ML022670644

E-mail Attaching BAW-2323, Low Upper-Shelf Toughness Fracture Mechanics Analysis of Reactor Vessels of Surry Units 1 & 2 for Extended Life Through 48 Effective Full Power Years.

ML022670644
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Site:	Surry
Issue date:	08/22/2002
From:	Henig M Dominion Generation
To:	Office of Nuclear Reactor Regulation
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BAW-2323
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Omid Tabatabai - BAW-2323 ____________Page I]

• 12-From: <MichaelHenig@dom.com>

To: <OTY@nrc.gov>

Date: 08/22/2002 8:16:17 AM

Subject:

BAW-2323 (Embedded image moved to file: pic29288.pcx)

Omid, Attached is BAW-2323 [i.e., LOW UPPER-SHELF TOUGHNESS FRACTURE MECHANICS ANALYSIS OF REACTOR VESSELS OF SURRY UNITS 1 AND 2 FOR EXTENDED LIFE THROUGH 48 EFFECTIVE FULL POWER YEARS] for your information in support of the NRC Staff reactor vessel embrittlement evaluation.

Should you have any questions, please advise, (See attached file: BAW-2323.pdf)

Michael W. Henig Phone: 804-273-2237 Fax: 804-273-3554 CC: <BillCorbin@dom.com>, <JuliusWroniewicz@dom.com>, <DavidRoth@dom.com>,

<DavidHostetler@dom.com>, <PaulAitken@dom.com>, <David_Lewis@shawpittman.com>,

<Tom Snow@dom.com>, <DianeAitken@dom.com>, <MarcHotchkiss@dom.com>,

<LillianCuoco@dom.com>, <Nitin_Shah@dom.com>

[]

I BAW-2323 Jurs 1998 I

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LOW UPPER-SHELF TOUGHNEIS7 i FRACTURE MECHANICS ANALYSIS I OF REACTOR VESSELS OF SURRY UNITS 1 AND 2 I FOR EXTENDED LIFE THROUGH I 48 EFFECTIVE FULL POWER YEARS I

FRAMATOME TEC H NO LOG I ES

BAW-2323 June 1998 LOW UPPER-SHELF TOUGHNESS FRACTURE MECHANICS ANALYSIS OF REACTOR VESSELS OF SURRY UNITS 1 AND 2 FOR EXTENDED LIFE THROUGH 48 EFFECTIVE FULL POWER YEARS FTI Document No. 77-2323-00 Framatome Technologies, Inc.

Integrated Nuclear Services P. 0. Box 10935 Lynchburg, VA 24506-0935

LOW UPPER-SHELF TOUGHNESS FRACTURE MECHANICS ANALYSIS OF REACTOR VESSELS OF SURRY UNITS 1 AND 2 FOR EXTENDED LIFE THROUGH 48 EFFECTIVE FULL POWER YEARS BAW-2323 FTI Document No. 77-2323-00 Prepared for Virginia Power Company by Framatome Technologies, Inc.

Lynchburg, Virginia This report is an accurate description of the low upper-shelf toughness fracture mechanics analysis performed for the reactor vessels at Surry Units I and 2 g

D. E. Killian, Principal Engineer Date Materials and Structural Analysis Unit This report has been reviewed and found to be an accurate description of the low upper-shelf toughness fracture mechanics analysis performed for the reactor vessels at Surry Units 1 and 2.

rJ' K. K. Yoon /hnical Consultant Date Materials arXStructural Analysis Unit Verification of independent review.

E. Moore, Manager Date Materials and Structural Analysis Unit This report is approved for release.

6)2s! 7 D. L. Howell, Project Manager Date Reactor Vessel Services ii

EXECUTIVE

SUMMARY

Since it has been projected that the upper-shelf Charpy energy levels of reactor vessel beltine weld materials at Surry Units 1 and 2 may be less than 50 ft-lb at 48 effective full power years of service, a low upper-shelf fracture mechanics evaluation is required to demonstrate that sufficient margins of safety against fracture remain to satisfy the requirements of Appendix G to 10 CFR Part 50.

A low upper-shelf fracture mechanics analysis has been performed to evaluate the reactor vessel welds at Surry Units I and 2 for ASME Levels A, B, C, and D Service Loadings, based on the evaluation acceptance criteria of the ASME Code,Section XI, Appendix K.

The analysis presented in this report demonstrates that the reactor vessel beltline welds at Surry Units I and 2 satisfy the ASME Code requirements of Appendix K for ductile flaw extensions and tensile stability using projected low upper-shelf Charpy impact energy levels for the weld material at 48 effective full power years or plant operation.

iii

CONTENTS Section Heading Page "1. Introduction .................................................................................................................. 1-1

2. Acceptance Criteria ...................................................................................................... 2-1 2.1 Levels A and B Service Loadings (K-2200) ........................................................... 2-1 2.2 Level C Service Loadings (K-2300) ....................................................................... 2-2 2.3 Level D Service Loadings (K-2400) ...................................................................... 2-2

3. Material Properties and Reactor Vessel Design Data .................................................. 3-1 3.1 J-Integral Resistance Model for Mn-Mo-Ni/Linde 80 Welds ................................... 3-1 3.2 Material Properties for Weld Material ..................................................................... 3-2 3.3 Reactor Vessel Design Data .................................................................................. 3-3 3.4 J-Integral Resistance for Linde 80 W eld Material .................................................. 3-3

4. Analytical Methodology ................................................................................................ 4-1 4.1 Procedure for Levels A and B Service Loadings .................................................... 4-1 4.2 Procedure for Levels C and D Service Loadings ................................................... 4-5 4.3 Temperature Range for Upper-Shelf Fracture Toughness Evaluations ................. 4-5 4.4 Effect of Cladding Material ..................................................................................... 4-6

5. Applied Loads ............................................................................................................. 5-1 5.1 Levels A and R Service Loadings .......................................................................... 5-1 5.2 Levels C and D Service Loadings .......................................................................... 5-1

6. Evaluation for Levels A and B Service Loadings ......................................................... 6-1

7. Evaluation for Levels C and D Service Loadings ......................................................... 7-1

8. Summary of Results ..................................................................................................... 8-1

9. Conclusion ................................................................................................................... -1

10. References ................................................................................................................ 10-1 iv

LIST OF TABLES Page Table 3-1 Mechanical Properties for Beltline Materials .......................................................... 3-2 Table 3-2 Selected Welds and Properties ....................................................................... 3-4 Table 3-3 J-Integral Resistances for Levels A and B Service Loadings ................................. 3-5 Table 3-4 J-Integral Resistances for Levels C and D Service Loadings ............................. 3-5 Table 6-1 Flaw Evaluation for Levels A and B Service Loadings ........................................... 6-2 Table 6-2 J-Integral vs. Flaw Extension for Levels A and B Service Loadings ...................... 6-3 Table 6-3 J-R Curves for Evaluation of Levels A and B Service Loadings ............................ 6-4 Table 7-1 K, vs. Crack Tip Temperature for SLB .................................................................... 7-4 Table 7-2 KI, at 1/10 Wall Thickness ..................................................................................... 7-5 Table 7-3 Kj. at 1/jo Wall Thickness with Aa = 0.10 in ............................................................ 7-6 Table 7-4 J-Integral vs. Flaw Extension for Levels C and D Service Loadings ...................... 7-7 Table 7-5 J-R Curves for Evaluation of Levels C and D Service Loadings ............................ 7-8 LIST OF FIGURES Page Figure 1-1 Reactor Vessel Beltline Materials for Surry Unit 1 ................................................. 1-2 Figure 1-2 Reactor Vessel Beltline Materials for Surry Unit 2 .......... ....................... 1-3 Figure 2-1 Reactor Vessel Beltline Region with Postulated Longitudinal Flaw ........... 2-4 Figure 2-2 Reactor Vessel Beitline Region with Postulated Circumferential Flaw .............. 2-4 Figure 5-1 Surry Steam Line Break without Offsite Power Transient ...................................... 5-2 Figure 6-1 J-Integral vs. Flaw Extension for Levels A and B Service Loadings ...................... 6-5 Figure 7-1 K, vs. Crack Tip Temperature for SLB .................................................................... 7-9 Figure 7-2 J-Integral vs. Flaw Extension for Levels C and D Service Loadings .................... 7-10 v

1. Introduction One consideration for extending the operational life reactor vessels beyond their original licensing period is the degradation of upper-shelf Charpy impact energy levels in reactor vessel materials due to neutron radiation. Appendix G to 10 CFR Part 50, "Domestic Licensing of Production and Utilization Facilities," states in Paragraph IV.A.l.a that, "Reactor vessel beltline materials must have Charpy upper-shelf energy ... of no less than 75 ft-lb initially and must maintain Charpy upper-shelf energy throughout the life of the vessel of no less than 50 ft-lb, unless it is demonstrated in a manner approved by the Director, Office of Nuclear Reactor Regulation, that lower values of Charpy upper-shelf energy will provide margins of safety against fracture equivalent to those required by Appendix G of Section Xl of the ASME Code."

Materials with Charpy upper-shelf energy below 50 ft-lbs are said to have low upper-shelf (LUS) fracture toughness. Fracture mechanics analysis is necessary to satisfy the requirements of Appendix G to 10 CFR Part 50 for reactor vessel materials with upper-shelf Charpy impact energy levels that have dropped, or that are predicted to drop, below the 50 ft-lb requirement.

The base metal and weld materials used in the beltline regions of the Surry Units 1 and 2 reactor vessels are identified in Figures 1-1 and 1-2, respectively. Since it has been projected that the upper-shelf Charpy energy levels of the beltine weld materials may be less than 50 ft-lb at 48 effective full power years (EFPY's) of service, a low upper-shelf fracture mechanics evaluation has been performed to satisfy the requirements of Appendix G to 10 CFR Part 50.

A similar analysis is not required for the reactor vessel beltline forging materials since all applicable materials are predicted to have upper-shelf Charpy energy levels in excess of 50 ft-lb at 48 EFPY.

The present analysis addresses ASME Levels A, B, C, and D Service Loadings. For Levels A and B Service Loadings, the low upper-shelf fracture mechanics evaluation is performed according to the acceptance criteria and evaluation procedures contalned in Appendix K to Section Xl of the ASME Code [1]. The evaluation also utilizes the acceptance criteria prescribed in Appendix K for Levels C and D Service Loadings, although evaluation procedures for this class or loading conditions are not specified In the Code. Levels C and D Service Loadings are evaluated using the one-dimensional, finite element, thermal and stress models and linear elastic fracture mechanics methodology of Framatome Technologies' PCRIT computer code to determine stress intensity factors for a worst case pressurized thermal shock transient.

1-1

Figure 1-1 Reactor Vessel Beltline Materials for Surry Unit 1 J726 (Rotterdam) Weld Weld SA-1494 Intermediate Shell (Plate) C4326-1 & C4326-2 Weld SA-1585 Inside 40%

SA-1650 Outside 60%

Weld SA-1494 Weld SA-1526 Lower Shell (Plate) C4415-1 &C4415-2 1-2

Figure 1-2 Reactor Vessel Beltline Materials for Surry Unit 2 L737 (Rotterdam) Weld Weld SA-1585 Weld WF-4 Inside 50%

SA-1585 Outside 50%

Intermediate Shell (Plate) C4331-2 & C4339-2 R3008 (Rotterdam) Weld Weld WF-4 Weld WF-4 Inside 63%

WF-8 Outside 37%

Lower Shell (Plate) C4208-2 & C4339-1 1-3

2. Acceptance Criteria Appendix G to Section XI of the ASME Code [1] provides analytical procedures for the prevention of non-ductile fracture in those areas of the pressure boundary that are comprised of materials with upper-shelf Charpy energy levels of at least 50 ft-lbs. These procedures utilize transition range fracture toughness curves with a fluence-based adjustment to crack tip temperature, and require that the component be operated at a sufficiently low pressure so as to preclude non-ductile failure. These same procedures, however, make no allowance when crack-tip temperatures are maintained above the transition range between cleavage and ductile type failures, where ductile tearing is the predicted mode of failure for ferritic reactor vessel materials. Accordingly, additional evaluation procedures were developed that utilize elastic-plastic fracture mechanics methodology and the concept of J-integral controlled crack growth. Added to Section Xl of the ASME Code as Appendix K, these new analytical guidelines may be applied when crack tip temperatures are in the upper-shelf temperature region.

Acceptance criteria for the assessment of reactor vessels with low upper shelf Charpy energy levels are prescribed in Article K-2000 of Appendix K to Section XI of the ASME Code [1].

These criteria, which apply to both longitudinal and circumferential flaws, as depicted in Figures 2-1 and 2-2, respectively, 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.

2-1

2.2 Level 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 in., 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.

2.3 Level 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.

2-2

Figure 2-1 Reactor Vessel Beltline Region with Postulated Longitudinal Flaw

-Semi.Elliptical Flaw (Not to scale:)

2-3

Figure 2-2 Reactor Vessel Beitline Region with Postulated Circumferential Flaw Semi-Elliplical Flaw (not to soale) 2-4

3. Material Properties and Reactor Vessel Design Data An upper-shelf fracture toughness material model is presented below, as well as mechanical properties for the weld material and reactor vessel design data.

3.1 J-Integral Resistance Model for Mn-Mo-Ni/Linde 80 Welds A model for the J-integral resistance versus crack extension curve (J-R curve) required to analyze low upper-shelf energy materials has been derived specifically for Mn-Mo-Ni/Linde 80 weld materials. The toughness model was developed from a large data base of fracture specimens, as described in the report for a low upper-shelf analysis performed for reactor vessels at Florida Power and Light's Turkey Point Units 3 and 4 [2]. Using a modified power law to represent the J-R curve, the mean value of the J-integral is given by:

4 J = 1000 C I (Aa)c2 exp(C3 AaC )

with In(C1) = al + a2Cu(0,),7 +a3 T+a4 In(BN)

C2= dl+d2 ln(C1)+d3 ln(BN)

C3 = d4 + d5 ln(CI) + d6 ln(B N)

C4 = -0.4489 where Aa = crack extension, in.

Cu = copper content, Wt-%

01 = fluence at crack tip, 1018 n/cm 2 T = temperature, OF BN = specimen net thickness = 0.8 in.

and al = 1.81 a2 = -1.512 a3 = -0.00151 a4 = 0.3935 a7 = 0.1236 dl = 0.077 d2 = 0.1164 d3 = 0.07222 d4 = -0.08124 d5 = -0.00920 d6 = 0.05183 3-1

A lower bound (-2S.) J-R curve is obtained by multiplying J-integrals from the mean J-R curve by 0.699 [2]. It was shown in Reference 1 that a typical lower bound J-R curve is a conservative representation of toughness values for reactor vessel beltline materials, as required by Appendix K [1] 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.

3.2 Material Properties for Weld Material Mechanical properties are developed in Table 3-1 for the following materials:

Reactor vessel base metal: A533, Grade B, Class 1 low alloy steel plate

Description:

Mn-1/2Mo-1/2Ni Carbon content: < 0.30%

Description of weld material:

Weld wire: Mn-Mo-Ni Weld fluxes: Linde 80, SAF 89, and Grau Lo Note: Although the J-R upper-shelf fracture toughness model was developed specifically for Linde 80 weld material, it is assumed that this material model may be used for all beltline welds, including the Rotterdam J276, L737, and R3008 weld materials.

Table 3-1 Mechanical Properties for Beltline Materials Temp. G Yield Strength (Sy) Ultimate Strength (Su) Alpha Base Base Surry-1 Surry-2 Base Surry-1 Surry-2 Base Metal Metal Weld Weld Metal Weld Weld Metal Code Code Actual Actual Code Actual Actual Code

[3] [3] [4] [4] [3] [4] [4] [3]

(F) (ksi) (ksi) (ksi) (ksi) (ksi) (ksi) (ksi) (in/in/F) 100 29500 50.0 65.1 65.1 80.0 81.0 81.0 7.06E-06 200 28800 47.5 61.8 61.8 80.0 81.0 81.0 7.25E-06 300 28300 46.1 60.0 60.0 80.0 81.0 81.0 7.43E-06 400 27700 45.1 58.7 58.7 80.0 81.0 81.0 7.58E-06 500 27300 44.5 57.9 57.9 80.0 81.0 81.0 7.70E-06 543 27000 44.2 57.5 57.5 80.0 81.0 81.0 7.76E-06 600 26700 43.8 57.0 57.0 80.0 81.0 81.0 7.83E-06 Also, Poisson's ratio, v, is taken to be 0.3.

3-2

The ASME transition region fracture toughness curve for K*, used to define the beginning of the upper-shelf toughness region, is indexed by the RTNDT of the weld material. Using Table 3 3 of Reference 5 for generic Linde 80 weld material, the mean and standard deviation of the initial RTNDT are -4.8 OF and 19.7 OF, respectively.

3.3 Reactor Vessel Design Data Pertinent design data for upper-shelf flaw evaluations in the beltline region of the reactor vessel are provided below for Surry Units I and 2.

Design pressure, Pd = 2485 psig (use 2500 psig)

Inside radius, Ri = 78.95 in.

Vessel thickness, t = 8.08 in.

Cladding thickness, t, = 0.16 in.

Reactor coolant inlet temperature, Tin= 543 OF 3.4 J-Integral Resistance for Linde 80 Weld Material Values of J-integral resistance from the upper-shelf toughness model of Section 3.1 are dependent on the temperature and fluence at the crack tip location, and the copper content of the weld material. These parameters are listed below for the reactor vessels at Surry Units 1 and 2.

Crack tip temperature varies with plant operation. At normal conditions, the temperature at the crack tip, T, is taken to be the inlet temperature, or Crack tip temperature, T = Tin = 543 OF Fluence at the crack tip is derived from the inside surface fluence using the attenuation equation from Regulatory Guide 1.99, Rev. 2 [6]:

e- 4x w h ere where 2

ot = attentuated fluence at crack tip, n/cm 0s = fluence at inside surface, n/cm2 x = depth into the vessel wall, in.

3-3

Table 3-2 lists the copper content of the weld materials and the fluence at the inside surface of the reactor vessel for all welds located within the innermost 40% of the beltline wall.

Table 3-2 Selected Welds and Properties Weld Weld Copper Inside Surface Plant ID Orientation Content Fluence (wt-%) (n/cm 2)

Surry 1 J726 Circumferential 0.33 9.92 x 1018 SA-1494 Longitudinal 0.16 11.0 x 1018 SA-1585 Circumferential 0.22 51.7 x 1018 SA-1526 Longitudinal 0.34 11.0 x 1018 Surry 2 L73' Circumferential 0.35 9.42 x 1018 SA-1585 Longitudinal 0.22 13.0 x 1018 WF-4 Longitudinal 0.19 13.0 x 1018 R3008 Circumferential 0.19 58.7 x 10"'

Tables 3-3 and 3-4 provide mean and lower bound J-integral resistances, J01 , of the weld material at a ductile flaw extension of 0.10 in. This data is provided for the beltline region weld locations at Surry Units I and 2, based on the following postulated flaw depths for Levels A&B and C&D Service Loadings:

Service Flaw Depth Extension Total Depth Loading a Aa x = a + Aa Condition (in.) (in.) (in.)

Level A&B t/4 = 2.02 0.1 2.12 Level C&D t110 = 0.808 0.1 0.908 3-4

Table 3-3 J-Integral Resistances for Levels A and B Service Loadings Weld Weld Fluence Lower Plant ID Orient. at Extended Mean Bound Crack Depth J0.1 J0.1 (n/cm2) (lb/in) (Ib/in)

Surry 1 J726 C 5.96 x 10l 816 570 SA-1494 L 6.61 x 1018 1020 713 SA-1585 C 18 31.1 x 10 884 618 SA-1526 L 6.61 x 1018 801 560 Surry 2 L737 C 5.66 x 10'8 797 557 SA-1585 L 7.82 x 1018 935 654 WF-4 L 7.82 x 1018 975 681 R3008 C 35.3 x 1018 924 646 Table 3-4 J-Integral Resistances for Levels C and D Service Loadings Plant ID Orient. at Extended Mean Bound Crack Depth J0 .1 J0.1 2

(n/cm ) (lb/in) (lb/in)

Surry 1 J726 18 C 7.98 x 10 803 561 SA-1494 L 8 8.85 x 10' 1012 708 SA-1585 C 41.6 x 101 " 873 610 SA-1 526 L 8.85 x 1018 787 550 Surry 2 L737 C 7.58 x 1018 784 548 SA-1585 L 10.5 x 101" 925 647 WF-4 L 10.5 x 1018 966 675 R3008 C 47.2 x 10'8 913 639 3-5

4. Analytical Methodology Upper-shelf toughness is evaluated using fracture mechanics analytical methods that utilize the acceptance criteria and evaluation procedures of Section Xl, Appendix K [1], where applicable.

4.1 Procedure for Levels A and B Service Loadings The applied J-Integral is calculated per Appendix K, paragraph K-4210 [11, using an effective flaw depth to account for small scale yielding at the crack tip, and evaluated per K-4220 for upper-shelf toughness and per K-4310 for flaw stability, as outlined below.

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

K = (SF)p(1 +- )(z]a)°"F where

], =0.982+1.006 7a2 0.20<*i *0.50 (2) 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:

K,, = (SF)pI +-- L)" F2 where 0.8 8 5 + 0.2 3 3 (a +0 345 , 0.20_<

020 < 0.50

• 050) 4-1

(3) For a longitudinal or circumferential flaw of depth, a, the stress intensity factor due to radial thermal gradients is calculated using the following:

=K CR 25 0:< (CR) 1000 F / hour where (CR) = cooldown rate (°F / hour)

-7.435 (a F3= 0.690+3.127 +3.532(j), 0.20* a _<0.50 (4) The effective flaw depth for small scale yielding, a, is calculated using the following:

"IFK7PKI,12 ae ai=a+ . .

(5) For a longitudinal flaw of depth a, the stress intensity factor due to internal pressure for small scale yielding is calculated with a safety factor (SF) on pressure using the following:

-,, (SF)1 4 Ij where F,' = 0. 982 + 1.006 a, 2 0.20 !9 < 0.50 4-2

(6) For a circumferential flaw of depth ae, the stress intensity factor due to internal pressure for small scale yielding is calculated with a safety factor (SF) on pressure using the following:

K- (SF)1 4 I++/-Ri ,)Q"FO where F2 = 0.885 + 0 .2 3 3 a, 0.345 2, 0.20 _< tL < 0.50 (7) For a longitudinal or circumferential flaw of depth, a, the stress intensity factor due to radial thermal gradients for small scale yielding is calculated using the following:

KI, CR 10 00)* 2t.5F, "3 , 0*< (CR) 100° F/hour where F3' =0.690+3.127( -7.435 + 3.532 a. 0.20:5 < 0.50 (8) The J-integral due to applied loads for small scale yielding is calculated using the following:

J, = 1000 E' where E 2 1- v 4-3

(9) Evaluation of upper-shelf toughness at a flaw extension of 0.10 in. is performed for a flaw depth, a = 0.251 + 0.10in.,

using SF = 1.15 p=P.

where P, is the accumulation pressure for Levels A and B Service Loadings, such that J, <J0.,

where J, = the applied J-integral for a safety factor of 1.15 on pressure, and a safety factor of 1.0 on thermal loading J0.1 = the J-integral resistance at a ductile flaw extension of 0.10 in.

(10) 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 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 facLor (SF) on pressure Is 1.25. Flaw stability at a given applied load is verified when 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 where the two curves intersect.

4-4

4.2 Procedure for Levels C and D Service Loadings Levels C and D Service Loadings are evaluated using the one-dimensional, finite element, thermal and stress models and linear elastic fracture mechanics methodology of the PCRIT computer code to determine stress Intensity factors for pressurized thermal shock type transient events.

The evaluation is performed as follows:

(1) Utilize PCRIT to calculate stress intensity factors for a semi-elliptical depth flaw depth of 1/10 the base metal wall thickness, as a function of time, due to internal pressure and radial 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.

(2) 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 points of intersection.

4.3 Temperature Range for Upper-Shelf 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, K1j, in lower-shelf and transition regions. In the upper shelf region, the upper-shelf toughness curve, Kj,, is derived from the upper-shelf J-integral resistance model described in Section 3.1. 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 K4 and the upper-shelf toughness curves, is considered.

4-5

4.4 Effect of Cladding Material Although the PCRIT code utilized in the flaw evaluations for Levels C and D Service Loadings has a built-in cladding model to include the effect of thermal expansion in the claddina on stress, the code does not consider stresses in the cladding when calculating stress intensity factors for thermal loads. To account for this cladding effect, an additional stress intensity factor, Kiclad, is calculated separately and added to the total stress intensity factor computed by PCRIT.

The contribution of cladding stresses to stress intensity factor was examined previously [7] for the Zion-1 WF-70 weld using thermal loads for the Turkey Point SLB without offsite power transient. The maximum value of Kiclad, at any time during the transient and for any flaw depth, was determined to be 9.0 ksi'lin. Since the Zion, Turkey Point, and Surry reactor vessels are similar in design, this value for I<cad will also be used for the present flaw evaluations.

4-6

5. Applied Loads The Levels A and B Service Loadings required by Appendix K are an accumulation pressure (internal pressure load) and a cooldown rate (thermal load). Since Levels C and D Service Loadings are not specified by the Code, Levels C and D pressurized thermal shock events are reviewed and a worst case transient is selected for use in flaw evaluations.

5.1 Levels A and B Service Loadings Per paragraph K-1300 of Appendix K [1], the accumulation pressure used for flaw evaluations should not exceed 1.1 times the design pressure. Using 2.5 ksi as the design pressure, the accumulation pressure is 2.75 ksi. The cooldown rate is also taken to be the maximum required by Appendix K, 100 OF/hour.

5.2 Levels C and D Service Loadings The limiting Level D transient for the Surry plants is the main steam line break (SLB) without offsite power transient. Pressurizer pressure and cold leg temperature variations for this transient are shown in Figure 5-1. The pressures used in the PCRIT transient analysis are increased by 30 psi over those defined in Table 5-1 to account for the pressure difference between the pressurizer and the downcomer (i.e., reactor vessel beltline region). The PCRIT analysis of this transient was of sufficient duration to capture the peak value of stress intensity factor over time. Since this transient bounds all Level C transients [7], it is also used to evaluate Level C Service Loadings.

5-1

Pressurizer Pressure, psi 2500 2000 1500 1000 500 0 100 200 300 400 500 600 Transient Time, sec.

Cold Leg Temperature, F 600 500 400 300 200 100 0

0 100 200 300 400 500 600 Transient Time, sec.

Figure 5-1 Surry Steam Line Break without Offsite Power Transient 5-2

6. 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 4.1 and evaluated for acceptance based on values for the J-integral resistance of the material from Section 3.4. The results of the evaluation are presented in Table 6-1, where it is seen that all welds satisfy the acceptance criterion based on J-resistance at a flaw extension of 0.10 in.; i.e., the ratio of material J-resistance to applied J-integral, J0 .1/J 1 , must be greater than 1. From Table 6-1, the minimum value of J0 .1/J 1 is 1.19 (for the longitudinal weld SA-1526 at Unit 1).

The flaw evaluation for the controlling weld (SA-1526 at Unit 1) is repeated by calculating applied J-integrals for various amounts of flaw extension with safety factors (on pressure) of 1.15 and 1.25 in Table 6-2. The results, along with mean and lower bound J-R curves developed in Table 6-3, are plotted in Figure 6-1. An evaluation line at a flaw extension 0.10 in. is utilized to confirm the results of Table 6-1 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. The requirement for ductile and stable crack growth is also demonstrated by Figure 6-1 since the slope of the applied J-integral curve for a safety factor of 1.25 is less than the slope of the lower bound J-R curve at the point where the two curves intersect.

6-1

Table 6-1 Flaw Evaluation for Levels A and B Service Loadings Dimensional data: Material data:

Ri = 78.95 in. T= 543 F t= 8.08 in.

E= 27000 ksi ao = 2.0200 in. nu= 0.3 da = 0.1000 in.

a= 2.1200 in.

a/t = 0.2624 (0.2 < a/t < 0.5)

Loading data: Geometry factors for initial flaw depth (wlo plasticity correction):

Pd = 2.50 ksi F1 = 1.0513 for pressure loading and axial flaws Pa = 2.75 ksi F2 = 0.9699 for pressure loading and circumferential flaws SF 1.15 F3 = 1.0624 for thermal loading and both flaw types CR= 100 F/hr Plant Weld Orient. Kip J(0.1) J(0.1)/

Kit Sy ae ae/t F1'/F2' F3' Kip' Kit' JI at t/4 JA (ksi4in) (ksi'lin) (ksi) (in.) (ksi4in) (ksi4in) (lb/in) (Ib/in)

Surry 1 J726 C 46.59 19.72 57.5 2.1905 0.2711 0.9735 1.0617 47.53 19.70 152 570 3.74 SA-1494 L 92.41 19.72 57.5 2.3217 0.2873 1.0651 1.0584 97.98 19.64 466 713 1.53 SA-1585 C 46.59 19.72 57.5 2.1905 0.2711 0.9735 1.0617 47.53 19,70 152 818 4.06 SA-1526 L 92.41 19.72 57.5 2,3217 0.2873 1.0651 1.0584 97.98 19.64 466 560 1.20 Surry2 L737 C 46.59 19.72 57.5 2,1905 0.2711 0.9735 1.0617 47.53 19,70 152 557 3.66 SA-1585 L 92.41 19.72 57.5 2.3217 0.2873 1.0651 1.0584 97.98 19.64 466 654 1.40 WF-4 L 92.41 19.72 57.5 2.3217 0.2873 1.0651 1.0584 97.98 19.64 466 681 1.46 R3008 C 46.59 19.72 57.5 2.1905 0.2711 0.9735 1.0617 47.53 19.70 152 646 4.24 6-2

Table 6-2 J-Integral vs. Flaw Extension for Levels A and B Service Loadings Ri = 78.95 in. Pa = 2.75 ksi Note: This check on flaw stability per K-431C is performed t= 8.08 in. CR = 100 F/hr for the limiting weld (Longitudinal SA-1526 at Surry 1).

ao = 2.020 in. Sy = 57.5 ksi SF = 1.15 1.15 S

Aa a KIp Kit ae Kip' Kit' J1 Alln 4

Kip Kit ae Kip' Kit' JA (in.) (in.) (ksi'in) (ksi4in) (in.) (ksiqin) (ksiq/in)

. o fh1=n/ (ksiWin) (ksi4in) (in.) (ksiqin) (ksiqin) (lb/in) 0.000 2.020 89.66 19.71 2.2120 94.95 19.70 443 97.46 19.71 2.2403 104.05 19.68 516 0.025 2.045 90.35 19.72 2.2394 95.71 19.69 449 98.21 19.72 2.2681 104.89 19.67 523 0.050 2.070 91 t04 19.72 2.2668 96.46 19.67 455 98.95 19.72 2.2960 91.73 105.73 19.66 530 0.075 2.095 19 RA ,,frt 9.3 19.72 2.2943 9722 QRR Af 99.70 19.72 2.3238 106.56 19.64 537 0.100 2.120 92.41 19.72 2.3217 97.98 19.64 466 100.45 19.72 2.3517 107.40 19.62 544 0.125 2.145 93.10 19.71 2.3492 98.74 19.62 472 101.20 19.71 2.3796 108.24 19.60 551 0.150 2.170 93.79 19.71 2.3767 99.51 19.60 478 101.95 19.71 2.4075 109.09 19.58 558 0.175 2.195 94.48 19.70 2.4042 100.27 19.58 484 102.70 19.70 2.4354 109.93 19.56 565 0.200 2.220 95.17 19.69 2.4317 101.03 19.56 490 103.45 19.69 2.4633 110.78 19.53 572 0.225 2.245 95.86 19.68 2.4592 101.80 19.53 496 104.20 19.68 2.4912 111.62 19.50 579 0.250 2.270 96.55 19.67 2.4867 102.57 19.51 502 104.95 19.67 2.5192 112.47 19.47 587 0.275 2.295 97.24 19.66 2.5143 103.34 19.48 508 105.70 19.66 2.5471 113.32 19.44 594 0.300 2.320 97.93 19.64 2.5418 104.11 19.45 515 106.45 19.64 2.5751 114.18 19.41 601 0.325 2.345 98.63 19.63 2.5694 104.88 19.41 521 107.20 19.63 2.6031 115.03 19.37 609 0.350 2.370 99.32 19.61 2.5970 105.66 19.38 527 107.96 19.61 2.6311 115.89 19.33 616 0.375 2.395 100.01 19.59 2.6245 106.43 19.34 533 108.71 19.59 2.6591 116.75 19.30 624 0.400 2.420 100.71 19.57 2.6521 107.21 19.31 539 109.47 19.57 2.6872 117.61 19.25 631 0.425 2.445 101.40 19.55 2.6797 107.99 19.27 546 110.22 19.55 2.7152 118.48 19.21 639 0.450 2.470 102.10 19.52 2.7074 108.77 19.22 552 110.98 19.52 2.7433 119.34 19.17 647 0.475 2.495 102.80 19.50 2.7350 109.56 19.18 559 111.74 19.50 2.7714 120.21 19.12 654 0.500 2.520 103.50 19.47 2.7626 110.35 565 112.50 19.47 2.7994 121.09 19.07 662 I 19.14 565 112.50 19.47 2.7994 121.09 19.07 662 6-3

Table 6-3 J-R Curves for Evaluation of Levels A and B Service Loadings Weld: Longitudinal SA-1526 at Surry I T= 543 F t= 8.08 in.

ao = 2.02 in.

psurf = 11.0 10A18 n/cm^2 @ inside surface Cu = 0.34 Bn = 0.80 in Aa a t InCl Cl C2 C3 J-R (Ib/in)

(in.) (in.) 2 1 0 1B n/cm ) Mean Low 0.001 2.0210 6.7724 0.25107 1.28540 0.09011 -0.09511 83 58 0.002 2.0220 6.7708 0.25109 1.28542 0.09011 -0.09511 156 109 0.004 2.0240 6,7675 0.25113 1.28547 0.09012 -0.09511 251 176 0.007 2.0270 6.7627 0.25118 1.28555 0.09012 -0.09511 340 238 0.010 2.0300 6.7578 0-25124 1.28562 0.09013 -0.00511 400 280 0.015 2.0350 6.7497 0.25134 1.28575 0.09014 -0.09512 471 329 0.020 2.0400 6.7416 0.25144 1.28587 0.09015 -0.09512 521 364 0.030 2.0500 6.7254 0.25163 1.28612 0.00017 -0.09512 592 414 0.040 2.0600 6.7093 0.25182 1.28637 0.09020 -0.09512 643 449 0.050 2.0700 6.6932 0.25201 1.28661 0.09022 -0.09512 682 477 0.070 2.0900 6.6612 0.25240 1.28711 0.09026 -0.09513 740 517 0.100 2.1200 6.6134 0.25298 1.28786 0.09033 -0.09513 801 560 0.120 2.1400 6.5817 0.25336 1.28835 0.09038 -0.09513 831 581 0.140 2.1600 6.5502 0.25375 1.28885 0.09042 -0.09514 857 599 0.160 2.1800 6.5188 0.25413 1.28934 0.09047 -0.09514 880 615 0.200 2.2200 6.4566 0.25490 1.29033 0.09056 -0.09515 917 641 0.250 2.2700 6.3795 0.25586 1.29157 0.09067 -0.09516 954 667 0.300 2.3200 6.3034 0.25682 1.29281 0.09078 -0.09517 984 688 0.350 2.3700 6.2282 0.25778 1.29405 0.09089 -0.09517 1010 706 0.400 2.4200 6.1540 0.25873 1.29529 0.09100 -0.09518 1032 722 0.450 2.4700 6.0806 0.25968 1.29652 0.09111 -0.09519 1052 735 0.500 2.5200 6.0080 0.26064 1.29776 0.09122 -0.09520 1070 748 6-4

Figure 6-1 J-Integral vs. Flaw Extension for Levels A and B Service Loadings J-Integral (lb/in) 1200

---.- J-R Mean J-R Lower Bound

- - - Jappi w/ SF=1.25 1OO00 ..... Jappl w/SF = 1.15 Evaluation Line for SF= 1.15 800 600 400 200 0

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

6-5

7. Evaluation for Levels C and D Service Loadings A flaw depth of 1/1o the base metal wall thickness is used to evaluate the Levels C and D Service Loadings. Based on the results of Table 6-1 for Levels A and B Service Loadings and flaw depths equal to 114 of the wall thickness, the controlling weld for Levels C and D Service Loadings is the SA-1526 longitudinal weld at Unit 1.

Table 7-1 presents applied stress intensity factors, K1, from the PCRIT pressurized thermal shock analysis of the steam line break transient described in Section 5.2, along with total stress intensity factors after including a contribution of 9.0 ksihin from cladding, as discussed in Section 4.4. The stress intensity factor calculated by the PCRIT code is the sum of thermal, residual stress, deadweight, and pressure terms. Table 7-1 also shows the variation of crack tip temperature with time for the SLB event. To determine the critical time in the transient for the Level C and D flaw evaluation, allowable stress intensity factors are calculated for both the transition and upper-shelf toughness regions. Transition region toughness is obtained from the ASME Section XI equation for crack initiation [8],

K10 = 33.2 + 2.806 exp[O.02(T - RTNDT + 100°F)]

using an RTNDT value of 281.6 OF from PCRIT for a flaw depth of 1/10 the wall thickness, where:

Kic = transition region toughness, ksibin T crack tip temperature, 'F Upper-shelf toughness is derived from the J-integral resistance model of Section 3.1 for a flaw depth of 1/10 the wall thickness, a crack extension of 0.10 in., and a fluence value of 8.8 x 1018 n/cm 2, as follows:

FJý 0 1E KjC = 1000 1- V2 )

where Ki, = upper-shelf region toughness, ksi/in J0.1 = J-integral resistance at Aa = 0.1 in.

Toughness values are given in Tables 7-2 and 7-3 for the transition and upper-shelf regions, respectively, as a function of temperature.

7-1

Figure 7-1 shows the variation of applied stress intensity factor, K,, transition toughness, K1c, and upper-shelf toughness, Kj, with temperature. The small rectangles on the K, curve indicate points in time at which PCRIT solutions are available. In the upper-shelf toughness range, the K, curve is closest to the lower bound Kj, curve at 7.0 minutes in the transient. This time is therefore used as the critical time in the transient at which a postulated flaw of 1/lo the base metal wall thickness is evaluated for Levels C and D Service Loadings.

Applied J-integrals are calculated for the controlling weld (SA-1526 at Unit 1) for various flaw depths in Table 7-4 using stress intensity factors from PCRIT for the steam line break transient (at 7.0 min.) and adding 9.0 ksi4in to account for cladding effects. Stress intensity factors are converted to J-integrals by the plane strain relationship, K-tot 1(a)

Jappi~ed(a) = 1000 (1- v 2 )

Flaw extensions from an initial flaw depth of 1/10 the wall thickness are determined by subtracting 0.775 in. from the built-in PCRIT flaw depths. The results, along with mean and lower bound J-R curves developed in Table 7-5, are plotted in Figure 7-2. An evaluation line is 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 [1]. The requirements for ductile and stable crack growth are also demonstrated by Figure 7-2 since the slope of the applied J integral curve is considerably less than the slopes of both the lower bound and mean J-R curves at the points of intersection.

Referring to Figure 7-2, the Level D Service Loading requirement that the extent of stable flaw extension be no greater than 75% of the vessel wall thickness is easily satisfied since the applied J-integral curve intersects the mean J-R curve at a flaw extension that is only a small fraction of the wall thickness (less than 1%). Also, the remaining ligament would not be subject to tensile instability, as demonstrated below by conservatively postulating an infinitely long longitudinal flaw and calculating the collapse pressure for a flaw depth equal to 1/10 the wall thickness plus 0.10 in.

Consider:

a remaining ligament, c = t - (t/10 + 0.10) =8.08 - (8.08/10 + 0.10) = 7.172 in.,

a radius to the crack tip, R 0 = Ri + t/10 + 0.10 = 78.95 + 8.08/10 + 0.10 = 79.858 in.,

and a yield strength, cy = 57.5 ksi.

The collapse pressure, Pc, defined as the pressure required to produce net section yielding, can be found by equating the average hoop stress in the remaining ligament to the yield strength, as follows:

PRdc = cy 7-2

Then Pr = ca^RC = (7.172 in.)(57.5 ksi)/(79.858 in.) = 5.16 ksi which is greater than any postulated accident condition pressure.

7-3

Table 7-1 KI vs. Crack Tip Temperature for SLB aft =1/10 a = 0.808 in.

PCRIT Clad Total Time Temp Klsum KI KI 0.00 544.0 48.3 9.0 57.3 0.25 543.4 45.7 9.0 54.7 0.50 536.2 41.0 9.0 50.0 0.75 523.2 43.6 9.0 52.6 1.00 509.7 48.3 9.0 57.3 1.50 486.7 55.9 9.0 64.9 2.00 467.5 62.2 9.0 71.2 2.50 450.0 67.8 9.0 76.8 3.00 434.5 72.1 9.0 81.1 3.50 421.2 75.7 9.0 84.7 4.00 409.7 78.6 9.0 87.6 4.50 399.3 81.1 9.0 90.1 5.00 390.0 83.1 9.0 92.1 5.50 382.0 84.6 9.0 93.6 6.00 375.0 85.7 9.0 94.7 6.50 368.7 86.6 9.0 95.6 7.00 363.0 87.3 9.0 96.3 7.50 357.7 87-9 9.0 96.9 8.00 353.1 88.2 9.0 97.2 9.00 345.3 88.4 9.0 97.4 10.00 330.3 88.5 9.0 97.5 7-4

Table 7-2 K, at 1/jo Wall Thickness KIc Curve at a = 1/1OT RTndt 278.2 F T T-RTndt Kic (F) (ksi*in) 200 -78.2 37.5 210 -68.2 38.5 220 -58.2 39.7 230 -48.2 41.1 240 -38.2 42.9 250 -28.2 45.0 260 -18.2 47.6 270 -8.2 50.8 280 1.8 54.7 290 11.8 59.5 300 21.8 65.3 310 31.8 72.4 320 41.8 81.0 330 51.8 91.6 340 61.8 104.6 350 71.8 120.4 360 81.8 139.7 370 91.8 163.2 380 101.8 192.0 390 111.8 227.2 400 121.8 270.1 410 131.8 322.6 420 141.8 386.7 430 151.8 464.9 440 161.8 560.5 450 171.8 677.3 7-5

Table 7-3 Ki, at 1/lo Wall Thickness with Aa = 0.10 in.

KJc Curve with Aa = 0.10 in.

Fluence = 11.0 x 10A18 n/cmA2 at inside surface

= 8.8 x 10A18 n/cmA2 at t/l0 + 0.1" Aa= 0.10 in.

Cu = 0.34 Wt-%

E = 27000 ksi nu = 0.30 C4 = -0.4489 Lower Lower Mean Bound Mean Bound T InCI CI C2 C3 J(O.1) J(0.1) KJc KJc (F) (lb/in) (lb/in) (ksi-Iin) (ksi'in) 200 0.74714 2.11095 0.14785 -0.09967 1135 793 183.5 153.4 250 0.67164 1.95745 0.13906 -0.09898 1076 752 178.7 149.4 300 0.59614 1.81510 0.13028 -0.09828 1020 713 174.0 145.5 350 0.52064 1.68310 0.12149 -0.09759 967 676 169.4 141.6 400 0.44514 1.56071 0.11270 -0.09690 917 641 164.9 137.9 450 0.36964 1.44721 0.10391 -0.09620 869 608 160.6 134.3 500 0.29414 1.34197 0.09512 -0.09551 824 576 156.4 130.7 550 0.21864 1.24438 0.08633 -0.09481 781 546 152.3 127.3 600 0.14314 1.15389 0.07755 -0.09412 741 518 148.3 124.0 7-6

Table 7-4 J-Integral vs. Flaw Extension for Levels C and D Service Loadings Time = 7.0 min. E= 27000 ksi Crack tip at t/10 t= 8.08 in. nu = 0.3 (a/t)*40 a Aa Temp. Klsum Klclad Kltotal Japp (in.) (in.) (F) (lb/in) 1 0.2020 318.8 49.4 9.0 58.4 115 2 0.4040 334.1 68.3 9.0 77.3 201 3 0.6060 348.8 79.6 9.0 88.6 265 4 0.8080 0.0000 363.0 87.3 9.0 96.3 313 5 1.0100 0.2020 376.6 92.8 9.0 101.8 349 6 1.2120 0.4040 389.6 96.7 9.0 105.7 377 7 1.4140 0.6060 402.0 99.6 9.0 108.0 398 8 1.6160 0.8080 413.7 101.8 9.0 110.8 414 9 1.8180 1.0100 424.8 103.5 9.0 112.5 427 10 2.0200 1.2120 435.3 104.5 9.0 113.5 434 12 2.4240 1.6160 454.3 105.5 9.0 114.5 442 14 2.8280 2.0200 470.9 105.3 9.0 114.3 440 16 3.2320 2.4240 485.0 105.5 9.0 114.5 442 18 3.6360 2.8280 497.0 105.0 9.0 114.0 438 20 4.0400 3.2320 507.0 104.0 9.0 113.0 430 22 4.4440 3.6360 515.2 102.7 9.0 111.7 421 24 4.8480 4.0400 521.8 101.3 9.0 110.3 410 20 5.2520 4.4440 527.1 10U.0 9.0 109.0 400 28 5.6560 4.8480 531.2 98.4 9.0 107.4 389 30 6.0600 5.2520 534.4 96.7 9.0 105.7 377 32 6.4640 5.6560 536.8 94.9 9.0 103.9 364 Note: At Aa = 0.10 in., Japp = 331 lb/in 7-7

Table 7-5 J-R Curves for Evaluation of Levels C and D Service Loadings Weld. Longiludiawl SA-1520 at Surry 1 Time = 7.00 min.

T= 363.0 F t = 8.08 in.

ao = 0.808 in.

Fsurf = 11.0 1 0^1 8 n/cmA2 @ inside surface Cu = 0.34 Bn = 0.80 in Aa a Fl InCl Cl C2 C3 J-R (lb/in)

(in.) (in.) 1018 n/cm2 ) Mean Low 0.001 0.8090 9.0588 0.49903 1.64712 0.11897 -0.09739 83 58 0.002 0.8100 9.0566 0.49905 1.64716 0.11897 -0.09739 161 113 0.004 0.8120 9.0523 0.49909 1.64722 0.11898 -0.09739 267 187 0.007 0.8150 9.0458 0.49915 1.64732 0.11899 -0.09739 370 259 0.010 0.8180 9.0392 0.49921 1.64742 0.11899 -0.09739 441 308 0.015 0.8230 9.0204 0.49931 1,04759 0.11900 -0.09739 526 368 0.020 0.8280 9.0176 0.49941 1.64775 0.11902 -0.09740 589 411 0.030 0.8380 8.9960 0.49961 1.64808 0.11904 -0.09740 678 474 0.040 0.8480 8.9744 0.49981 1.64841 0.11905 -0.09740 743 520 0.050 0.8580 8.9529 0.50001 1.64874 0.11909 -0.09740 794 555 0.070 0.8780 8.9100 0.50041 1.64940 0.11913 -0.09740 871 609 0.100 0.9080 8.8461 0.50101 1.65039 0.11920 -0.09741 954 667 0.120 0.9280 8.8037 0.50141 1.65105 0.11925 -0.09741 996 696 0.140 0.9480 8.7616 0.50181 1.65171 0.11930 -0.09742 1032 722 0.160 0.9680 8.7196 0.50221 1.65236 0.11934 -0.09742 1064 744 0.200 1.0080 8.6363 0.50300 1.65368 0.11943 -0.09743 1116 780 0.250 1.0580 8.5333 0.50400 1.65533 0.11955 -0.09744 1170 818 0.300 1.1080 8.4315 0.50499 1.65697 0.11967 -0.09745 1214 848 0.350 1.1580 8.3309 0.50598 1.65862 0.11978 -0.09746 1251 875 0.400 1.2080 8.2316 0.50697 1.66026 0.11990 -0.09746 1284 898 0.450 1.2580 8.1334 0.50796 1.66190 0.12001 -0.09747 1313 918 0.500 1.3080 8.0364 0.50895 1.66354 0.12013 -0.09748 1340 937 7-8

Figure 7-1 KI vs. Crack Tip Temperature for SLB KI (ksi'4in) 180 160 I

I!

140 120

/~ -- - KIc

./ ,I....Kjc Mean I -- Evaluation point at 100 _ / 7.0 min. into transientKcLoeBun __ LeBu E -E--- KI at a = 1 /10OT for SLB

- .Upper Shelf Limit 80 60 40 20 Upper-Shelf Toughness Range 0

340 365 390 415 440 465 490 515 540 Crack Tip Temperature (F) 7-9

Figure 7-2 J-Integral vs. Flaw Extension for Levels C and D Service Loadings J-Integral (lb/in) 1400 1200 1000 800

_J-R Lower Bound 600

--- Japplied for SLB at 7.0 mi.

-Evaluation Line for Level C

__-_ -o-e-C Lin e 400 70 - - -

200 0

00.00 0.10 0.20 0.30 0.40 0.50 Flaw Extension, Aa (in.)

7-10

8. Summary of Results A low upper-shelf fracture mechanics analysis has been performed to evaluate reactor vessel welds at Surry Units 1 and 2 for projected low upper-shelf energy levels at 48 EFPY, considering Levels A, B, C, and D Service Loadings of the ASME Code.

Evidence that the ASME Code, Section Xl, Appendix K [1] acceptance criteria have been satisfied for Levels A and B Service Loadings is provided by the following:

(1) Figure 6-1 shows that with a factors of safety of 1.15 on pressure and 1.0 on thermal loading, the applied J-integral (J 1) is less than the J-integral of the material at a ductile flaw extension of 0.10 in. (Jo.1). The ratio Jo.1/J 1 = 1.20 which is greater than the required 1.0.

(2) Figure 6-1 shows that with a factors of safety of 1.25 on pressure and 1.0 on thermal loading, flaw extensions are ductile and stable since the 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.

Evidence that the ASME Code,Section XI, Appendix K [1] acceptance criteria have been satisfied for Levels C and D Service Loadings is provided by the following:

(1) Figure 7-2 shows 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 in. (Jo. 1). The ratio Jo.1/J1 is 2.02, which is greater than the required 1.0.

(2) Figure 7-2 shows that with a factor of safety of 1.0 on loading, flaw extensions are ductile and stable since the 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 7-2 shows that flaw growth is stable at much less than 75% of the vessel wall thickness. It has also been shown that the remaining ligament is sufficient to preclude tensile instability by a large margin.

8-1

9. Conclusion The Surry Unit 1 and 2 reactor vessel beltline welds satisfy the acceptance criteria of Appendix K to Section XI of the ASME Code [1] for projected low upper-shelf Charpy impact energy levels at 48 effective full power years of plant operation.

9-1

10. References

1. ASME Boiler and Pressure Vessel Code,Section XI, Division 1, 1992 Edition including December 1993 Addendum.

2. BAW-2118P, Low Upper-Shelf Toughness Fracture Analysis of Reactor Vessels of Turkey Point Units 3 and 4 for Load Level A & B Conditions, November 1991.

3. ASME Boiler and Pressure Vessel Code,Section III, Division 1, Appendices, 1986 Edition.

4. BAW-2150, Materials Information for Westin ghouse-Designed Reactor Vessels Fabricated by B&W, December 1990.

5. BAW-1803, Rev. 1, Correlations for Predicting the Effects of Neutron Radiation on Linde 80 Submerged-Arm Welds, May 1991.

6. U.S. Nuclear Regulatory Commission Regulatory Guide 1.99, Revision 2, May 1988.

7. BAW-2178P, Low Upper-Shelf Toughness Fracture Mechanics Analysis of Reactor Vessels of B&W Owners Reactor Vessel Working Group for Level C & D Service Loads, February 1993

8. Marston, T.U., Flaw Evaluation Procedures: ASME Section XI, Report NP-719-SR, Electric Power Research Institute, Palo Alto, California, August 1978.

10-1