service Loadings (K-2200)

(a) When evaluating adequacy of the upper shelf toughness for the weld material for Levels A and B Service Loadings, an interior semi-elliptical surface flaw with a depth one-quarter of the wall thickness and a length six times the depth shall be postulated, with the flaw's major axis oriented along the weld of concern and the flaw plane oriented in the radial direction. Two criteria shall be satisfied:

(1) The applied J-integral evaluated at a pressure 1.15 times the accumulation pressure (P,) as defined in the plant specific Overpressure Protection Report, with a factor of safety of 1.0 on thermal loading for the plant specific heatup and cooldown conditions, shall be less than the J-integral of the material at a ductile flaw extension of 0.10 in.

(2) Flaw extensions at pressures up to 1.25 times the accumulation pressure (Pa) shall be ductile and stable, using a factor of safety of 1.0 on thermal loading for the plant specific heatup and cooldown conditions.

(b) The J-integral resistance versus flaw extension curve shall be a conservative representation for the vessel material under evaluation.

2.2 Levels C Service Loadings (K-2300)

(a) When evaluating the adequacy of the upper shelf toughness for the weld material for Level C Service Loadings, interior semi-elliptical surface flaws with depths up to one-tenth of the base metal wall thickness, plus the cladding thickness, with total depths not exceeding 1.0 inch, and a surface length six times the depth, shall be postulated, with the flaw's major axis oriented along the weld of concern, and the flaw plane oriented in the radial direction. Flaws of various depths, ranging up to the maximum postulated depth, shall be analyzed to determine the most limiting flaw depth. Two criteria shall be satisfied:

(1) The applied J-integral shall be less than the J-integral of the material at a ductile flaw extension of 0.10 in., using a factor of safety of 1.0 on loading.

(2) Flaw extensions shall be ductile and stable, using a factor of safety of 1.0 on loading.

(b) The J-integral resistance versus flaw extension curve shall be a conservative representation for the vessel material under evaluation.

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For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary 2.3 Levels D Service Loadings (K-2400)

(a) When evaluating adequacy of the upper shelf toughness for Level D Service Loadings, flaws as specified for Level C Service Loadings shall be postulated, and toughness properties for the corresponding orientation shall be used. Flaws of various depths, ranging up to the maximum postulated depth, shall be analyzed to determine the most limiting flaw depth. Flaw extensions shall be ductile and stable, using a factor of safety of 1.0 on loading.

(b) The J-integral resistance versus flaw extension curve shall be a best estimate representation for the vessel material under evaluation.

(c) The extent of stable flaw extension shall be less than or equal to 75% of the vessel wall thickness, and the remaining ligament shall not be subject to tensile instability.

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For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary 3.0 ANALYTICAL METHODOLOGY Upper-shelf toughness is evaluated using the fracture mechanics analytical procedures of Section XI, Appendix K [2], augmented as necessary to incorporate location specific stresses determined by two-dimensional finite element analysis and stress intensity factors calculated from an influence coefficient based solution for circumferential surface flaws.

3.1 Procedure for Evaluating Levels A and B Service Loadings Stress intensity factors for Levels A and B Service Loadings are based on the Chapuliot, Lacire, and Le Delliou solution [5] for internal semi-elliptical circumferential surface flaws, using an effective flaw depth to account for small scale yielding at the crack tip and computing the applied J-integral per Appendix K, Article K-4210 [2]. The adequacy of the upper-shelf toughness and flaw stability is then evaluated according to Articles K-4220 and K-4310, respectively. The overall evaluation procedure is outlined below.

(1) For a circumferential flaw of depth 'a', the stress intensity factor due to internal pressure is calculated with a safety factor (SF) on pressure using the following influence coefficient solution:

Kip= (SF) Ao0 +Ali,1( + A 2 i2 ( + A 3 i3 -j 7,j 0* *0.80 where the axial finite element stresses through the base metal are fitted by the third-order polynomial A=Ao +A1 )+A2<K +A 3 ,

and 'x' is the radial distance to the inside surface. The 'i' influence coefficients are determined from Reference [5] for a 6:1 semi-elliptical surface flaw with a depth equal to one-quarter of the thickness of the base metal.

(2) For a circumferential flaw of depth 'a', the stress intensity factor due to thermal stress is calculated from

[(a) (a )2 (a )3]V (a),,

Kit= A 0 i0 +Ali, +A 2 i2 - +A 3 i3 - *-A, 0 - *0.80 where the terms are as defined in (1) above.

(3) The effective flaw depth for small scale yielding, a., is calculated using the following:

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For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AR EVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary

)[Kip Kt ae =a+

(4) For a circumferential flaw of depth 'ae', the stress intensity factor due to internal pressure is Kip = (SF) Aoi0 + Ali1 + A2121 +A 3i 3 , 0< <ae 0.80 where the influence coefficients are updated for the new flaw depth as a function of a.t.

(5) For a circumferential flaw of depth 'a,', the stress intensity factor due to thermal stress is K;t= A 0 i0 +Aii1j(!j +A2i2(T-J + A 3i3 ]a ' 0*< <!K 0.80 (6) The J-integral due to applied loads for small scale yielding is calculated using the following:

J1 = 1000 Kp+IKt)

E where E'- E (7) Evaluation of upper-shelf toughness at a flaw extension of 0.10 inch is performed for a flaw depth, a = 0.25t + 0.10 in.

using SF = 1.15 P=Pa where Pa is the accumulation pressure for Levels A and B Service Loadings, such that J1 < Jo.1 and J1 = the applied J-integral for a safety factor of 1.15 on pressure, and a safety factor of 1.0 on thermal loading Page 13

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Jo. 1 = the J-integral resistance at a ductile flaw extension of 0.10 in.

(8) Evaluation of flaw stability is performed through use of a crack driving force diagram procedure by comparing the slopes of the applied J-integral curve and the material J-integral resistance curve, or J-R curve. The applied J-integral is calculated for a series of flaw depths corresponding to increasing amounts of ductile flaw extension. The applied pressure is the accumulation pressure for Levels A and B Service Loadings, Pa, and the safety factor (SF) on pressure is 1.25. Flaw stability at a given applied load is verified by ensuring that the slope of the applied J-integral curve is less than the slope of the J-R curve at the point on the J-R curve w here the two curves intersect.

3.2 Procedure for Evaluating Levels C and D Service Loadings Levels C and D Service Loadings are evaluated following the general procedure outlined in Article K-5000 [2] utilizing a combination of two-dimensional finite element stress analysis and influence coefficient stress intensity factor solutions for cladded vessels. The only Level C Service Loading (emergency condition) is the Stuck Open Turbine Bypass Valve (transient 17B in the DB-1 reactor coolant system functional specification [6]. The Level D Service Loadings (faulted conditions) are the Steam Line Failure (functional specification transient 16) and (Hot Leg) Loss of Coolant (functional specification transient 21). Pressure and temperature time histories are presented in Figure 6-1 for the emergency condition transient and in Figure 6-2 for the faulted condition transients. The evaluation of Levels C and D Service Loadings considers pressure and thermal loads (including the effects of cladding), deadweight load, and residual stresses from welding. Finite element analysis is used to obtain pressure and thermal stresses through the cladding and base metal portions of the vessel wall.

Deadweight stresses are calculated by hand and welding induced stress intensity factors are obtained from nomograms used in the one-dimensional PCRIT code [7] for thermal shock analysis.

The evaluation is performed as follows:

(1) Utilize the finite element models depicted in Figure 3-1 and Figure 3-2 to determine stresses in the upper and lower thickness transition regions of the reactor vessel. These figures illustrate the base metal, cladding, and circumferential weld portions of the models.

(2) Calculate stress intensity factors for a semi-elliptical depth flaw depths up to 1/10 the base metal wall thickness (with total flaw depth through cladding and base metal not to exceed 1.0 inch), as a function of time due to internal pressure and thermal gradients with a factor of safety of 1.0 on loading. The critical time in the transient occurs at that point where the stress intensity factor most closely approaches the upper-shelf toughness curve. The stress intensity factor solution is presented in Section 3.3.

(3) At the critical transient time, develop a crack driving force diagram with the applied J-integral and J-R curves plotted as a function of flaw extension. The adequacy of the upper-shelf toughness is evaluated by comparing the applied J-integral with the J-R curve at a flaw extension of 0.10 in. Flaw stability is assessed by examining the slopes of the applied J-integral and J-R curves at the poi nts of intersection.

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For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary (4) As required by Article K-5300(b) [2], demonstrate that the total flaw depth after stable flaw extension is less than or equal to 75% of the vessel wall thickness and the remaining ligament is not subject to tensile instability.

3.3 Stress Intensity Factor Solution for Cladded Vessels In order to account for differential thermal expansion and the discontinuity in stress at the cladding/base metal interface, stress intensity factors are calculated using a solution developed at Oak Ridge National Laboratory for cladded vessels [8]. Although this solution was developed for longitudinal flaws, it is conservative to use it for circumferential flaws since circumferential flaws experience greater constraint than longitudinal flaws. The Oak Ridge solution is implemented as follows:

(1) For a continuous-function stress distribution through the cladding and base metal obtained by fitting a 3rd-order polynomial to the base metal stresses (the base metal stresses are "extrapolated" into the cladding by the continuous stress function),

Kb3 K(a) = N7ra L Bj KO (a/ t) 0.01<_ ( t*a) < 0.50 j=0 where 'a' is the flaw depth measured from the cladding wetted surface and the axial finite element stresses through the base metal are fitted by the third-order polynomial 3

G(U) =L-' Bj(u/a)j, j=0 and 'u' is the radial distance from the cladding wetted surface. The Kib influence coefficients are determined from Reference [8] for a 6:1 semi-elliptical surface flaw as a function of flaw depth.

(2) For a linear stress distribution through the cladding obtained by subtracting the extrapolated stresses from the actual stresses in the cladding, 1

Kc (a)I =4**a~~j=0 L Cj K9 (a/t) 0.01_< (t 0.50 500 where 'a' is the flaw depth measured from the cladding wetted surface and the axial finite element stresses through the cladding are expressed as 1

G(u) = " Cj(u/r)j ,

j=0 and 'r' is the thickness of the cladding. The Kjc influence coefficients are determined from Reference [8] for a 6:1 semi-elliptical surface flaw as a function of flaw depth.

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For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AR EVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary (3) The total stress intensity factor is then, K, (a)= Kb(a)+Kc(a) 3.4 Temperature Range for Upper-S helf Fracture Toughness Evaluations Upper-shelf fracture toughness is determined through use of Charpy V-notch impact energy versus temperature plots by noting the temperature above which the Charpy energy remains on a plateau, maintaining a relatively high constant energy level. Similarly, fracture toughness can be addressed in three different regions on the temperature scale, i.e. a lower-shelf toughness region, a transition region, and an upper-shelf toughness region. Fracture toughness of reactor vessel steel and associated weld metals are conservatively predicted by the ASME initiation toughness curve, Kic, in lower-shelf and transition regions. In the upper-shelf region, the upper-shelf toughness curve, Ko, is derived from the upper-shelf J-integral resistance model described in Section 5.1. The upper-shelf toughness then becomes a function of fluence, copper content, temperature, and fracture specimen size. When upper-shelf toughness is plotted versus temperature, a plateau-like curve develops that decreases slightly with increasing temperature. Since the present analysis addresses the low upper-shelf fracture toughness issue, only the upper-shelf temperature range, which begins at the intersection of the K1, and upper-shelf toughness curves, is considered.

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For Information Only Document No. 32-9195651-000 A

AREVA NON - PROPRIETARY Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary AN Figure 3-1: Finite Element Model of Upper Transition Region Page 17

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary AN Figure 3-2: Finite Element Model of Lower Transition Region Page 18

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary 4.0 ASSUMPTIONS This section discusses assumptions and modeling simplifications applicable to the present analysis.

4.1 Unverified Assumptions This analysis contains no assumptions that must be verified prior to use on safety-related work.

4.2 Justified Assumptions

1) As commonly assumed for pressure vessel analysis, Type 304 (18Cr-8Ni) stainless steel material is used to represent the austenitic cladding.

2) The standard deviation for the initial RTNDT, a1 , is assumed to be the same for the inside WF-232 weld materials as for the outside WF-233 weld materials.

3) Since irradiated values of yield and tensile strengths are not available for weld material WF-233, values for the similar weld material WF-232 will be used instead.

4) Based on previous thermal analysis of reactor vessel downcomer regions, 3500 BTU/hr-ft*-F 2 is a reasonable value of the heat transfer (film) coefficient to use on the wetted surface of the cladding.

4.3 Modeling Simplifications No modeling simplifications were necessary for the present analysis. The two-dimensional thermal and structural finite element models used to obtain temperatures and stresses are considered to be accurate representations of the thickness transition regions of the reactor vessel.

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For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary 5.0 MATERIAL PROPERTIES AND REACTOR VESSEL DESIGN DATA An upper-shelf fracture toughness material model is presented in this section, as well as mechanical properties for the weld material and reactor vessel design data.

5.1 J-Integral Resistance Model for Mn-Mo-NilLinde 80 Welds A model for the J-integral resistance versus crack extension curve (J-R curve) was derived specifically for Mn-Mo-Ni/Linde 80 weld materials for use in analyzing low upper-shelf energy materials [9]. Using a modified power law to represent the J-R curve, the mean value of the J-integral is given by:

A lower bound (-2Se) J-R curve is obtained by multiplying J-integrals from the mean J-R curve by

[ ] [9]. It has been demonstrated [10] that for fluence values up to at least 2.0 x 1019 n/cm 2 that a typical lower bound J-R curve is a conservative representation of toughness for reactor vessel weld materials, as required by Appendix K [2] for Levels A, B, and C Service Loadings. The best estimate representation of toughness required for Level D Service Loadings is provided by the mean J-R curve.

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For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary 5.2 Material Properties for Weld Material Table 5-1 identifies and lists various material properties for the DB-1 reactor vessel transition welds.

The DB-1 reactor vessel shells are fabricated from A-508 Class 2 forging material [11] which is identical to SA-508 Class 2 material that is identified in the current ASME Codes as SA-508 Grade 2 Class 1 material. Temperature-dependent yield and tensile strengths are developed for the welds in Table 5-2 by multiplying room temperature values from surveillance specimen data [12] by the ratio of the ASME Code [13] base metal value at temperature to the value at room temperature. Material properties needed for the thermal and stress analyses are listed in Table 5-3 and Table 5-4 for the base metal and cladding components, respectively.

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For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table 5-1: Material Data for DB-1 Reactor Vessel Transition Welds at 52 EFPY with MUR Location Weld Through Weld Copper Nickel Chemistry Initial Initial Cladding/ Irradiated Irradiated ID Wall Orient. Content Content Factor RTNDT Standard Base Metal Yield Tensile Extent (wt-%) (wt-%) (0F) (°F) Deviation, Fluence 2 (1018 Strength Strength Wl n/cm ) at 550°F at 550°F

(°F) (ksi) (ksi)

[14] [14] [14] [14] [14] [14] [14] [14] [15] [121 [12]

NBF/USF WF-232 ID 9% C 0.18 0.62 157.3 -47.6 17.2* 2.270 82.3* 97.5*

WF-233 OD 91% C 0.21 0.65 172.3 -47.6 17.2 2.270 82.3 97.5 LSF/DF WF-232 ID 12% C 0.18 0.62 157.3 -5.0 19.7* 0.228 82.3* 97.5*

WF-233 OD 88% C 0.21 0.65 172.3 -5.0 19.7 0.228 82.3 97.5

• Not available - use value for WF-233 Page 22

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table 5-2: Mechanical Properties for SA-508 Class 2 Forgings and Associated Weldments Yield Strength, Sy (ksi) Ultimate Tensile Strength, Su (ksi)

Temp.

(OF) ASME Weld Weld ASME Weld Weld Code WF-232 WF-233 Code WF-232 WF-233

[13] [Note 1] [Note 1] [13] [Note 1] [Note 1]

70 50.0 69.9 69.9 80.0 86.1 86.1 100 50.0 69.9 69.9 80.0 86.1 86.1 200 47.0 65.7 65.7 80.0 86.1 86.1 300 45.5 63.6 63.6 80.0 86.1 86.1 400 44.2 61.7 61.7 80.0 86.1 86.1 500 43.2 60.4 60.4 80.0 86.1 86.1 600 42.1 58.8 58.8 80.0 86.1 86.1 700 40.7 56.9 56.9 80.0 86.1 86.1 Note 1. Derived by multiplying room temperature values from Reference [12] by the ratio of the ASME Code base metal value at temperature to the value at room temperature.

Page 23

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table 5-3: Material Properties for Base Metal Component Reactor Vessel Forgings Material SA-508 Class 2 [11](1)

Composition 3/4Ni-1/2Mo-1/3Cr-V Temperature E v cx p C k 3

(OF) (psi) (in/in/°F) (lb/in ) (Btu/Ib-OF) (Btu/hr-in-OF) 70 27.8x10 6 0.3 6.4x106 0.2841 0.105 1.975 100 27.6x10 6 0.3 6.5x106 0.2839 0.107 1.967 150 27.4x10 6 0.3 6.6x106 0.2835 0.110 1.958 200 27.1x10 6 0.3 6.7x106 0.2831 0.113 1.958 250 26.9x10 6 0.3 6.8x106 0.2828 0.116 1.950 6

300 26.7x10 0.3 6.9x10-6 0.2823 0.120 1.950 350 26.4x10 6 0.3 7.0x10-6 0.2820 0.123 1.942 400 26.1x10 6 0.3 7.1x10-6 0.2817 0.125 1.925 450 25.9x10 6 0.3 7.2x10-6 0.2813 0.129 1.917 500 25.7x10 6 0.3 7.3x106 0.2809 0.131 1.892 550 25.5x10 6 0.3 7.3x106 0.2805 0.134 1.875 600 25.2x10 6 0.3 7.4x10- 0.2802 0.136 1.850 650 24.9x10 6 0.3 7.5x106 0.2797 0.139 1.825 700 24.6x10 6 0.3 7.6x106 0.2794 0.142 1.800 Reference [13] Typical [13] [16] Calc.(2) [13]

(1)The current ASME Code designation for this material is SA-508 Grade 2 Class 1.

(2) Specific Heat = (Thermal Conductivity [13]) / [Density [16] * (Thermal Diffusivity [13])]

Page 24 I

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table 5-4: Materials Properties for Cladding Component Reactor Vessel Cladding Material Type 304 Stainless Steel (assumed)

Composition 18Cr-8Ni Temperature E v ( p C k 3

(OF) (psi) (in/in/°F) (lb/in ) (Btu/Ib-°F) (Btu/hr-in-°F) 70 28.3x10 6 0.3 8.5x106 0.2864 0.115 0.717 100 28.1x10 6 0.3 8.6x108 0.2862 0.116 0.725 150 27.8x106 0.3 8.8x10-6 0.2857 0.118 0.750 200 27.5x10 6 0.3 8.9x10 6 0.2853 0.121 0.775 6 6 250 27.3x10 0.3 9.1x10 0.2848 0.123 0.800 6

300 27.0x10 0.3 9.2x10-6 0.2844 0.125 0.817 6

350 26.7x10 0.3 9.4x10-6 0.2840 0.127 0.842 6

400 26.4x10 0.3 9.5x10-6 0.2836 0.129 0.867 6

450 26.2xl 0 0.3 9.6xl 0s 0.2832 0.130 0.883 6

500 25.9x10 0.3 9.7x10 6 0.2827 0.132 0.908 6

550 25.6x10 0.3 9.8x10- 0.2823 0.132 0.925 6 6 600 25.3x10 0.3 9.8x10 0.2818 0.133 0.942 6 6 650 25.1x10 0.3 9.9x10 0.2814 0.135 0.967 6 6 700 24.8x10 0.3 10.0x10- 0.2810 0.136 0.983 Reference [13] Typical [13] [16] Calc.(Y) [13]

(1)Specific Heat = (Thermal Conductivity [13]) / [Density [16] * (Thermal Diffusivity [13])]

Page 25

For Information Only Document No. 32-9195651-000 A

AREVA NON - PROPRIETARY Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary 5.3 Reactor Vessel Design Data Pertinent design data for the thickness transition regions of the DB-1 reactor vessel are listed below.

Additional geometrical data are provided in Figu re 5-1, Figure 5-2, and Figure 5-3.

Note: These fabrication drawings do not show cladding inside of the welds which is added after assembly of the vessel.

Page 26

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Propnetay WF-232 (9/ ID)

WF-233 (91X GD)

Reference:

[19]

Figure 5-1: Upper Transition Region Page 27

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AR EVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary WF-232 (9/ ID)

WF-233 (91X OD)

Reference:

[19], [18], [21]

Figure 5-2: Upper Transition Weld Page 28

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary WF-232 (12/ ID)

WF-233 (88/ OD)

References:

[18], [20], [22]

Figure 5-3: Lower Transition Weld Page 29

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AR EVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary 5.4 J-Integral Resistance Values for Weld Material Values of J-integral resistance from the upper-shelf toughness model of Section 5.1 are dependent on the temperature and fluence at the crack tip location, the copper content of the weld material, and the size (thickness) of the fracture specimen.

Fluence at the crack tip is determined using the attenuation equation from Regulatory Guide 1.99, Revision 2 [23]:

4 Ot = surf (e-024x) where 2

ot = attentuated fluence at crack tip, n/cm Osur = fluence at inside surface, n/cm 2 x = depth into the vessel wall, in.

A basic reference point for determining equivalent margins is the J-integral resistance of the low upper-shelf toughness material at a ductile flaw extension of 0.10 in., J 0.1. Values of J0.1 at normal operating conditions are presented in Table 5-5 for each weld at flaw depths of t/4 for Levels A and B Service Loadings and ama,, where t is the weld thickness and am,, is the maximum flaw depth to be considered for Levels C and D Service Loadings. For steady state conditions, the J-integral resistance values are calculated at a crack tip temperature equal to the reactor inlet coolant temperature.

Table 5-5: Representative Values of J-Integral Resistance Location Flaw Depth, Flaw Total Depth Fluence J-Integral Resistance, Jo.1 a (in.) Extension, x = a + Aa o Lower Aa (in.) (in.) (1018 ncm 2) Mean Bound (lb/in) (lb/in)

NBF/USF tuTw/ 4 = 2.1406 0.1 2.2406 1.326 990 [ J NBF/USF arnx* = 0.8125 0.1 0.9125 1.824 981 [ ]

LSF/DF tLTW/ 4 = 1.3785 0.1 1.4785 0.160 1044 [ ]

LSF/DF am=,** = 0.5514 0.1 0.6514 0.195 1067 [ ]

• lesser of turw/10 and 1.0 inch minus the cladding thickness

• • lesser of tLTrw/10 and 1.0 inch minus the cladding thickness Page 30

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary 6.0 APPLIED LOADS The Levels A and B Service Loadings required by Appendix K are an accumulation pressure (internal pressure load) and a cooldown transient (thermal load). Since Levels C and D Service Loadings are not specified by the Code, the present EMA analyzes each transient classified as either an emergency or faulted condition event i n the DB-1 reactor coolant sy stem functional specification [6].

6.1 Levels A and B Service Loadings Per Article K-1300 of Appendix K [2], the accumulation pressure used for flaw evaluations should not exceed 1.1 times the design pressure. Using 2500 psi as the design pressure, the accumulation pressure is 2750 psi. A conservative cooldown rate of 100 OF/hour (from 560°F to 70°F in 4.9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />) is used to represent the Levels A and B Service Loadings. This is the maximum attainable cooldown rate at DB-1 [6] and the maximum cooldown rate required by Appendix K.

6.2 Levels C and D Service Loadings As discussed in Section 3.2, the Levels C and D Service Loadings are the stuck open turbine bypass valve emergency condition and the steam line failure (break) and hot leg loss of coolant (accident) faulted conditions. Pressure and temperature time-histories for these transients are plotted in Figure 6-1 and Figure 6-2. The transient thermal analysis for each loading was of sufficient duration to capture the peak value of stress intensity factor over time.

Page 31

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AR EVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary 17111 -Stuck Open Turbine Bypass Valve 570 3000 565 560 2500 555 2000 550 Teffemue 1500 545 540-PeueJ 1000 535-0 530-525i1 Time (min)

Figure 6-1: Transient Descriptions for Level C Service Loadings Page 32

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AR EVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary 16 - Steam Line Break 2500 2000 1500 1000 500 0

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Time (min) 21 - Hot Leg Loss of Coolant Accident 700 2500 600 Termperatue 2000 500 400 1500 300 1000 200 500 100 0 0 0.0 0.1 0.2 0.3 0.4 0.5 Time (min)

Figure 6-2: Transient Descriptions for Level D Service Loadings Page 33

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary 7.0 COMPUTER USAGE This section describes the computer resources, software testing, and stored computer files.

7.1 Hardware/Software The following computer resources were used in the present analysis.

1. Computer: Dell Precision T5500 Workstation - Tag#IS N Cl H2NL1

2. Computer processor: Intel Xeon CPU E5504 @ 2.00GHz

3. Computer memory: 3.43 GB RAM @ 2.00GHz

4. Computer operating system: Microsoft Windows XP Professional Version 2002 Service Pack 3

5. Software: ANSYS 12.1 7.2 InstallationNalidation Test Two verification problems were used to test key features of the ANSYS finite element computer program [4] used in the current stress analysis. The current analysis utilizes the two-dimensional axisymmetric 8-node PLANE77 thermal and PLANE183 structural solid elements. Verification test case VM1 12 performs a transient thermal analysis to calculate temperatures in a spherical body where heat loss is due to convective heat transfer boundary conditions. Test case VM32 calculates steady state thermal stresses in a long cylinder.

ANSYS verification case VM1 12 tests the two-dimensional 8-node thermal element PLANE77 element under transient conditions. The standard ANSYS verification test case VM32 exercises static thermal and stress analysis features of the two-dimensional 4-node PLANE55 and PLANE42 elements, respectively, using a long thick-walled cylinder subjected to a linear through-wall temperature gradient.

This test case has been modified (VM32MOD) by increasing the mesh refinement and changing the thermal element type from the 4-node PLANE55 element to the 8-node PLANE77 element and the structural element type from the 4-node PLANE42 to the 8-node PLANE183 element.

Test results:

1. Name of person running test: D. E. Killian

2. Date of test: 08-08-12

3. Results and Acceptability: See Table 7-1. Input and result files are located in ColdStor as listed in Section 7.3.

Page 34

For Information Only Document No. 32-9195651-000 A

AREVA NON - PROPRIETARY Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table 7-1: Test Results Verification Problem VMl 12 Cooling of a Spherical Body - Temperature at 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> File: vm112.vrt

---

VM112 RESULTS COMPARISON---------------

I TARGET I ANSYS I RATIO TEMP. (F) 28.0 28 . 98 1.035 Verification Problem VM32MOD Steady State Thermal Stresses in a Long Cylinder File: vm32mod.vrt

---

VM32MOD RESULTS COMPARISON----------------

I TARGET I ANSYS I RATIO PLANE77 THERMAL ANALYSIS:

T (C) X=.1875 in -1.00000 -1.00000 1.000 T (C) X=.2788 in -0.67037 -0.67039 1.000 T (C) X=.6250 in 0.00000 0.00000 0.000 PLANE183 STATIC ANALYSIS:

A_STS psi X=.187 420.42 444.98 1.058 T_STS psi X=.187 420.42 443.90 1.056 A_STS psi X=.625 -194.58 -200.28 1.029 T_STS psi X=.625 -194.58 -200.28 1.029 Page 35

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary 7.3 Computer Files The computer files listed below are stored in the AR EVA ColdStor repository in the directory

"\cold\General-Access\32\32-9000000\32-9184568-000\of ficial".

ANSYS Models ColdStor ColdStor File Name Description Storage Storage Checksum Date Time UTThermalModel.db Upper transition 08-29-12 13:05:56 53577 thermal model LTThermalModel.db Lower transition 08-29-12 13:06:32 08713 thermal model UTStressModel.db Upper transition 08-29-12 13:05:55 20551 stress model LTStress_Model.db Lower transition 08-29-12 13:06:30 06727 stress model ThermoMechProp.mac Upper transition 08-29-12 13:05:53 16093 material properties LTThermoMechProp.m ac Lower transition 08-29-12 13:06:32 14178 material properties ANSYS Input Files ColdStor ColdStor File Name Description Storage Storage Checksum Date Time Upper transition UTPressureStress.inp stress analysis for 08-29-12 13:07:55 12657 pressure Upper transition UTCooldownThermal.inp thermal analysis for 08-29-12 13:07:53 18295 cooldown Upper transition UTCooldownStress.inp stress analysis for 08-29-12 13:07:53 27260 cooldown Upper transition UTSOTBVThermal.inp thermal analysis for 08-29-12 13:07:56 59642 SOTBV UT_ SOTBV _Stress.inp Upper transition 08-29-12 13:07:56 50063

-_stress analysis for II Page 36

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary ColdStor ColdStor File Name Description Storage Storage Checksum Date Time SOTBV Upper transition UTSLBThermal.inp thermal analysis for 08-29-12 13:07:56 50940 SLB Upper transition UT_ SLB _Stress.inp stress analysis for 08-29-12 13:07:55 23420 SLB Upper transition UTHL-LOCAThermal.inp thermal analysis for 08-29-12 13:07:54 12424 HL-LOCA Upper transition UT_ HL-LOCA _Stress.inp stress analysis for 08-29-12 13:07:54 21991 HL-LOCA Lower transition LTPressureStress.inp stress analysis for 08-29-12 13:08:43 28780 pressure Lower transition LTCooldownThermal.inp thermal analysis for 08-29-12 13:08:42 01781 cooldown Lower transition LTCooldownStress.inp stress analysis for 08-29-12 13:08:41 18455 cooldown Lower transition LTSOTBVThermal.inp thermal analysis for 08-29-12 13:08:45 22786 SOTBV Lower transition LTSOTBVStress.inp stress analysis for 08-29-12 13:08:45 28683 SOTBV Lower transition LTSLBThermal.inp thermal analysis for 08-29-12 13:08:44 61563 SLB Lower transition LT_ SLB _Stress.inp stress analysis for 08-29-12 13:08:44 34617 SLB Lower transition LTHL-LOCAThermal.inp thermal analysis for 08-29-12 13:08:43 11332 HL-LOCA LT_ HL-LOCA _Stress.inp Lower transition 08-29-12 13:08:42 15025 stress analysis for Page 37

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary ANSYS Macros ColdStor ColdStor File Name Description Storage Storage Checksum Date Time GetathStrssDatamacstresses GetPathStressData.mac Lists upper transition 08-29-12 13:10:21 59228 Writes upper GetPathStress_Matrix.mac transition stress 08-29-12 13:10:22 51886 matrix Writes upper GetPathTempMatrix.mac transition 08-29-12 13:10:22 44880 temperature matrix Driver to list upper GetPressureStresses.mac transition pressure 08-29-12 13:10:23 18951 stresses Driver to write upper GetStress_M atrix. mac transition stress. 08-29-12 13:10:23 19746 matrix Driver to write upper GetTemperatureMatrix.mac transition 08-29-12 13:10:23 40572 temperature matrix GetLTPath_StressData.mac Lists lower transition 08-29-12 13:09:35 50463 stresses Writes lower GetLTPathStressMatrix.mac transition stress 08-29-12 13:09:35 60990 matrix Writes lower GetLTPathTemp_Matrix.mac transition 08-29-12 13:09:35 34445 temperature matrix Driver to list lower GetLTPressureStresses.mac transition pressure 08-29-12 13:09:36 41954 stresses Driver to write lower GetLTStressMatrix.mac transition stress. 08-29-12 13:09:36 28939 matrix Page 38

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary ColdStor ColdStor File Name Description Storage Storage Checksum Date Time Driver to write lower GetLT TemperatureMatrix.mac transition 08-29-12 13:09:37 64412 temperature matrix ANSYS Result Files ColdStor ColdStor File Name Description Storage Storage Checksum Date Time UTPathPressureStresses.txt Upper pressuretransition stresses 08-29-12 13:11:16 21571 Upper transition UTCooldown_ThermalCladTran.

mari cooldown emeatrs in n08-29-12 13:12:51 27492 matrix temperatures cladding Upper transition UTCooldownThermalBaseTran. cooldown 08-29-12 13:12:50 07522 matrix temperatures in base metal UTCooldownStressCladTran.ma Upper transition trix cooldown stresses 08-29-12 13:12:50 01178 in cladding UT Cooldown Stress BaseTran.m Upper transition atrix cooldown stresses 08-29-12 13:12:50 17455 in base metal Upper transition UTSOTBVThermalCladT ran.mat SOTBV 08-29-12 13:40:59 04693 rix temperatures in cladding Upper transition UT_SOTBVThermalBaseTran.ma SOTBV 08-29-12 13:40:59 32622 trix temperatures in base metal UTSOTBVStressCladTran.matri Upper transition SOTBV stresses in 08-29-12 13:40:58 23887 x cladding UT SOTBV Stress BaseTran.matri Upper transition U T t -SOTBV stresses in 08-29-12 13:40:58 63601 x base metal Page 39

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary ColdStor ColdStor File Name Description Storage Storage Checksum Date Time Upper transition S LB UTSLBThermalCladTran.matrix temperatures in 08-29-12 13:12:54 06451 cladding Upper transition S LB UTSLBThermalBaseTran.matrix temperatures in 08-29-12 13:12:54 07567 base metal UTSLBStressCladTran.matrix Upper transition SLB 08-29-12 13:12:53 64012 stresses in cladding Upper transition S LB UT_SLBStressBaseTran.matrix stresses in base 08-29-12 13:12:53 13912 metal UTHL- Upper transition HL-LOCAThermalCladTran.matrix LOCA temperatures 08-29-12 13:12:52 01145 in cladding UT_ HL- Upper transition HL-LOCAThermalBaseTran.matrix LOCA temperatures 08-29-12 13:12:52 49695 in base metal UT_ HL- Upper transition HL-LOCA stresses in 08-29-12 13:12:52 14078 LOCAStressCladT ran. matrix cladding UT_ HL- Upper transition HL-LOCA stresses in 08-29-12 13:12:51 22312 LOCAStressBaseT ran.matrix base metal LTPath_PressureStresses.txt Lower transition 08-29-12 13:14:05 34362 pressure stresses 082-2 1:45 336 Lower transition LTCooldow n_ThermalCladTran.m cooldown 08-29-12 13:14:53 01934 atrix temperatures in cladding Lower transition LTCooldown_ThermalBaseTran.

mari cooldown tmpraurs n08-29-12 13:14:53 25662 matrix temperatures in base metal LTCooldownStressCladT ran.mat Lower transition res r cooldown stresses 08-29-12 13:14:52 22331 rix in cladding LTCooldownStressBaseTran. ma Lower transition trix cooldown stresses 08-29-12 13:14:52 58275 in base metal Page 40

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AR EVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary ColdStor ColdStor File Name Description Storage Storage Checksum Date Time Lower transition LTSOTBVThermal_CladTran.mat SOTBV 08-29-12 13:15:59 03658 rix temperatures in cladding Lower transition LTSOTBVThermalBaseT ran. mat SOTBV 08-29-12 13:14:58 51308 rix temperatures in base metal Lower transition LTSOTBVStressCladTran.matrix SOTBV stresses in 08-29-12 13:14:58 44123 cladding LTSOTBVStressBaseTran.matri Lower transition L SOTBV stresses in 08-29-12 13:14:57 50774 x base metal Lower transition S LB LT_SLBThermal_CladTran.matrix temperatures in 08-29-12 13:14:57 64296 cladding Lower transition S LB LTSLBThermalBaseTran.matrix temperatures in 08-29-12 13:14:56 00642 base metal Lower transition S LB LT_SLBStress_CladTran.matrix strans.in .LB 08-29-12 13:14:56 43514 stresses incladding Lower transition S LB LT_SLBStress_BaseTran.matrix stresses in base 08-29-12 13:14:55 43135 metal LTHL- Lower transition HL-LOCA temperatures 08-29-12 13:14:55 25488 LOCA_Thermal_CladTran.matrix in cladding LT_ HL- Lower transition HL-LOCA temperatures 08-29-12 13:14:55 07000 LOCA_Thermal_BaseTran.matrix in base metal LT HL- Lower transition HL-LOCA stresses in 08-29-12 13:14:54 03885 LOCAStressCladT ran.matrix cladding LT HL- Lower transition HL-

- LOCA stresses in 08-29-12 13:14:54 05282 LOCA_Stress_BaseTran.matrix base metal Excel Spreadsheets Page 41

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary ColdStor ColdStor File Name Description Storage Storage Checksum Date Time Calculates upper UTTransitionSIF.xlsx transition stress 08-29-12 13:16:00 14801 intensity factors Calculates lower LTTransitionSIF.xlsx transition stress 08-29-12 13:15:59 58091 intensity factors UTTransitionEMA.xlsx Performs upper 08-29-12 13:15:59 33034 transition EMA LTTransitionEMA.xlsx Performs lower 08-29-12 13:15:58 30137 transition EMA ANSYS Test Cases ColdStor ColdStor File Name Description Storage Storage Checksum Date Time Cooling of a Spherical Body vml 12.inp Input file 08-29-12 13:16:22 56190 vml 12.vrt Output file 08-29-12 13:16:23 18908 Steady State Thermal Stresses in a Long Cylinder vm32mod.inp Input file 08-29-12 13:16:23 30984 vm32mod.vrt Output file 08-29-12 13:16:23 39656 Page 42

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary 8.0 EVALUATION FOR LEVELS A AND B SERVICE LOADINGS Initial flaw depths equal to 1/4 of the vessel wall thickness are analyzed for Levels A and B Service Loadings following the procedure outlined in Section 3.1 and evaluated for acceptance based on values for the J-integral resistance of the material from Section 5.4. The results of the evaluation for Levels A and B Service Loadings are presented in Table 8-1 and Table 8-2 for the upper and lower thickness transition welds, respectively. The ratio of material J-resistance (Jo.1) to applied J-integral (J1 ) is 3.58 for the upper transition weld and 3.67 for the lower transition weld. The minimum J(0.1)/J1 ratio, at 3.58, is greater than the minimum acceptable value of 1.0 required by the Code.

Flaw evaluations are continued for both transition welds by calculating applied J-integrals for various amounts of flaw extension with safety factors on pressure of 1.15 and 1.25. These results are presented in Table 8-3 for the upper transition weld and in Table 8-4 for the lower transition weld. Mean and lower bound J-R curve data are developed in Table 8-5 and Table 8-6 for the two weld locations.

The J-R curves data and applied J-integrals are plotted in Figure 8-1 for the upper transition weld and in Figure 8-2 for the lower transition weld. An evaluation line at a flaw extension 0.10 inch is used in these figures to confirm the results of Table 8-1 and Table 8-2 by showing that the applied J-integral for a safety factor of 1.15 is less than the lower bound J-integral resistance of the material. Figure 8-1 and Figure 8-2 also serve to demonstrate that the Code requirement for ductile and stable crack growth is satisfied since the slope of the applied J-integral curve for a safety factor of 1.25 is considerably less than the slope of the lower bound J-R curve at the point where the two curves intersect.

Page 43

For Ink '~n~C~ ýy Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table 8-1: Flaw Evaluation for Levels A & B Service Loadings - Upper Weld Dimensional data- Material data:

Ri =[ ]in.

t =E I in.

E = 25363 ksi ao= 2.1406 in. v= 0.3 Aa = 0.1 in. E'= 27871 ksi a=ao+Aa= 2.2406 in.

alt= 0.2617 (0.2_<a/t<0.5)

Loading data:-"

Pd = 2.500 ksi Pa = 2.750 ksi SF = 1.15 SIF solution: Chapuli ot, Lacire, and Le Delliou solution for circumferential flaws J(0. 1) J(0.1)/

Location Weld Extent Orient. Kip Kit Sy ae Kip' Kit' J1 at t14 Ji (ksi-Jin) (ksiJin) (ksi) (in.) (ksi< in) (ksiqin) (lb/in) (lb/in)

NBF/USF: WF-232 9% C 39.299 33.698 82.3 -2.2823 39.698 33.699 193 715 3.70 NBF/USF WF-233 91% C 39.299 33.698 82.3 2.2823 39.698 33.699 193 692 3.58 Note: Shaded row is not applicable since flaw depth is not within weld.

Page 44

Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table 8-2: Flaw Evaluation for Levels A & B Service Loadings - Lower Weld Dimensional data: Material data:

T=E[--F t L in.

E = 25363 ksi ao = 1.3785 in. v= 0,3 Aa = 0.1 in. E' = 27871 ksi a=ao+ Aa= 1.4785 in.

a/t= 0.2681 (0.2<a/t<0.5)

Loading data:

Pd = 2.500 ksi Pa = 2.750 ksi SF= 1.15 SIF solution: Chapuliot, Lacire, and Le Delliou solution for circumferential flaws J(0.1) J(0.1)/

Location Weld Extent Orient. KIp Kit Sy ae Kip' Kit' Ji at t/4 Ji (ksi'!in) (ksi-4jin) (ksi) (in.) (ksiIin) (ksiq1in) (lb/in) (lb/in)

LSF/DF WFý232 12% C 58.964 14.763 82.3 1.5211 59.714 14.736 199 749 3.77 LSF/DF WF-233 88% C 58.964 14.763 82.3 1.5211 59.714 14.736 199 730 3.67 Note: Shaded row is not applicable since flaw depth is not within weld.

Page 45

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table 8-3: J-Integral vs. Flaw Extension for Levels A & B Service Loadings - Upper Weld Ri = 85.6875 in. Pd = 2.500 ksi Location: NBF/USF t = 8.5625 in. Pa = 2.750 ksi Weld ID: WF-233 ao= 2.1406 in.

Sy = 82.3 ksi Flaw orientation: Circumferential E'= 27871 ksi SF = 1.15 SF = 1.25 Aa a a/t Kip Kit ae Kip' Kit' JA Kip Kit ae Kip' Kit' JA (in.) (in.) (ksi-in) (ksibin) (in.) (ksi.in) (ksikin) (lb/in) (ksi*/in) (ksi*/in) (in.) (ksi~in) (ksi'4in) (lb/in) 0.0000 2.1406 0.2500 38.336 33.668 2.1812 38.728 33.685 188.1 41.669 33.668 2.1850 42.136 33.687 206.3 0.0250 2.1656 0.2529 38.578 33.679 2.2065 38.972 33.693 189.4 41.932 33.679 2.2104 42.401 33.694 207.8 0.0500 2.1906 0.2558 38.819 33.688 2.2318 39.215 33.697 190.7 42.195 33.688 2.2357 42.665 33.698 209.2 0.0750 2.2156 0.2588 39.060 33.695 2.2571 39.457 33.699 192.0 42.456 33.695 2.2610 42.929 33.699 210.7 0.1000 2.2406 0.2617 39.299 33.698 2.2823 39.698 33.699 193.3 42.717 33.698 2.2863 43.191 33.699 212.1 0.1250 2.2656 0.2646 39.539 33.699 2.3076 39.939 33.696 194.5 42.977 33.699 2,3116 43.453 33.695 213.5 0.1500 2.2906 0.2675 39.777 33.698 2.3329 40.179 33.690 195.8 43.236 33.698 2.3370 43.715 33.689 215.0 0.1750 2.3156 0.2704 40.015 33.694 2.3581 40.418 33.682 197.0 43.495 33.694 2.3623 43.975 33.681 216.4 0.2000 2.3406 0.2734 40.252 33.688 2.3834 40.657 33.672 198.2 43.752 33.688 2.3876 44.235 33.670 217.8 0.2250 2.3656 0.2763 40.489 33.680 2.4087 40.895 33.659 199.4 44.010 33.680 2.4129 44.494 33.657 219.1 0.2500 2.3906 0.2792 40.725 33.669 2.4339 41.133 33.644 200.6 44.266 33.669 2.4382 44.753 33.642 220.5 0.2750 2.4156 0.2821 40.960 33.655 2.4592 41.370 33.627 201.8 44.522 33.655 2.4635 45.010 33.624 221.9 0.3000 2.4406 0.2850 41.195 33.640 2.4845 41.606 33.607 203.0 44.778 33.640 2.4888 45.268 33.604 223.2 0.3250 2.4656 0.2880 41.430 33.622 2.5097 41.842 33.585 204.1 45.033 33.622 2.5140 45.525 33.581 224.5 0.3500 2.4906 0.2909 41.664 33.602 2.5350 42.078 33.561 205.3 45.287 33.602 2.5393 45.781 33.557 225.8 0.3750 2.5156 0.2938 41.897 33.580 2.5602 42.313 33.535 206.4 45.541 33.580 2.5646 46.037 33.530 227.1 0.4000 2.5406 0.2967 42.131 33.556 2.5855 42.548 33.507 207.5 45.794 33.556 2.5899 46.292 33.502 228.4 0.4250 2.5656 0.2996 42.363 33.529 2.6107 42.782 33.476 208.6 46.047 33.529 2.6152 46.547 33.471 229.7 0.4500 2.5906 0.3026 42.595 33.501 2.6359 43.016 33.444 209.8 46.299 33.501 2.6405 46.802 33.438 231.0 0.4750 2.6156 0.3055 42.827 33.470 2.6612 43.249 33.409 210.8 46.551 33.470 2.6657 47.056 33.403 232.3 0.5000 2.6406 0.3084 43.059 33.437 2.6864 43.482 33.372 211.9 46.803 33.437 2.6910 47.309 33.366 233.5 Page 46

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table 8-4: J-Integral vs. Flaw Extension for Levels A & B Service Loadings - Lower Weld Ri = in. Pd = 2.500 ksi Location: LSF/DF t= in, Pa = 2.750 ksi Weld ID: WF-233 ao = .37J in.

Sy = 82.3 ksi Flaw orientation: Circumferential E'= 27871 ksi SF = 1.15 SF = 1.25 Aa a a/t Kip Kit ae Kip' Kit' J Kip Kit ae Klp' Kit' JA (in.) (in.) (ksi-in) (ksilin) (in.) (ksi'lin) (ksi'/in) (lb/in) (ksi/in) (ksi'/in) (in.) (ksi.4in) (ksi.4in) (Ib/in) 0.0000 1.3785 0.2500 57.166 14.802 1.4191 57.902 14.791 189.6 62.137 14.802 1.4249 63.050 14.789 217.4 0.0250 1.4035 0.2545 57.621 14.796 1.4446 58.360 14.781 191.9 62.632 14.796 1.4504 63.549 14.778 220.1 0.0500 1.4285 0.2591 58.072 14.788 1.4701 58.815 14.768 194.3 63.122 14.788 1.4760 64.044 14.765 222.8 0.0750 1.4535 0.2636 58.520 14.777 1.4956 59.266 14.753 196.6 63.609 14.777 1.5016 64.535 14.749 225.5 0.1000 1.4785 0.2681 58.964 14.763 1.5211 59.714 14.736 198.9 64.092 14.763 1.5272 65.023 14.731 228.2 0.1250 1.5035 0.2727 59.406 14.748 1.5466 60.160 14.716 201.2 64.572 14.748 1.5528 65.508 14.711 230.9 0.1500 1.5285 0.2772 59.845 14.730 1.5721 60.602 14.695 203.4 65.049 14.730 1.5783 65.991 14.689 233.5 0.1750 1.5535 0.2817 60.281 14.710 1.5975 61.043 14.671 205.7 65.523 14.710 1.6039 66.470 14.665 236.2 0.2000 1.5785 0.2863 60.714 14.689 1.6230 61.480 14.645 207.9 65.994 14.689 1.6295 66.946 14.639 238.8 0.2250 1.6035 0.2908 61.146 14.665 1.6485 61.916 14.618 210.2 66.463 14.665 1.6550 67.420 14.611 241.4 0.2500 1.6285 0.2953 61.574 14.640 1.6740 62.349 14.589 212.4 66.929 14.640 1.6806 67.892 14.581 244.0 0.2750 1.6535 0.2999 62.001 14.612 1.6995 62.780 14.558 214.6 67.392 14.612 1.7062 68.362 14.549 246.6 0.3000 1.6785 0.3044 62.426 14.583 1.7249 63.209 14.525 216.8 67.854 14.583 1.7317 68.829 14.516 249.2 0.3250 1.7035 0.3089 62.848 14.552 1.7504 63.636 14.490 219.0 68.313 14.552 1.7573 69.295 14.481 251.8 0.3500 1.7285 0.3135 63.269 14.520 1.7759 64.062 14.454 221.2 68.771 14.520 1.7828 69.758 14.444 254.4 0.3750 1.7535 0.3180 63.688 14.486 1.8014 64.486 14.416 223.4 69.227 14.486 1.8084 70.220 14.406 257.0 0.4000 1.7785 0.3225 64.106 14.450 1.8268 64.909 14.377 225.5 69.680 14.450 1.8339 70.681 14.366 259.5 0.4250 1.8035 0.3271 64.522 14.413 1.8523 65.330 14.337 227.7 70.133 14.413 1.8595 71.139 14.325 262.1 0.4500 1.8285 0.3316 64.937 14.375 1.8778 65.750 14.295 229.9 70.583 14.375 1.8850 71.597 14.282 264.6 0.4750 1.8535 0.3361 65.350 14.335 1.9032 66.168 14.251 232.0 71.033 14.335 1.9106 72.053 14.238 267.2 0.5000 1.8785 0.3407 65.762 14.293 1.9287 66.586 14.206 234.2 71.481 14.293 1.9361 72.508 14.193 269.7 Page 47

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AR EVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table 8-5: J-R Data for Evaluation of Levels A & B Service Loadings - Upper Weld Location: NBF/USF Weld ID: WF-233 tZ in.

ao= 2.140M in. attV4 Fsurf = 2.27 1018 n/cm 2 @ cladding/base metal interface Cu = 0.21 Bn = 0.80 in As a Fl InC1 C1 C2 C3 J-R 1b/in)

(in.) (in.) (1018 n/cm 2 ) Mean Low 0.001 2.1416 1.3577 0.55258 1.73773 0.12520 -0.09788 83 58 0.002 2.1426 1.3574 0.55259 1.73775 0.12521 -0.09788 162 113 0.004 2.1446 1.3567 0.55261 1.73778 0.12521 -0.09788 271 189 0.007 2.1476 1.3557 0.55264 1.73783 0.12521 -0.09788 377 263 0.010 2.1506 1.3548 0.55267 1.73788 0.12522 -0.09788 450 315 0.015 2.1556 1.3531 0.55272 1.73797 0.12522 -0.09789 539 377 0.020 2.1606 1.3515 0.55277 1.73805 0.12523 -0.09789 604 422 0.030 2.1706 1.3483 0.55286 1.73822 0.12524 -0.09789 699 488 0.040 2.1806 1.3450 0.55296 1.73839 0.12525 -0.09789 767 536 0.050 2.1906 1.3418 0.55306 1.73856 0.12526 -0.09789 821 574 0.070 2.2106 1.3354 0.55325 1.73890 0.12528 -0.09789 902 631 0.100 2.2406 1.3258 0.55355 1.73941 0.12532 -0.09789 990 692 0.120 2.2606 1.3195 0.55374 1.73975 0.12534 -0.09789 1035 724 0.140 2.2806 1.3132 0.55394 1.74009 0.12536 -0.09790 1073 750 0.160 2.3006 1.3069 0.55413 1.74043 0.12539 -0.09790 1107 774 0.200 2.3406 1.2944 0.55452 1.74111 0.12543 -0.09790 1163 813 0.250 2.3906 1.2789 0.55501 1.74195 0.12549 -0.09791 1220 853 0.300 2.4406 1.2637 0.55549 1.74280 0.12554 -0.09791 1268 885 0.350 2.4906 1.2486 0.55598 1.74364 0.12560 -0.09791 1306 913 0.400 2.5406 1.2337 0.55646 1.74449 0.12566 -0.09792 1341 938 0.450 2.5906 1.2190 0.55694 1.74533 0.12571 -0.09792 1372 959 0.500 2.6406 1.2045 0.55743 1.74617 0.12577 -0.09793 1400 979 Page 48

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table 8-6: J-R Data for Evaluation of Levels A & B Service Loadings - Lower Weld Location: LSF/DF Weld ID: WF-233 t Fin.

ao= 1.3785 in. at t/4 Fsurf = 0.228 1018 n/cm 2 @ cladding/base metal interface Cu = 0.21 Bn= 0.80 in Aa a Fl InC1 C1 C2 C3 J-R (lb/in)

(in.) (in.) (1018 n/cm 2 ) Mean Low 0.001 1.3795 0.1637 0.62844 1.87469 0.13404 -0.09858 83 58 0.002 1.3805 0.1637 0.62845 1.87471 0.13404 -0.09858 164 115 0.004 1.3825 0.1636 0.62847 1.87473 0.13404 -0.09858 276 193 0.007 1.3855 0.1635 0.62849 1.87478 0.13404 -0.09858 386 270 0.010 1.3885 0.1634 0.62851 1.87482 0.13404 -0.09858 464 324 0.015 1.3935 0.1632 0.62855 1.87489 0.13405 -0.09858 558 390 0.020 1.3985 0.1630 0.62859 1.87496 0.13405 -0.09858 627 438 0.030 1.4085 0.1626 0.62866 1.87510 0.13406 -0.09858 728 509 0.040 1.4185 0.1622 0.62874 1.87524 0.13407 -0.09858 802 560 0.050 1.4285 0.1618 0.62881 1.87538 0.13408 -0.09858 860 601 0.070 1.4485 0.1610 0.62896 1.87567 0.13410 -0.09859 948 663 0.100 1.4785 0.1599 0.62919 1.87609 0.13412 -0.09859 1044 730 0.120 1.4985 0.1591 0.62934 1.87637 0.13414 -0.09859 1094 765 0.140 1.5185 0.1584 0.62949 1.87665 0.13416 -0.09859 1136 794 0.160 1.5385 0.1576 0.62964 1.87693 0.13417 -0.09859 1173 820 0.200 1.5785 0.1561 0.62994 1.87750 0.13421 -0.09859 1235 863 0.250 1.6285 0.1542 0.63031 1.87820 0.13425 -0.09860 1298 907 0.300 1.6785 0.1524 0.63069 1.87890 0.13430 -0.09860 1349 943 0.350 1.7285 0.1506 0.63106 1.87960 0.13434 -0.09860 1394 974 0.400 1.7785 0.1488 0.63143 1.88030 0.13438 -0.09861 1433 1002 0.450 1.8285 0.1470 0.63180 1.88100 0.13443 -0.09861 1467 1026 0.500 1.8785 0.1453 0.63217 1.88170 0.13447 -0.09862 1498 1047 Page 49

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary J-Integral (lb/in) 14oo, ~*1 I Y 1200 1000 800 600 000,_ J-R Mean

-J-R Lower Bound Japp w/ SF=1.25

-Jappw/ SF=1.15 400 inEvaluation Line for SF1 .15 200 n L 0.00 0.05 0.10 0.15 0.20 0.25 Flaw Extension, Aa (in.)

Figure 8-1: J-Integral vs. Flaw Extension for Levels A & B Service Loadings - Upper Weld Page 50

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary J-Integral (lb/in) 14MU 1200 1000 800 600 _ _ J-R Mean J-R Lower Bound Jappw/ SF=1 -25 SJappw/ SF=1.15 400 ine for SF=1 .15

=

!Eaubo 200 n

0.00 0.05 0.10 0.15 0.20 0.25 Flaw Extension, Aa (in.)

Figure 8-2: J-Integral vs. Flaw Extension for Levels A & B Service Loadings - Lower Weld Page 51

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary 9.0 EVALUATION FOR LEVELS C AND D SERVICE LOADINGS Flaw evaluations for Levels C and D Service Loadings follow the procedure outlined in Section 3.2. A base metal flaw depth of 0.8125 inch is used for the upper transition weld since 1/10 of the base metal thickness ( [ ] ) plus the cladding thickness (0.1875") equals 1.0438 inch, which exceeds the Section XI, Appendix K maximum flaw depth of 1.0 inch. The ratio of the postulated flaw depth to the thickness of the base metal is then 0.0949. At the lower transition weld, the base metal flaw depth is 0.5514 inch since 1/j0 of the thickness of the base metal ([ J ) is less than 0.8125 inch (1.0" minus 0.1875" cladding).

Applied stress intensity factors, K1, are obtained for each of the three Levels C and D Service Loadings described in Section 6.2, the stuck open turbine bypass valve transient, the steam line break transient, and the loss of coolant transient. Stress intensity factors are calculated for deadweight, pressure, and thermal loads and include the effects of cladding and residual stress. Base metal flaw depths of 0.2141 inch (a/t = .025), 0.4281 inch (a/t = .050), 0.6422 inch (a/t = .075), and the maximum postulated depth of 0.8125 inch plus a 0.1 inch flaw extension (total a/t = .1066) are analyzed for the upper transition weld to determine the most limiting flaw depth. Corresponding flaw depths of 0.1379 inch (a/t = .025),

0.2757 inch (a/t = .050), 0.4136 inch (a/t = .075), and 0.6514 inch (a/t = .1181) are analyzed for the lower transition weld.

To determine the controlling transient and the critical time within that transient for the Level C and D flaw evaluations, values of material fracture toughness are calculated for both the transition and upper-shelf temperature regions. Transition region toughness is obtained from the ASME Section XI equation for crack initiation [2],

Kic = 33.2 + 20.734 exp[ 0.02 ( T - RT NDT) I where K1, = transition region toughn ess, ksi4in T = crack tip temperature, °F Upper-shelf toughness is derived from the J-integral resistance model of Section 5.1 as follows:

Kjc= Jo. 1 E K1000(1-v )

where Kjc = upper-shelf region toughness, ksi/in Jo.1 = J-integral resistance at Aa = 0.1 in.

The following location specific parameters are used to calculate values of toughness at the maximum postulated depths:

Flaw depth = 0.9125 inch for the upper weld and 0.6514 inch for the lower weld RTNDT = 112.5 OF for the upper weld and 69.2 OF for the lower weld Page 52

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Fluence = 1.82 x 1018 n/cm 2 for the upper weld and 0.195 x 1018 n/cm 2 for the lower weld Figure 9-1 shows the variation of applied stress intensity factor, KI, transition toughness, K1c, and upper-shelf toughness, Kic with temperature for all three transients at a flaw depth of a/t = 0.1066 at the upper transition weld. Similar results are presented in Figure 9-2 for a flaw depth of a/t = 0.1181 at the lower transition weld. It is readily seen from these figures that the controlling transient is the hot leg LOCA for both weld locations. The small rectangles on the HL-LOCA K, curves in Figure 9-1 and Figure 9-2 indicate output time points from the finite element solutions. In the upper-shelf toughness range, the K, curve is closest to the lower bound Kjc curve at 6.036 and 3.114 minutes into the transient for the upper and lower weld locations, respectively. These times are therefore selected as the critical times for evaluating for Levels C and D Service Loadings.

The most limiting flaw depth at the upper weld location is determined by plotting KI and Kj, along with K1c, as a function of crack tip temperature for four flaw depths in Figure 9-3. Similar plots are presented in Figure 9-4 for the lower weld location. The data in these figures were derived for the controlling time during the hot leg LOCA transient at each flaw depth. These plots clearly show that the available margin decreases with increasing flaw depth up to the maximum required flaw depth for each transition weld, thereby confirming that the maximum required flaw depth is the most limiting flaw depth at each weld location.

In order to track the applied J-integral with flaw extension, Table 9-1 and Table 9-2 calculate values of the applied J-integral at various flaw depths for the critical time points during the controlling loss of coolant transient, at 6.036 and 3.114 minutes for the upper and lower transition welds, respectively.

Stress intensity factors are converted to J-integrals by the plain strain relationship, 2 ).

Japplied (a) = 1000 K2E(a) (1-v The applied J-integrals from Table 9-1, along with the mean and lower bound J-R data developed in Table 9-3 for the upper transition weld are plotted in Figure 9-5 as a function of flaw extension. Similar results are plotted in Figure 9-6 using J-integrals from Table 9-2 and J-R developed in Table 9-4 for the lower transition weld. Evaluation lines are used at a flaw extension 0.10 in. to show that the applied J-integral is less than the lower bound J-integral of the material, as required by Appendix K [2]. The ratio of material J-resistance (J0.1) to applied J-integral (J1 ), calculated in Table 9-1 and Table 9-2, is 3.15 for the upper transition weld and 4.73 for the lower transition weld, both of which are greater than the minimum acceptable value of 1.0 required by the Code. Figure 9-5 and Figure 9-6 also serve to demonstrate that the Code requirement for ductile and stable crack growth is satisfied since the slope of the applied J-integral curve for a safety factor of 1.25 is considerably less than the slope of the lower bound J-R curve at the point w here the two curves intersect.

ASME Code Section Xl, Article K-5300(b) [2], requires that for Level D Service Loadings the total flaw depth after stable flaw extension be no greater than 75% of the vessel wall thickness. Figure 9-7 and Figure 9-8, which plot the material and applied J-integrals as a function of the ratio of flaw depth to thickness (a/t), demonstrate that this requirement is satisfied since the applied J-integrals peak at about 20% of the wall thickness for both the upper and lower transition welds.

Page 53

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Article K-5300(b) [2] also requires that the remaining ligament is not subject to tensile instability. This requirement is satisfied by showing that the internal pressure is less than the internal pressure at the tensile instability of the remaining ligament, which for a circumferential flaw is defined as, Pinstability = 1.07 a 0R

/(2Rt) (Ac /A)l where

a. = flow stress = (ay+au)/2 A = an area parameter = t(t+t)

Ac = area of the flaw = irat/4 and Ri = inner radius of the vessel Rm = mean radius of the vessel t = wall thickness of the vessel a = flaw depth f = flaw length = 6a An additional check is performed for circumferential flaws to ensure that internal pressure does not exceed that pressure at tensile instability caused by the applied hoop stress acting over the nominal wall thickness of the vessel. This validity limit on pressure is satisfied by t

instability < 1.07 0 *-.i Table 9-5 and Table 9-6 present the necessary calculations to demonstrate the remaining ligament is not subject to tensile instability using a flaw depth equal to 0.8125 inch plus a 0.10 inch flaw extension for the upper transition weld and 0.5514 inch plus a 0.10 inch flaw extension for the lower transition weld. For the upper transition weld, the internal pressure at tensile instability is calculated to be 15,625 psi while the validity check on hoop stress limits the internal pressure to 7745 psi. For the lower transition weld, the internal pressure at tensile instability is calculated to be 9849 psi while the validity check on hoop stress limits the internal pressure to 4987 psi, which is still much greater than the maximum pressure of 2185 psi during the hot leg LOCA transient.

Page 54

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table 9-1: J-Integral vs. Flaw Extension for Hot Leg Loss of Coolant Accident - Upper Weld Time = 6.036 min.

Crack tip at ao = 0.8125 in. t= / ]in. v=

DPTC* Residual Total Aa a a/t Temp. E Sy KI KI KI w/ae Japp (in.) (in.) (F) (ksi) (ksi) (ksi-/in) (ksi'/in) (ksi'in) (lb/in) 0.0000 0.8125 0.0949 393.3 26234 61.9 86.22 -5.97 84.55 248.0 0.0250 0.8375 0.0978 395.0 26225 61.8 86.74 -6.05 84.93 250.3 0.0500 0.8625 0.1007 396.8 26216 61.8 87.23 -6.12 85.29 252.5 0.0750 0.8875 0.1036 398.5 26207 61.8 87.69 -6.18 85.65 254.7 0.1000 0.9125 0.1066 400.2 26199 61.7 88.14 -6.24 85.99 256.8 0.1500 0.9625 0.1124 403.7 26182 61.7 88.98 -6.37 86.60 260.7 0.2500 1.0625 0.1241 410.4 26148 61.6 90.45 -6.61 87.63 267.2 0.4500 1.2625 0.1474 423.2 26084 61.4 92.69 -6.65 89.52 279.6 0.7500 1.5625 0.1825 441.3 25993 61.2 94.72 -7.56 90.12 284.3 1.1000 1.9125 0.2234 460.6 25897 60.9 94.77 -7.92 89.26 280.0 1.5000 2.3125 0.2701 480.4 25798 60.6 93.79 -8.26 87.46 269.8 2.0000 2.8125 0.3285 501.9 25688 60.3 91.75 -8.18 85.07 256.3 2.5000 3.3125 0.3869 520.1 25579 60.0 90.01 -8.63 82.57 242.5 3.0000 3.8125 0.4453 535.3 25488 59.8 89.45 -9.35 81.09 234.8

• DPTC KI = Deadweight KI + Pressure KI + Thermal KI + Cladding KI At Aa = 0.10 in., J1 = Japp = 257 lb/in.

J(0.1) = J-R at Aa of 0.1 in. = 810 lb/in.

J(0.1)/J1 = 3.15 Page 55

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table 9-2: J-Integral vs. Flaw Extension for Hot Leg Loss of Coolant Accident - Lower Weld Time = 3.114 min.

Crack tip at ao = 0.5514 in. t= / /in. v= 0.3 DPTC* Residual Total Aa a a/t Temp. E Sy KI KI KI Japp (in.) (in.) (F) (ksi) (ksi) (ksi4in) (ksi'/in) (ksi!in) (lb/in) 0.0000 0.5514 0.1000 410.4 26148 61.6 73.21 -6.09 70.86 174.7 0.0250 0.5764 0.1045 412.7 26136 61.6 73.60 -6.18 71.04 175.7 0.0500 0.6014 0.1091 415.1 26125 61.5 73.95 -6.28 71.20 176.6 0.0750 0.6264 0.1136 417.4 26113 61.5 74.27 -6.37 71.32 177.3 0.1000 0.6514 0.1181 419.7 26101 61.5 74.56 -6.47 71.41 177.8 0.1500 0.7014 0.1272 424.3 26079 61.4 75.05 -6.62 71.57 178.7 0.2000 0.7514 0.1363 428.7 26056 61.3 75.42 -6.62 71.79 180.0 0.3000 0.8514 0.1544 437.4 26013 61.2 75.89 -6.78 71.81 180.4 0.4000 0.9514 0.1725 445.7 25971 61.1 76.06 -7.37 71.06 176.9 0.5000 1.0514 0.1907 453.7 25932 61.0 75.80 -7.64 70.27 173.3 0.7500 1.3014 0.2360 472.2 25839 60.7 74.40 -8.05 67.94 162.6 1.0000 1.5514 0.2814 488.8 25756 60.5 72.46 -8.28 65.40 151.1 1.4000 1.9514 0.3539 511.5 25631 60.2 69.18 -8.14 61.89 136.0 1.8000 2.3514 0.4264 529.9 25521 59.9 67.22 -9.13 58.71 122.9

• DPTC KI = Deadweight KI + Pressure KI + Thermal KI + Cladding KI At Aa = 0.10 in., J1 = Japp = 178 lb/in.

J(0.1) = J-R at Aa of 0.1 in. = 841 lb/in.

J(0.1)/J1 = 4.73 Page 56 I

For Information Only Document No. 32-9195651-000 A

AREVA NON - PROPRIETARY Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table 9-3: J-R Curve Data for Evaluation of Levels C & D Service Loadings - Upper Weld Location: NBFIUSF Weld ID: WF-233 t in.

so in. (aoyt = 0.0949 Tim* = 362.160 min.

Fsurf = 2.27 1018 n/cm 2 Q cladding/base metal interface CU = 0.21 Bn = 0.80 in As a Fl InCi C1 C2 C3 J-R (Ib/in)

(in.) (in.) (1018 n/cm 2 ) Mean Low 0.001 0.8135 1.8674 0.77483 2.17021 0.15107 -. 09993 83 58 0.002 0.8145 1.8669 0.77484 2.17024 0.15108 -. 09993 167 117 0.004 0.8165 1.8660 0.77486 2.17028 0.15108 -0.09993 286 200 0.007 0.8195 1.8647 0.77489 2.17035 0.15108 -. 09993 406 284 0.010 0.8225 1.8634 0.77492 2.17041 0.15108 -0.09993 491 343 0.015 0.8275 1.8611 0.77497 2.17052 0.15109 -. 09993 596 416 0.020 0.8325 1.8589 0.77502 2.17063 0.15110 -0.09993 674 471 0.030 0.8425 1.8544 0.77512 2.17085 0.15111 -0.09993 789 552 0.040 0.8525 1.8500 0.77522 2.17107 0.15112 -0.09993 874 611 0.050 0.8625 1.8456 0.77532 2.17129 0.15113 -0.09993 941 658 0.070 0.8825 1.8367 0.77553 2.17174 0.15116 -0.09993 1045 730 0.100 0.9125 1.8235 0.77583 2.17240 0.15119 -0.09994 1158 810 0.120 0.9325 1.8148 0.77603 2.17284 0.15121 -0.09994 1217 851 0.140 0.9525 1.8061 0.77624 2.17328 0.15124 -0.09994 1268 886 0.160 0.9725 1.7975 0.77644 2.17372 0.15126 -0.09994 1312 917 0.200 1.0125 1.7803 0.77684 2.17460 0.15131 -0.09994 1387 970 0.250 1.0625 1.7591 0.77735 2.17570 0.15137 -0.09995 1464 1024 0.300 1.1125 1.7381 0.77785 2.17680 0.15143 -0.09995 1528 1068 0.350 1.1625 1.7173 0.77836 2.17789 0.15149 -0.09996 1583 1106 0.400 1.2125 1.6969 0.77886 2.17899 0.15154 -0.09998 1631 1140 0.450 1.2625 1.6766 0.77936 2.18008 0.15160 -0.09997 1674 1170 0.500 1.3125 1.6566 0.77987 2.18118 0.15166 -0.09997 1713 1198 Page 57

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AR EVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table 9-4: J-R Curve Data for Evaluation of Levels C & D Service Loadings - Lower Weld Location: LSF/DF Weld ID: WF-232 t= in.

ao in. (aoyt = 0.1000 Time- 186.840 min.

Fsurf = 0.228 1018 n/cm 2 claddingbse metal interface Cu = 0.21 Bn = 0.80 in Aa a Fl InC C1 C2 C3 J-R (Ib/in)

(in.) (in.) (1018 n/cm 2) Mean Low 0.001 0.5524 0.1997 0.82821 2.28922 0.15729 -0.10042 83 58 0.002 0.5534 0.1996 0.82822 2.28924 0.15729 -0.10042 168 117 0.004 0.5554 0.1995 0.82823 2.28927 0.15729 -0.10042 290 203 0.007 0.5584 0.1994 0.82826 2.28933 0.15729 -0.10042 413 289 0.010 0.5614 0.1993 0.82828 2.28938 0.15730 -0.10042 502 351 0.015 0.5664 0.1990 0.82832 2.28947 0.15730 -0.10042 610 427 0.020 0.5714 0.1988 0.82836 2.28958 0.15731 -0.10042 692 484 0.030 0.5814 0.1983 0.82843 2.28973 0.15731 -0.10042 812 568 0.040 0.5914 0.1978 0.82851 2.28991 0.15732 -0.10042 901 630 0.050 0.6014 0.1974 0.82859 2.29009 0.15733 -0.10042 972 680 0.070 0.6214 0.1964 0.82874 2.29044 0.15735 -0.10042 1082 757 0.100 0.6514 0.1950 0.82897 2.29097 0.15738 -0.10042 1202 841 0.120 0.6714 0.1941 0.82913 2.29132 0.15740 -0.10043 1265 885 0.140 0.6914 0.1931 0.82928 2.29167 0.15741 -0.10043 1319 922 0.160 0.7114 0.1922 0.82944 2.29202 0.15743 -0.10043 1367 955 0.200 0.7514 0.1904 0.82974 2.29273 0.15747 -0.10043 1447 1012 0.250 0.8014 0.1881 0.83013 2.29361 0.15751 -0.10043 1529 1069 0.300 0.8514 0.1859 0.83051 2.29449 0.15756 -0.10044 1597 1117 0.350 0.9014 0.1836 0.83089 2.29536 0.15760 -0.10044 1656 1158 0.400 0.9514 0.1815 0.83127 2.29624 0.15764 -0.10044 1708 1194 0.450 1.0014 0.1793 0.83165 2.29711 0.15769 -0.10045 1754 1226 0.500 1.0514 0.1772 0.83203 2.29799 0.15773 -0.10045 1796 1256 Page 58

For Information Only Document No. 32-9195851-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table 9-5: Tensile Instability Check for Level D Service Loadings - Upper Weld Per Article K-5300(b) [2]:

For circumferential laws, Pinstability = 1.07 a{[ 1 - (AcIA) ]l/[ IV(2Rmt) + (k/A) ]

Let: soa 0.8125 in.

Aa a 0.1000 in.

a-e,+Asa- 0.9125 in.

Rt ]in.

I= a 5.4750 in.

A=t(t+t)= 120.2 in2 Acn=eI4= 3.924 in2 Using a consentihely high temperature of 600 °F,

=o: 72.43 ksi Pinstability = 15.625 ksi Validity check:

Pinstability < 1.07 a, t/R-Pinstability < 7.745 ksi Page 59

For Information Only Document No. 32-9195851-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary Table 9-6: Tensile Instability Check for Level D Service Loadings - Lower Weld Per Article K-5300(b) [2]:

For circumfrential laws, Pinstability = 1.07 a{ [ 1 - (At/A) 11 [ R-2/(2Rt) + (A,/A)])

Let: ao = 0.5514 in.

Aa& 0.1000 in.

a&ao+Aa= 0.6514 in.

=/lin.

t.L

= __in.

I= 6a= L.08 in.

Aut(t+t)= 51.96 in2 A, =aW14 2.000 in2 Using a conserwtivWy high temperature of 600 *F, co= 72.43 ksi Pinstability = 9.849 ksi Validity check:

Pinstability < 1.07 cr0 t/R-Pinstability :5 4.987 ksi Page 60

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AR EVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary KI (ksiin) 3 0 0 r-275 I I

- KJc Mean I - KJc Lower Bound 250

"-"- KI for HL-LOCA 225 S- KI for SLB I- KI for SOTBV

.... Upper Shelf Lim it 200 175 150 125 -I I

/

/

/ I

• i Evaluation point at 6.036 min.

100 into limiting transient 75

• I 50 25

• I I

I 0 I Upper-Sheof Toughness Range

-25 175 200 225 250 275 300 325 350 375 400 425 450 475 500 525 550 575 600 Crack Tip Temperature (F)

Figure 9-1: KI vs. Crack Tip Temperature for Levels C & D Service Loadings - Upper Weld Page 61 I

For Information Only Document No. 32-9195851-000 A NON - PROPRIETARY AR EVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary KI (ksiin) 300 r 275

.... KIc

-KJc Mean 250 I - KJc Lower Bound i KIfor HL-LOCA VJ 225 IKI for SLB

KI for SOTBV i I .... Upper Shelf Limit 200 175 iI 150

• i 125 100

• i!

I Evaluation point at 3.114 min.

• I into limiting transient 75 50 25 0

Upper-Shelf Toughness Range I-

-25 150 175 200 225 250 275 300 325 350 375 400 425 450 475 500 525 550 575 600 Crack Tip Temperature (F)

Figure 9-2: KI vs. Crack Tip Temperature for Levels C & D Service Loadings - Lower Weld Page 62 I

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AR EVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Propretay KI (ksi4in) 300oo I

U-I KIc a/t= .1066 w/ RTrndt = 112.5 275 - K:Ica/t=.075w/lRTndt= 115.1 I --- KIcQa/t =.050w/RTndt= 1172 I .- KIc alt= .025 w IRTndt

= 119.4 250

- - - KJc Low Q aft =0.1066 & da =0.1 In.

- - - KJc Low a/t =.075 &da = 0.1 In.

225 - - - KJc Low @ alt =.050 &da z 0.1 In.

I

- - - KJc Low @aat =.025 &da = 0.1 In.

2O0 -* KI@ alt= .1066 & 6.036 min.

- KI Q aft = .075 & 5.454 min.

- KI @ aft - .050 &4.866 min.

175

ý ý ý - - ý -b . ft

- KI Q aft = .025 &4284 min.

I I

- - - J 150 125 I

100 75 50 25 0

-251 175 200 225 250 275 300 325 350 375 400 425 450 475 500 525 550 575 600 Crack Tip Temperature (F)

Figure 9-3: KI vs. Crack Tip Temperature for Various Flaw Depths - Upper Weld Page 63 I

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AR EVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietay KI (ksi'lin)

,amn

.,'Ju I S-UKIc@0 a t .1066 w/RTndt = 692

- Kic Q a/t = .075 w/ RTndt a 70.7 275

--- Kic aft= .050 w/ RTndt = 71.6

-U- Kic 0 ait = .025 w RTndt = 72.5 250

- - - KJc Low Q a/t a 0.1181 & da O0.1 In.

- - - KJc Low @ aft =.075 & da = 0.1 In.

225 - - - KJcLowQ aft =.050 &da = 0.1 In.

- - KJc Low @af = .025 &da a 0.1 In.

200 KI@ a/t =.1181 &3.114 min.

KI Q a/t z.075 &3.114 mIn.

175 - KI @ a/t = .050 &2.526 min.

- - - - - = - - - - n - - = - KI Q aft = .025 &2.526 min.

150 I

125 100 75 50 25 0

-25 150 175 200 225 250 275 300 325 350 375 400 425 450 475 500 525 550 575 600 Crack Tip Temperature (F)

Figure 9-4: KI vs. Crack Tip Temperature for Various Flaw Depths - Lower Weld Page 64

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary J-Integral (lb/in) 1800 1600 1400 1200 1000 800-600 400-200-0-

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 Flaw Extension, Aa (in.)

Figure 9-5: J4nbegral vs. Flaw Extension for Levels C & D Service Loadings - Upper Weld Page 65

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary J-Integral (lb/in) 1800 -

1600 1400 1200 1000 800 600 400 200 0

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 Flaw Extension, Aa (in.)

Figure 9-6: J-Integral vs. Flaw Extension for Levels C & D Service Loadings - Lower Weld Page 66

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietal*y J-Integral (lb/in) 3 000.

2500 200=

1500 1000 500 0

0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 Flaw Depth to Thickness Ratio, alt Figure 9-7: J-Integral vs. a/t for Levels C & D Service Loadings - Upper Weld Page 67

For Information Only Document No. 32-9195651-000 A

AREVA NON - PROPRIETARY Equrvalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary J-Integral (lb/in) 300=

2500 2000 1500 1000 500 0

0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 Flaw Depth to Thickness Ratio, a/t Figure 9-8: J-Integral vs. alt for Levels C & D Service Loadings - Lower Weld Page 68

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AR EVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary 10.0

SUMMARY

OF RESULTS Fracture mechanics analysis has been used to perform an equivalent margins assessment of the circumferential transition welds at Davis Besse Unit 1 in order to evaluate the potential for low upper-shelf energy levels at 52 EFPY. The Davis Besse reactor vessel contains an upper WF-232/233 weld located where the ] upper shell forging transitions to the [ ] nozzle belt forging and a lower WF-232/233 weld where the [ ] Dutchman forging attaches to the [ ] lower shell forging.

It has been shown that ASME Code,Section XI, Appendix K [2] acceptance criteria have been satisfied for Levels A and B Service Loadings based on the following:

(1) Figure 8-1 and Figure 8-2 show that with factors of safety of 1.15 on pressure and 1.0 on thermal loading, the applied J-integral (J1) is less than the J-integral of the material at a ductile flaw extension of 0.10 inch (Jo01) for both the upper and lower transition welds.

From Table 8-1, the ratio of the lower bound J-R curve to the applied J-integral, Joi./J 1, is 692/193, or 3.58 at the upper transition weld. Table 8-2 shows that this ratio is 730/199, or 3.67, at the lower transition weld. These ratios are well above the Code required value of 1.0.

(2) Figure 8-1 and Figure 8-2 show that with factors of safety of 1.25 on pressure and 1.0 on thermal loading, flaw extensions are ductile and stable at both weld locations since the slope of the applied J-integral curve is less than the slope of the lower bound J-R curve at the point where the two curves intersect.

It has been shown that ASME Code,Section XI, Appendix K [2] acceptance criteria have been satisfied for Levels C and D Service Loadings based on the following:

(1) Figure 9-5 and Figure 9-6 show that with a factor of safety of 1.0 on loading, the applied J-integral (J1 ) is less than the J-integral of the material at a ductile flaw extension of 0.10 inch (J0 .1) for both the upper and lower transition welds. From Table 9-1 and Table 9-3, the ratio J0.1/Jj is 810/257, or 3.15 at the upper transition weld. Table 9-2 and Table 9-4 show that this ratio is 841/178, or 4.73, at the lower transition weld. These ratios are well above the Code required value of 1.0.

(2) Figure 9-5 and Figure 9-6 show that with a factor of safety of 1.0 on loading, flaw extensions are ductile and stable at both weld locations since the slope of the applied J-integral curve is less than the slopes of both the lower bound and mean J-R curves at the points of intersection.

(3) Figure 9-7 and Figure 9-8 demonstrate that the applied J-integrals peak at flaw extensions well less than 75% of the vessel wall thickness for both the upper and lower transition welds. Furthermore, from Table 9-5 and Table 9-6, the minimum pressure at tensile instability for flaws at the two transition welds is 4987 psi, which is well above the maximum pressure of 2185 psi during the hot leg LOCA transient.

Page 69

For Information Only Document No. 32-9195651-000 A NON - PROPRIETARY AREVA Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary

11.0 REFERENCES

1. U.S. Code of Feeral Regulations, Title 10, "Domestic Licensing of Production and Utilization Facilities," Appendix G to Part 50, "Fracture Toughness Requirements," Federal Register, April 12, 2012.

2. ASME Boiler and Pressure Vessel Code,Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components," Division 1, 2007 Edition with 2008 Addendum.

3. U.S. Code of Federal Regulations, Title 10, "Domestic Licensing of Production and Utilization Facilities," Part 50.55a, "Codes and Standards," Federal Register, April 12, 2012.

4. ANSYS Finite Element Computer Code, Version 12.1, ANSYS Inc., Canonsburg, PA.

5. S. Chapuliot, M.H. Lacire, and P. Le Delliou, "Stress-Intensity Factors for Internal Circumferential Cracks in Tubes over a Wide Range of Radius over Thickness Ratios", Fatigue, Fracture, and High Temperature Design Methods in Pressure Vessels and Piping, pp.95-106, PVP-Vol. 365, 1998 ASME/JSME Joint Pressure Vessels and Piping Conference, San Diego, California, July 26-30, 1998.

6. AREVA Document 18-1149327-004, "Functional Specification for Reactor Coolant System for Davis Besse."

7. AREVA Document 32-1174278-007, "Verification of PCRIT 6.3 & User's Manual."

8. J. A. Keeney and T. L. Dickson, "Stress-Intensity-Factor Influence Coefficients for Axially Oriented Semielliptical Inner-Surface Flaws in Clad Pressure Vessels (Ri/t=10)," Oak Ridge National Laboratory, ORNL/NRC/LTR-93/33, Revision 1, September 1995.

9. AREVA Document 32-1204037-01, "Low Upper-Shelf Toughness Fracture Analysis - Turkey Point 3&4."

10. AREVA Document 32-5017465-003, "Low Upper-Shelf Toughness Fracture Analysis, Davis-Besse."

11. AREVA Drawing 02-154615E-09, "Material List Head & Vessel."

12. AREVA Document BAW-2313-006, "B&W Fabricated Reactor Vessel Materials and Surveillance Data Information."

13. ASME Boiler and Pressure Vessel Code,Section II, Part D, "Properties (Customary) -

Materials," 2007 Edition with 2008 Addendum.

14. AREVA Document 32-9017744-004, "Davis-Besse ART Values at 52 EFPY."

15. AREVA Document 32-9123247-000, "RTPTS Values of Davis-Besse Unit 1 for 52 EFPY, Including Extended Beltline."

16. AREVA Document NPGD-TM-500, Rev. D, "NPGMAT-NPGD Materials Properties Program User's Manual," March 1985.

17. AREVA Document 32-1164462-000, "Toledo 1/2 Loop Seism ic Analysis and ARS Generation."

18. AREVA Drawing 02-154617E-001, "Shell Assembly and Head Details."

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For Information Only Document No. 32-9195651-000 A

AREVA NON - PROPRIETARY Equivalent Margins Assessment of Davis Besse Transition Welds for 52 EFPY - Non- Proprietary

19. AREVA Drawing 02-104176E-001, "Upper Shell Forging."

20. AREVA Drawing 02-154623E-003, "Vess el Head Assembly."

21. AREVA Drawing 02-154616E-004, "Upper Shell Assembly."

22. AREVA Drawing 02-104184D-000, "Lower Head Forging."

23. U.S. Nuclear Regulatory Commission, Regulatory Guide 1.99, Revision 2, "Radiation Embrittlement of Reactor Vessel Materials," May 1988.

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