ML20207B227

Rev 0 to SIR-99-021, Evaluation of Stratification Loadings in LBB Analysis for Mnps,Unit 2 Surge Line

ML20207B227
Person / Time
Site:	Millstone
Issue date:	02/22/1999
From:	Chesworth S, Cofie N, Deardorff A STRUCTURAL INTEGRITY ASSOCIATES, INC.
To:
Shared Package
ML20207B214	List: B17682, Responds to NRC Re Licensee Request for Review & Approval of LBB Methodology for Plant Pressurizer Surge Piping.Rev 0 to SIR-99-021, Evaluation of Stratification Loadings in LBB Analysis for Mnps,Unit 2 Surge Line, Encl ML20207B227
References
SIR-99-021, SIR-99-021-R00, SIR-99-21, SIR-99-21-R, NUDOCS 9903080045
Download: ML20207B227 (44)

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3 Docket No. 50-336 B17682-f Attachment 2 Millstone Nuclear Power Station,- Unit No. 2 Response to Request For Additional Information Concerning Leak Before Break Evaluation of the Pressurizer Surge Piping Response to RAI Question 2 Report SIR-99-021, Rev. 00 Evaluation Of Stratification Loading in Leak Before Break Analysis For Millstone Nuclear Station, Unit 2 Pressurizer Surge Line February 1999 February 1999 9903080045 990226 PDR P ADOCK PDR 05000336\

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Report No.: SIR-99-021 Revision No.: 0 Project No.: NUSCO-22Q File No.: NUSCO-22Q-404 February 1999 Evaluation of Stratification Loadings in Leak-Before Break Analysis for Millstone Nuclear PowerStation Unit 2 Surge Line 1

4 Preparedfor:

Northeast Utilities (Contract # 02063726) I Prepared by:

StructuralIntegrity Associates,Inc.

San Jose, California Prepared by:

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f eardorff, P .

Date: NE2l$9 '

Prepared by: Date: 2N2 /M

[f . .C ,Ph.D. /

Reviewed b Date: I h9 S.T Chesworth Approved by: N Date: Tl22}94

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f StructuralIntegrityAssociates,Inc.

s REVISION CONTROL SHFET -

Document Number: SIR-99-021. Rev. O

Title:

Evaluation of Stratification Loadings In Leak-Before-Break Analysis for  :

Millstone Nuclear Power Station. Unit 2 Surge Line Client: Northeast Utilities SI Project Number: NUSCO-220 Section Pages Itevision Date Comments  ;

0 2/22/99 Initial Issue f

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4 Table of Contents Section Page I .0 I NT R O D U CT I O N .. . ....... .... ...... ... .... .... ...... .... ... .. ..... . . ............ ... ....... ... ................. .. 1 - 1 2.0 QUESTION #2 - CONSIDERATION OF STRATIFICATION LOADINGS... ....... 2-1 3.0 RES PO NS E TO Q UESTI O N #2: ........................................................................... ....... 3- 1 3.1 Re view of S trati fication Loadi ngs... ..... ..... ... ....... .................... ............... .. ...... .. .. 3- 1 3.2 Evaluation of Loadings at All Locations.... ................................................3-2

3. 3 Leak age S i ze Fl a ws . . . . . . . . . . ... . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . 3-3 3.4 M at e ri al Prope rt ies . . . .. .. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . .. . ... . 3-4 3.5 C ri t ic al Fl a w S i zes . . . . . . . . . . . . . . .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .. . . . .. . . . . . . . . . . . . .. . . . .. . .... . . 3 -5 4.0 C O N C L U S I O NS . . . . .. ....... .... .... . . .... .... . ...... ....... .. ...... ...... ... .. .. . ... ... .. .... ...... ..... .............. ....... 4- 1 5.'O R E FE R E N C ES . . . ... . ... . . . .. . . . . .. .. . .. . . . . .. .. . . . . . .. . . . . . . . . . . . . . ..... .. .. .. . . .. . ..

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! Eagt Iakls i Table 3 1 Initial Heatup Stratification Loads and Stresses (Case 1)(AT = 3407, l

! Pressurimr Temp. - 4107, RCS Temp. = 707, Presswe = 262 psig) .............. .. 3-7 Table '2-2 Intermediate Pressure Cooldown Stratification Loads and Stresses (Case 2) (AT '

= 2427, Presswimr Temp. = 576T, RCS Temp. = 3347, Pressure - 1270 paig).. 3-8 l

Table 3-3 Initial Cooldown Stratification Loads and Stresses (Case 3)(AT = 1707, ,

l i Pressmizer Temp. = 6537, RCS Temp. = 483T Presswe = 2235 psig) . .... .. ... 3-9 ,

. Table 3-4 Normal OaerW Stratification Loads and Stresses (Case 4) (AT = 497,

! Pressurizer Temp = 6537, Hot Leg Temp.= 604T, Presswe = 2235 psig)..... . 3 ,

Table 3 5 - Initial Cooldown Stratification Loads and Stresses (Case 5)(AT = 2107, -

l Pressuizer Temp. - 6107, RCS Temp. = 400T, Pressure = 1645 psig) .. ........ 3-11 Table 3-6 Initial Cooldown Stratificatio.n Loads and Stresses (Case 6) (AT = 295T, i Pressurizer Temp. = 495T, RCS Temp. = 200T, Pressure = 635 psig) . . .......... 3 l Table 3-7 Normal Operating Condition Stresses without Stratification (AT = 01, '

i Pressurizer Temp. = 653T, Hot Leg Temp. = 6044, Pressure = 2235 psig) ...... 3  ;

l Table 3-8 Evalmdan of Stress Ratios for Strad&ation Cases at AllImcations........ ..... ... 3-14 1 Table 3-9 10gpm Leakage Flaw Length and Area for Case 4 AT = 497 (Pr===d= .

l Temp. = 653T, RCS Temp. = 6047, Pressurc = 2235 psig). ... ................... ._. 3 l Table 3-10 Material Properties for A105, Grade II Nozzle .. .......... ..... ........ ....-....... .. 3-16 i Table 3 11 Material Properties for SMAW Weld Metal ... ..... .............. ...... ..................... 3-17 Tabic 3-12 Material Properties of the A351 CF8M Cast Stainless Steel Spool Pieces of the

' Surge Line at 70T...... ..................... ...... .... ....... ....... ............ .... ............. . 3 - 18 Table 3-13 Matenal Properties of the A351 CF8M Cast Stainless Steel Spool Pieces of the  :

l 4 Surge Line at3347.....................................................................3-19 Table 3 14 Material Properties of the A351 CF8M Cast Stainless Steel Spool Pieces of the Surge Line at4837...........................................................................................3-20  !

i Table 3-15 Summary of Material Properties for Cast Stainless Steel at 6054..... ..... .......... 3-21 j Table 3-16 Material Properties of the A351 CF8M Cast Stainless Steel Low Yield Spool '

l i Piece At Node 2 for 2007 and 400T .... ...... ............ .................................. ... .. 3-22 '

l Table 3-17 Critical Flaw Sizes for Case I with AT = 340T (Pressurizer Temperatwe

= 410T, RCS Temperature = 707 Pressure = 262 psig) ............... ...... . .. 3-23 i >

j Table 3-18 Critical Flaw Sizes for Case 2 with AT= 2427 (Presswizer Temperature

= 576T, RCS Temperature 3347, Pressure = 1270 psig).......... ..... .................. 3-24 )

Table 3 19 Critical Flaw Sizes for Case 3 AT= 1707 (Pressurizer Temperature

= 653*F RCS Temperature 483T, Pressure = 2235 psig).. ................................. 3-25 J Table 3-20 Comparison of Critical and 10pm Flaws for Critical Weld Location............. 3 26 ,

l Table 3-21 Critical Flaw Sizes Based on 42 Factor on Normal Plus SSE Loads I

(All Locations are A351 CF8M Cast Stainless Stee...................................

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Table 3-22 Critical Flaw Size Comparison for Case 5 with AT = 210T (Pressurizer i Temperature - 6104, RCS Temperature 400T, Pressure = 1645 psig) ...... ...... 3-28 Table 3-23 Critical Flaw Size Comparison for Case 6 with AT = 2954 (Pressurizer l Temperatwe = 4957. RCS Temperature 2001, Pressure = 635 psig) .. ............. 3-28 i

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List af Figures Figure Pace Figure 3-1. Surge Line Piping Materials and Node Identification.......... .. .. ....... ............. . 3-29 Figure 3-2. Locations for Evaluation at Hot Leg Nozzle..... . ..... ...................... . . . . . . . . . . . . . .. . . . 3 -3 0 Figure 3-3. Maximum Pressurizer Temperature as a Function of RCS Temperature.. ........... 3-31 1

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1.0 INTRODUCTION

The NRC has completed a review of the information provided in the Northeast Nuclear Energy Company (NNECO) November 9,1998 submittal requesting approval of leak-before-break status for the Millstone Unit 2 surge line. Questions were submitted based on Structural Integrity Associates (SI) report SIR-98-096 [1], an enclosure to the November 9,1998, submittal letter.

This report provides a response to Question 2 from the NRC request for additional information

! dated 1/11/99 included in Section 2.0. The evaluation, addressing all issues requested,is i provided in Section 3.0. Conclusions are in Section 4.0. References are cited in Section 5.0.

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2.0 ' QUESTION #2 - CONSIDERATION OF STRATIFICATION LOADINGS '

The following is the question from the 1/11/99 request for additional information:

• I The guidance that has been denloped on Leak-Before-Break by the NRC stafin NUREG-1061,

Volume 3 and in Draft Standard Review Plan Section 3.6.3 (MRP 3.6.3) indicates that seural sources ofloading should be considered when evaluating leakagejaw andcriticalyaw sizes.

' These sources include internalpressure, piping deadweight, thermal expansion, the safe shutdown earthquake (ME), andseismic anchor motion. De intent ofthese loading analyses was to examine the loadt which would cause leakagefaw to open under normal operation

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(NOP) conditions and to examine the loads which could cause the criticalfaw tofall under the assumedbounding case of(NOP+%E).

l When the guidance in NUREG-1061 Volume 3 amiDSRP 3.6.3 was developed, application of l

- LBB to PWR surge lines was not explicitly considered and the occurrence ofthermal stratifcation in surge lines was not widely known. Howewr, in reviewing other submittals to apply LBB to PWR surge lines, the NRCstaf'sposition has been that like thermal expansion i loads, loadt due to thermal stratifcation must be considered.

Provide thefollowing analyses to supplementpour November 9,1998 submittal:

(1) Evaluate the impact ofincluding the thermal stratifcation loads at normal operatfor:

j (100percentpower) when determining the leakagefaw sises (or explain why the assunprions made inyour Nowmber 9 assessment lead to a bounding analysis). Provide {

! the loads ()brces and moments) which were included in determining the leakageflaw sizes. Ifsome ofthe loading components (e.g. the deadweight loads) have not changed \

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l simply reference the information previously submitted butprovide a summation ofall

? loads which were included in this analysis.

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(2) Evaluate the criticalflaw sises (considering both the criterlafor a margin of2 between 1 the critical andleakagefaw sizes and the criteria based on a margin of,[2 on the loads)

A when startup and cooldown thermalstrats) cation loads are considered This evaluation should consider Ihe largest temperature diferences which could develop between the reactor coolant system hot leg and the pressurizer based on a review station startup and cooldown operatingprocedures. However, because ofthe extremelylowprobability of having a SSE concurrent with startup or cooldown transients, it is not necessary to include the SSEloads in this analysis.

As with question (1) abow, provide the loads which were included in the criticalfaw size analysis and a summation ofthese loads. Also indicate any otherfactors which were \

includedin the analysis. For example, when the time history ofthe startup or cooldown l i

transient is evaluated consideration ofthe actual system temperature (and the resulting material temperature) at the time when the largest temperature diference occurs may be used to evaluate the materials' tensile andfractureproperties. Alternatively, ifan SIR-99-021, Rev. 0 2-1 f 8tructuralhetentityAssociates,Inc.

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analysis is proposed to bound the conditions which actually occur at any time in the startup or cooldown transient, it should be explained why the assumptions made provide a bounding analysis.

Based on the NRC staff's independent evaluation of the materialprovided in the November 9, 1998 submittal and the telephone conference between the NRC, NNECO, and StructuralIntegrity Associates on December 21,1998, the staff expects that the limiting LBB analysis locationfor the Millstone Unit 2 surge line will be at node 2,16, or 13. Your response to this question should, at a minimum, address these locations, unless you identify another location which is more limiting in the course ofyour evaluation.

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I 3.0 - RESPONSE TO QUESTION'#2:

hi response to the request for supplemental evaluations, additional LBB evaluations and review i

of plant data have been conducted to assess the effects of themiai stratification. The following

! describes these additional evaluations.

3.1 Review of Stratification Loadings Review of plant operations showed that the most probable times of high AT in the surge line was for heatup operations. However, significant stratification can also occur during cooldown. For r this evaluation, six cases were considered to cover the range of conditions for heatup and

! cooldown.

l Case 1_- initial Heatup l During heatup, the pressurizer must be heated to about 400 F before the reactor coolant pumps -

l (RCPs) are brought on line. Prior to RCP Start, the reactor coolant temperature could be as low j as 70 F following a long period of plant shutdown conditions. Thus, a stratification condition of AT = 340 F was conservatively taken for initial heatup assuming that the pressurizer was at

. 410 F and that the reactor coolant system had cooled to 70 F. The associated pressure is 262 i

psig. When the reactor coolant pumps are started, the hot leg temperature rapidly increases, '

reducing the magnitude of the stratification AT. This case is also applicable to cooldown, except that this extremely low RCS temperature is not expected during cooldown.

1 Case 2 - Intennediate Pressure Cooldown During cooldown, it is generally quite easy to control the stratification, since the reactor coolant _

system is hot. Review of past operating history identified that a maximum stratification AT of 1 i

242 F was measured with pressurizer temperature of 576 F and hot leg temperature of 334*F.  !

The associated pressurizer pressure is 1270 psig. This case would also be applicable to heatup for the same reactor conditions.

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Case 3 - Initial Cooldown During initial phases of cooldown, stratification can develop. To assess this condition, the-maximum AT that would just meet LBB margins was determined to be AT = 170 F (pressurizer at 653"F and hot leg at 483*F). This AT was evaluated at normal operating pressure of 2235 -

psig. This would also be applicable as a limiting case for the end of heatup.

Case 4 - Normal Operating Conditions (NOC)

Maximum AT during normal plant operation is 49 F (pressurizer at 653 F, and hot leg at 604 F).

Pressurizer pressure is 2235 psig.

Cases 5 and 6 - Additional Intermediate Cases l Two additional intermediate cases were evaluated to determine the allowable pressurizer-to-hot leg temperature differential as a function of reactor coolant system temperature. These were:  :

Case 5: AT = 210 F, Hot Leg Temperature = 400*F, Pressurizer Temperature = 610 F  ;

(Pressure = 1645 psig)

Case 6: AT= 295 F, Hot Leg Temperature = 200*F, Pressurizer Temperature = 495 F (Pressure = 635 psig) f 3.2 Evaluation of Loadings at All Locations l

Tables 3-1 through 3-6 show the combined nodal moments and forces for each of the 1 4

1 l stratification cases, along with the nominal bending and tensile stresses due to axial forces and j l moments plus pressure. These were determined from the basic load tables in Appendix B of SIR-98-096. Nominal conditions without stratification are shown in Table 3-7. See Figure 3-1

for the definition of nodal locations.

i To determine the limiting locations for the additional evaluations, the nominal stresses at each of ~

the nodal locations were evaluated for the cases of normal operation (Case 4) with stratification and for the heatup (Case 1) and full pressure (Case 3) conditions. The results are shown in Table C +. See Figure 3-2 for the specific locations for Node 2. It is noted that the normal operating

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stresses near the hot leg nozzle (Nodes 2 and 3) are quite low for normal operation (Case 4).

Thus, large leakage size flaws result as reported in SIR-98-096. Stratification stresses for the maximum stratified flow cases result in a significant increase in stress at Nodal locations 2 and 3.

Thus, the ratio between the stratified condition stresses and the normal operating stratified stresses is large and these locations will be controlling for the stratification LBB cvaluation.

There is also a fair increase in stress at Node 16. Node 13 was also chosen for evaluation since it experiences very high stresses for normal operation plus stratification. By review of these tables, and the previous results in SIR-98-096, it is clear that evaluation of nodes 2,3,13, and 16 is sufficient to evaluate the effects of stratification loadings. Evaluation ofload cases 1 and 3 is sufficient for this determination since they represent the extremes of the stratification case AT's.

3.3 Leakage Size Flaws The leakage size flaws were re-evaluated under the assumption that stratification exists due to the normal operating temperature differential between the pressurizer and hot leg of 49 F (653 F

- 604 F). Since temperatures in the surge line observed in testirr [2] v,ere always less than the cold leg except for periods of significant pressurizer outsurge, the . leakage rate was calculated based on the hot leg temperature existing in the fluid and ::nterials at the leak location. This j assumption is further supported by the fact that normal pressurizer spray flow is only 1.5 gpm, l 1

whereas with 10 gpm leakage, most of the fluid would have to come from the hot leg. It was also observed that the resulting moments in the hot leg were always of a sign such that the

nomial + stratification stresses would be tensile on the bottom of the pipe, leading toward more tendency for relatively colder hot leg water to leak from the piping.

l Table 3-9 shows the calculated leakage size flaws and their associated leakage areas for normal operation (Case 4). The leakage flaw sizes were determined using the same methodology reported in SIR-98-096. Material properties are discussed in the following section.

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3.4 Material Properties The material properties for the surge line at nodes 2,3,13, and 16 were re-evaluated for the four stratification load cases with hot leg temperatures of 70"F,334"F,483*F and 604 F. In addition, properties for the cast austenitic stainless steel (CASS) were determined for 200 F and 400 F for the controlling locations (Nodes 2 and 3) for evaluation of Cases 5 and 6. The resulting material properties are shown in Tables 3-10 through 3-16.

For the A-105 Grade II hot leg nozzle, the generic lower bound stress-strain properties for carbon steel presented in SIR-98-096 were adjusted by the ratio of their values in the ASME Code Section III appendices, similar to the procedure used in Appendix A of SIR-98-096. The material J-resistance curve at 550*Fpresented in Appendix A of SIR-98-096 was conservatively used at the three temperatures of interest.

The spool specific stress-strain parameters for A351 CF8M centrifugal cast stainless steel (CASS) spool pieces were also adjusted per the ASME Code Section III appendices for use at the three temperatures used for critical flaw sizing. The procedure for determining the fracture toughness for the individual Millstone 2 surge line CF8M cast stainless steel spool pieces was provided in Appendix A of SIR-98-096. Correlations were provided for determining the J-R parameters for both normal operating and room temperature. A linear interpolation was used to determine the values of C and N at the intermediate temperatures of interest as shown in Tables 3-12 through 3-16.  ;

1 In determining the stress-strain parameters for the shielded metal arc weldments (SMAW) of the i surge line, values provided in Reference 3 at 75*F and 550 F for moderate strains (s 10%) were linearly interpolated in order to calculate the properties at the three temperatures of interest.

Also from Reference 3, it was determined that the J-R curve at 550*F is conservative compared to that of room temperature. The conservative parameters presented in SIR-98-096 were 1 therefore conservatively used for all the three temperatures of interest.

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t 3.5 Critical Flaw Sizes The critical flaw sizes for the Nodes 2,3,13 and 16 were calculated using the methodology outlined in SIR-98-096, Appendix C. The stresses associated with stratification cases (Cases 1 -

3) discussed above and presented in Tables 3-1 through 3-3 were used in the analysis. The material properties presented in Tables 3-10 through 3-14 were used to perform an clastic-plastic fracture mechanics analysis similar to tbt in Appendix C of SIR-98-096 to determine the critical flaw sizes at Nodes 2,3,13 and 16. The results of the analysis are shown in Tables 3-17 through 3-19. For Nodes 3,13 and 16, the evaluation only addressed the cast austenitic stainless steel since this material was shown to be limiting after review of SIR-98-096 and the current evaluation for Node 2.

l Table 3-20 provides a comparison between the critical flaw size that produces 10 gpm leakage at the critical weld locations. It can be seen that at all locations except Nodes 2 and 3, there is at least a margin of two between the critical flaw size and the 10 gpm leakage flaw size, thus satisfying the requirement of NUREG-1061, Volume 3. The two locations (2b, and 2c, cast stainless with low yield strength and 3, cast stainless with low yield strength) exhibited safety margins of 1.97 and 1.98 compared to the required margin of two. For all practical purposes, those two locations can be considered as having met the flaw size margin requirement in view of the conservatisms in the analysis. This confirms the earlier observation made based on the stress ratios that nodal locations 2 and 3 are the most critical.

It was shown in SIR-98-096 for all materials and locations that the flaw margin calculated based on a factor of unity on stress is more limiting than the margin calculated using 4 on normal plus SSE loads. To show that this was still the case for the stratification stresses, evaluations ,

were also performed at the most critical of all the locations shown in Table 3-17 through 3-19 (l.ocation 2b and 2c, cast stainless with low yield). The results are shown in Table 3-21. The evaluation confirmed that the one-half critical flaw sizes based on a factor of unity on stress were significantly smaller than the flaw sizes determined with a J2 factor on normal plus stratification stresses for the stratification loading conditions.

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To evaluate the sensitivity of two intermediate temperature conditions, Cases 5 and 6 were evaluated for Nodes 2 and 3 for the low yield strength cast austenitic stainless steel properties that exhibited the limiting flaw sizes and flaw size ratios for the other cases. Tables 3-22 and 3-23 show the results, showing that the flaw size margins are similar to the other cases evaluated.

Figure 3-3 shows the allowable pressurizer temperature as a function of hot leg temperature derived from all of the evaluations. The variation of allowable pressurizer temperature with hot leg temperature is almost a linear relationship over the range of operating temperatures up to the normal operating temperature of the pressurizer. Thus, the limiting pressurizer temperature defined by this figure may be used for any heatup and cooldown condition. So long as the pressurizer temperature (at any given hot leg temperature) does not exceed the curve, LBB ,

margins are satisfied.

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l Table 3-1 Initial Heatup Stratification Loads and Stresses (Case 1) j (AT = 3407, Pressurizer Temp. = 4107, RCS Temp. = 707, Pressure = 262 psig)

Moments,in Ib Nominal Stress,ksi Force,Ib Fx Fy Fz Mx My Mz SRSS kips Moment Node 556.1 6807.6 2337583 337889 634547 2445631 0.556 20.151 0.524 2 1543.6 53.8 6807.6 2220546 365671 606770 2330818 -6.808 19.205 0375 3 1543.6 l

-1118.9 6807.6 2185371 467539 606770 2315731 -6.808 19.081 0.37_5 4 1543.6 1621.3 6807.6 2160732 369966 582094 2268143 -1.387 18.688 0.504 5 1386 6 6903.6 2160732 475672 402006 2248696 1.387 18.528 0.504 7 -1386.6 2154.2

-2656.6 7662.4 2117425 -588634 358703 2226802 -7.662 18348 0354 8 -1386.6 3998.6 7662.4 2174289 -539850 358703 2268841 -7.662 18.694 0354 10 -525.7 7662.4 2209559 516610 349246 2295848 6373 18.9l7 0385 11 525.7 3831.0 7662.4 2328559 -347192 280469 2370948 -6373 19.535 0385 16 525.7 3129.3 8064.6 2627327 286406 107769 2645088 -6.825 21.794 0.374 13 -317.5 2340.0 8064.6 2514720 363999 83240 2542291 L.838 20.947 0.494 14 317.5 1837.6 2307082 363999 75065 2336826 1.380 19.254 0.504 15 -317.5 1380.1 8064.6

1) Loads are due to P + DW + SLTE + RCTE + TS P = Pressure DW = Dead Weight (Table B-1 of SIR-98-096)

SLTE = Surge Line Thermal Expansion (based on Mean of Pressurizer and Hot Leg Temperatures)(Table B 2)

RCTE = Reactor Coolant Loop Hot Leg Thermal Expansion (Table B-3 of SIR-98 0% Based on Hot Leg Temperature) .

TS = Thermal Stratification (Table B-4)

' 2) Stress due to bending is based on o = M / nrdt

3) See STR-98-096 Appendix D Section D.6 for methods of determining loads based on the unit load cases provided in Appendix B of SIR-98-096.

4) Example for Mx at Node 2 Basic L9.ad Multiplier Lsd Contribution DW l -43,321 -43,321 SLTE 174,450 53,100 (240-70)/(628.5-70) = 0.30439 RCTE (70-70y(604-70) = 0.0 -63,170 0 TS 340/96.34 - 3.5292 059,590 2.327.804 Total 2,337,583 SIR-99-021, Rev. 0 3-7 f StructuralIntegrityAssociatcs,Inc.

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Table 3-2 Intermediate Pressure Cooldown Stratification Loads and Stresses (Case 2)

(AT = 242*F, Pressurizer Temp. = 576*F, RCS Temp. = 334"F, Pressure = 1270 psig) 4 Force,Ib Moments,in-lb k ",I Nominal Stress, ksi Node Fx Fy Fz Mx My Mz SRSS kips Moment

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pg l 2 -6023.6 1806.3 14310.3 1702554 366828 498420 1811539 1.806 14.926 2.562 3 -6023.6 13G4 0 14310.3 1472970 475248 390000 1596121 -14.310 13.151 2.263 4 -6023.6 131.3 14310.3 15103'4 872790 390000 1795889 14.310 14.797 2.263 5 -4856.0 -371.1 702627 387831 1717249 4.856 14.149 2.489 14310 Q )*J n 7 -4856.0 -1039.1 14187A i518172 -1044835 348851 1875693 -4.856 15.455 2.489 8 -4856.0 -1541.5 15201.5 1494940 1231046 325622 1963759 15.202 16.180 2.242 10 -2290.5 3686.2 15201.5 i?69349 1046928 325622 19I4405 15.202 15.774 2.242 11 -2290.5 3518.6 15201.5 1601803 -989591 3169I9 I909320 -12.020 15.732 2.318 16 2290.4 2817.0 15201.5 1710120 -610830 254315 1833657 -12.020 15.108 2.318 4 13 -1668.2 2834.1 15551.6 1998297 788480 87741 2150021 12.634 17.715 2.303

14 1668.2 2331.7 15551.6 1758623 954564 34446 2001283 -2.332 16.490 2.549 15 -1668.2 1874.2 15551.6 1358189 954564 -8511 1660103 -1.874 13.678 2.560 f

1) Loads are due to P + DW + SLTE + RCTE + TS

P = Pressure  !

) DW = Dead Weight (Table B-1 of SIR-98-096)

SLTE = Surge Line Thermal Expansion (based on Mean of Pressurizer and i Hot Ixg Temperatures)(Table E-2)  !

RCTE = Reactor Coolant Loop Hot Leg Thermal Expansion (Table B-3 of l

, SIR-98-096 Based on Hot Leg Temperature) 1 TS = Thermal Stratification (Table B-4)

$ I

2) Stress due to bending is based on o = M / nr,2n t I

3) See SIR-98-096 Appendix D Section D.6 for methods of determii;ing loads based on the unit load cases provided in Appendix B of SIR-98-096.

j 4) Example for Mx at Node 2 i

Basic I Load Multiplier Load Contribution i

DW l -43,321 -43,321

! SLTE (455-70)/(628.5-70) = 0.68935 174,450 120,256 RCTE (334-70)/(604-70) = 0.49438 -63,170 -31,230 TS 242/96.34 = 2.51194 659,590 1 656.848 l Total 1,702,554 l

I l

S1R-99-021, Rev. 0 38' f StructuralIntegrityAssociates,Inc.

4 Table 3-3 Initial Cooldown Stratification Loads and Stresses (Case 3)

(AT= 170"F, Pressurizer Temp. = 653*F, RCS Temp. = 483*F, Pressure = 2235 psig) i Force, Ib Moments, in-lb ^**

p, Nominal Stress, ksi Node Fx Fy Fz Mx My- Mz A*

SRSS kips Moment pgrc l 2 8476.8 2564.4 18210.6 1227277 366501 389603 1338776 -2.564 11.031 4.523 3 -8476.8 2062.1 18210.6 941133 519076 237025 1100615 -18.211 9.069 4.149 q

'4 -8476.8 889.4 18210.6 1038520 1078521 237025 1515886 -18.211 12.490 4.149 j 5 -6746.4 387.0 18210.6 1050019 872186 248506 1387445 -6.746 11.432 4.423

7 6746.4 -314.4 17959.5 1050019 1342750 299597 1730687 6.746 14.260 4.423 8 -6746.4 -816.8 19080.4 1039833 -1564750 289413 1900909 19.080 15.663 4.129

! l0 -3261.I 3355.9 19080.4 1121886 1306622 289413 1746324 -I9.080 14.389 4.129 Ii -3261.I 3188.3 19080.4 II$1362 1231178 .28!509 1709000 14.894 14.081 4.229 16 -3261.0 2486.6 19080.4 1218380 -742567 225434 1469924 14.894 12.111 4.229 i

13 -2415.5 3026.4 19381.3 1513353 1057857 72274 1847843 -15.577 15.225 4.212 l ,

14 -2415.5 2524.0 19381.3 1207739 1270083 3797 1752643 -2.524 14.441 4.524

15 -2415.5 2066.5 19381.3 708686 1270083 -58400 1455595 -2.066 11.993 4.535 i

i

1) Loads are due to P + DW + SLTE + RCTE + TS 1

j P = Pressure .!

! DW = Dead Weight (Table B-1 of SIR-98-096)

SLTE = Surge Line Thermal Expansion (based on Mean of Pressurizer and l Hot Leg Temperatures)(Table B-2)

RCTE = Reactor Coolant Loop Hot Leg Thermal Expansion (Table B-3 of SIR-98-096 Based on Hot Leg Temperature)

TS = Thermal Stratification (Table B-4) l 2

i 2) Stress due to bending is based on o = M / nr t I

3) See SIR-98-096 Appendix D Section D.6 for methods of determining loads based on

the unit load cases provided in Appendix B of SIR-98-096.

1

4) Example for Mx at Node 2 .

i

\

Basic  ;

. Load Multiplier Load Contribution 2

DW. 1 -43,321 -43,321 3 SLTE (568-70)/(628.5-70) = 0.89167 174,450- 155,553 l RCTE (483-70)/(604-70) = 0.77341 -63,170 -48,856 TS 170/96.34 = 1.7646 659,590 1.163.902 Total 1,227,277-SIR-99-021, Rev. 0 3-9 gg,yggy,,g y,g,y,ggy pgggg;gggg, ing_

e

)

- & - i --- , y

r

~

Table 3-4 Normal Operating (NOC) Stratification Loads and Stresses (Case 4)

(AT = 49'F, Pressurizer Temp. = 653*F, Hot Leg Temp. - 604*F, Presst.re = 2235 psig) i Force, Ib Moments, in-lb Nominal Stress,ksl  ;

Mode Fx Fy Fz Mx My Ma SRSS kips Moment 7

l 10186.6 3377.0 20126.0 403437 303815 181388 536625 -3.377 4.422 4.504 2

3 -10186.6 2874.7 20126.0 97439 487166 -1970 496819 -20.126 4.094 4.104 4 4 -10186.6. 1702.0 20126.0 248464 1159457 -1970 1185782 -20.126 9.770 4.104 5 -8028.1 llW.6 20126.0 274583 94172G 24142 981232 -8.028 8.085 4393 7 -8028.1 631.1 19753.0 274583 -1497317 187463 1533785 -8.028 12.638 4.393_

20821.1 281420 -1727577 194302 1761100 -20.821 14.511 4.087 S -8028.1 128.8 25102 20821.1 361212 -1415237 194302 1476355 -20.821 12.164 4.0& }

10 -3954.1 Ii 3954.I 2342.6 20821.1 383069 -1332349 188440 1399073 -16.055 11.528 4.20l_

1640.9 20821.1 451167 -785636 149378 918150 -16.055 7.565 4.201 16 3954.0 ~

-2965.4 2858.2 21008.1 632758 1224196 44117 1378762 -16.711 11.360 4.185 13 14 -2965.4 2355.8 21008.1 295237 1459646 -32744 1489565 -2.356 12.273 4.528

-2965.4 1898.3 21008.1 -245716 1459646 109102 1484199 -1.898 12.229 4.539 15

1) Loads are due to P + DW , SLTE + RCTE + TS P = Presse e DW n Dead Weight SLTE - Surge Line Thermal Expansion (based on Mean of Pressurizer and Hot Leg Temperatures)(Table B-2)

RCTE = Reactor Coolant Loop Hot Leg Thermal Expansion (Table B-3 of SIR-98496 Based on Hot Leg TeWare) 1

= l TS Thermal Stratification (Table B-4)

2) Stress due to bending is based on a = M / stdt 1

i

3) See SIR-98-096 Appendix D Section D.6 for methods of determining loads based on the unit load cases provided in Appendix B of SIR-98-096.

4) Example for Mx at Node 2 Basic Lgad Multiolier LQAd Contribution DW 1 -43,321 -43,321 SLTE (628.5-70)/(628.5-70) - 1.0 174,450 174,450 RCTE (604-70)/(604-70) = 1.0 -63,170 -63,170 TS 49/96.34 = 0.$0862 659,590 335.478 Total 403,437 l

SIR-99-021, Rev 0 3 10 f StuctualIMenn4yAssociates,Inc.

_____..m _ -. _ . . . _ _ _ . _ . _ . _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ . _ _ . _ _ _ _ . _ _ _ _ _ _ _ _ _ _ . _ _ . _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

1

• i j

J 1

Table 3-5 Intermediate Temperature Stratification Loads and Stresses (Case 5)

(AT = 210"F, Pressurizer Temp. = 610"F, RCS Ternp. = 400"F, Pressure = 1645 psig) -

Force,Ib Moments, in-lb A**

pg Nominal Stress, Psi Node Fx Fy Fz Mx My Mz SRSS kips . Moment c

2 -7109.8 2142.5 16035.8 1491277 366576 450013 1600249 2.I42 13.I85 3.323 3 -7109.8 1640.2 16035.8 1236684 494546 322N2 1370283 -16.036 11.290 2.991 4 -7109.8 467.4 16035.8 1306217 963771 322042 1654922 -16.036 13.636 2.99I 5 -5692.9 -34.9 16035.8 1310124 777617 325926 1557992 -5.693 12.837 3.238 ,

7 -5692.9 -717.5 15856.1 I310124 -1176647 326910 1791031 -5.693 14.757 3.238 8 -5692.9 -1219.9 16917.3 1292681 -1378675 309470 1915083 -16.917 15.779 2.970 10 2720.2 3538.9 16917.3 1370462 -1161790 309470 1823100 -16.917 15.021 2.970 1I -2720.2 3371.3 16917.3 1401588 -1096440 301124 1804800 -13.291 14.871 3.057 16 -2720.I 2669.6 16917.3 1504866 -669073 241431 1664502 -13.291 13.715 3.057 13 -1999.I 2918.7 17245.4 1782654 907711 80863 2002082 -13.935 I6.496 3.041 14 -1999.1 2416.3 17245.4 1513808 1094210 20850 1867979 -2.416 15.391 3.317 15 -1999.1 1958.8 17245.4 1069756 1094210 30627 1530559 1.959 12.611 3.328

1) Loads are due to P + DW + SLTE + RCTE + TS P = Pressure DW = Dead Weight (Table B-1 of SIR-98-096)

SLTE = Surge Line Thermal Expansion (based on Mean of Pressurizer and

. Hot Leg Temperatures)(Table B-2)

RCTE = Reactor Coolant Loop Hot Leg Thermal Expansion (Table B-3 of  ;

SIR-98-096 Based on Hot Leg Temperature) j i TS = Thermal Stratification (Table B-4)

2) Stress due to bending is based on c' = M / nr2 t

3) See SIR-98-096 Appendix D Section D.6 for methods of determining loads based on the unit load cases provided in Appendix B of SIR-98-096. ,

4) Example for Mx at Node 2 Basic J Load Multiplier Load Contribution I

DW I -43,321 -43,321 SLTE (505-70)/(628.5-70) = 0.77887 174,450 135,874 i

-63,170 RCTE (400-70)/(604-70) = 0.617981 -39,038 TS 210/96.34 = 2.1798 659.590 1.437.761 Total 1,491,277 =

. l j

SIR-99-021, Rev. 0 3-1l gg,,gg,, y f,g,y,,gy pggggggggg, ggg,

Table 3-6 Intermediate Temperature Stratification Loads and Stresses (Case 6)

(AT= 295*F, Pressurizer Temp = 495*F, RCS Temp. = 200*F, Pressure = 635 psig)

Force, Ib Moments, in-lb fg*

• Nominal Stress, ksi Node Fx Fy ' Fz Mx My Mz A**

SRSS kips Moment pg 2 -3764.4 1161.5 10567.4 2047691 355391 573758 2156047 -1.161 17.765 1.275 3 -3764.4 659.2 10567.4 1873875 423146 5060u6 1986580 -10.567 16.368 1.050 4 -3764.4 -513.5 10567.4 1878657 671582 506006 2058255 -10.567 16.959 1.050 5 -3108.2 1015.9 10567.4 1864911 537327 492229 2002225 -3.108 16.497 1.228 7 -3108.2 -1623.7 10556.4 1864911 -760493 379589 2049471 -3.108 16.887 1.228 8 3108.2 -2126.I 11448.3 1831155 -910609 345836 2074111 -11.448 17.090 1.029 10 -1399.7 3874.9 11448.3 1897100 -794719 345836 2085706 -11.448 17.I85 1.029 11 -1399.7 3707.2 11448.3 1931254 -754467 336678 2100551 -9.215 17.308 1.082 16 -1399.6 3005.6 11448.3 2046022 -480343 270346 2118967 9.215 17.459 1.082 13 -985.6 2600.2 11828.6 2342937 536370 98719 2405575 -9.751 19.821 1.070 14 985.6 2097.8 11828.6 2166631 658281 59819 2265216 -2.098 18.664 1.252 15 -985.6 1640.3 11828.6 1862067 658281 34441 1975301 -1.640 16.226 1.263

1) Loads are due to P + DW + SLTE + RCTE + TS P = Pressure DW = Dead Weight (Table B-1 of SIR-98-096)

SLTE = Surge Line Thermal Expansion (based on Mean of Pressurizer and Hot Leg Temperatures) (Table B-2)

RCTE = Reactor Coolant Loop IIot Leg Thermal Expansion (Table B-3 of SIR-98-096 Based on Hot Leg Temperature)

TS = Thermal Stratification (Table B-4)

2) Stress due to bending is based on o = M / nr2 t

3) See SIR-98-096 Appendix D Section D.6 for methods of determining loads based on the unit load cases provided in Appendix B of SIR-98-096.

4) Example for Mx at Node 2 Basic Load Multiolier Load Contribution DW I -43,321 -43,321 SLTE (347.5-70)/(628.5-70) = 0.49687 174,450 86,678 RCTE (200-70)/(604-70) = 0.24345 -63,170 -15,378 TS 295/96.34 = 3.06207 659,590 2.019.712 Total 2,047,691 SIR-99-021, Rev. 0 3-12 gg,yggy,,y gaggy,ggypggggggggg, jng,

I l

Table 3-7 Normal Operating Condition Stresses without Stratification (AT = 0 F, Pressurizer Temp. = 653 F, Hot Leg Temp. = 604*F, Pressure = 2235 psig)

Force, Ib ^*I" Moments, in-lb Nominal Stress, ksi Node Fx Fy Fz Mx My Mz SRSS kips Moment

^*

pgf",

2 -10191.6 3573.9 19925.4 67959 286967 89613 308219 -3.574 2.540 4.499 3 -10191.6 3071.6 19925.4 230887 470408 -93836 532351 -19.925 4.386 4.108 4 10191.6 1898.8 19925.4 -66867 1143030 -93836 1148823 -19.925 9.466 4.108 5 8033.5 1396.5 19925.4 -37209 929001 -64179 931958 -8.034 7.679 4.393 7 8033.5 946.4 19528.3 -37209 -1483143 134339 1489679 8.034 12.274 4.393 8 -8033.5 444.0 20555.2 -24695 -1708519 146852 1714997 20.555 14.131 4.093 10 -3963.1 2104.9 20555.2 50702 -1398785 146852 1407386 -20.555 11.596 4.093 11 -3963.1 1937.3 20555.2 68907 -1313458 141970 1322904 -15.820 10.900 4.207 16 3963.0 1235.6 20555.2 123146 -771693 110618 789247 -15.820 6.503 4.207 13 -2970.2 2690.2 20695.7 261601 1218534 30591 1246673 -16.438 10.272 4.192 14 -2970.2 2187.9 20695.7 -72914 1451244 -44844 1453766 -2.188 11.978 4.532 15 -2970.2 1730.3 20695.7 -605826 1451244 -121326 1577293 -1.730 12.996 4.543

1) Loads are due to P + DW + SLTE + RCTE P = Pressure DW = Dead Weight (Table B-1 of SIR-98-096)

SLTE = Surge Line Thermal Expansion (based on Mean of Pressurizer and Hot Leg Temperatures) (Table B-2)

RCTE = Reactor Coolant Loop Hot Leg Thermal Expansion (Table B-3 of SIR-98-096 Based on Hot Leg Temperature)

2) Stress due to bending is based on o = M / nr2 t

3) See SIR-98-096 Appendix D Section D.6 for methods of determining loads based on the unit load cases provided in Appendix B of SIR-98-096.

4) Example for Mx at Node 2 Basic Load Multiplier Load Contribution DW l -43,321 -43,321 SLTE (628.5-70)/(628.5-70) = 1.0 174,450 174,450 RCTE (604-70)/(604-70) = 1.0 -63,170 -63.170 Total 67,959 SIR-99-021, Rev. 0 3-13 StructuralIntegrity Associates, Inc.

Table 3-8 Evaluation of Stress Ratios for Stratification Cases at All Locations Stresses NOC + AT = 49'F (Case 4) NOC + AT = 170*F (Case 3) 262 psig + AT= 340*F(Case 1)

P. P. P.+P3 P. P. P.+P. P. P. P.+P. -

Noz(2a) 2.820 2.902 5.721 2.833 7.239 10.072 0.328 13.224 13.552 NozSE(2b) 3.744 3.979 7.724 3.761 9.928 13.689 0.436 18.136 18.57i 2 (c) 4.504 4.422 8.925 4.523 11.031 15.554 0.524 20.151 20.675 3 4.104 4.094 8.197 4.I49 9.069 13.218 0.375 19.205 19.580 4 4.104 9.770 13.874 4.149 12.490 16.640 0.375 19.081 19.455 5 4.393 8.085 12.478 4.423 11.432 15.855 0.504 18.688 19.193 7 4.393 12.638 17.030 4.423 14.260 18.683 0.504 18.528 19.033 8 4.087 14.5 I I I8.598 4.I29 I5.663 19.791 0.354 18.348 I8.702 10 4.087 12.164 16.252 4.129 14.389 18.518 0.354 18.694 19.049 11 4.20l 11.528 15.729 4.229 I4.08I i8.310 0.385 18.917 I9.302

] I6 4.201 7.565 11.766 4.229 12.111 16.340 0.385 19.535 19.921 13 4.185 11.360 15.546 4.212 15.225 19.438 0.374 21.794 22.169 i

14 4.528 12.273 16.802 4.524 14.441 18.965 0.494 20.947 21.441 a 15(d) 4.539 12.229 16.768 4.535 11.993 16.529 0.504 19.254 19.759 -

SE/P(15c) 4.050 10.794 14.844 4.046 10.586 14.633 0.450 16.996 17.446 NozSE(15b) 3.410 9.833 13.243 3.407 9.644 13.050 0.378 15.482 15.859

Noz(15a) 3.175 9.083 12.259 3.172 8.908 12.081 0.352 14.301 14.653

Stress Ratios . Stratification Case / Normal Operating Stratified Case NOC + AT = 49 F NOC + AT = 170*F(Case 3) 262 psig + AT = 340*F (Case 1)

P. P. P.+ P. P. Pn P.+P. P. P3 P.+P. '

Noz(2a) 1.000 1.000 1.000 1.005 2.495 1.760 0.116 4.557 2.369 NozSE(2b) 1.000 1.000 1.000 1.005 2.495 1.772 0.116 4.557 2.405

, 2 (c) 1.000 1.000 1.000 1.004 2.495 1.743 0.116 4.557 2.316 i 3 1.000 1.000 1.000 1.011 2.215 1.612 0.091 4.691 2.389 4 1.000 1.000 1.000 1.011 1.278 1.199 0.091 1.953 1.402 5 1.000 1.000 1.000 1.007 1.414 1.271 0.115 2.312 1.538

, 7 1.000 1.000 1.000 1.007 1.128 1.097 0.115 1.466 1.118 8 1.000 1.000 1.000 1.010 1.079 1.064 0.087 1.264 1.006 10 1.000 1.000 1.000 1. b) 1.183 1.139 0.087 1.537 1.172 11 1.000 1.000 1.000 1.t 1.222 1.164 0.092 1.641 1.227 16 1.000 1.000 1.000 1.007 1.601 1.389 0.092 2.582 1.693 i 13 1.000 1.000 1.000 1.006 1.340 1.250 0.089 1.918 1.426 14 1.000 1.000 1.000 0.999 1.177 1.129 0.109 1.707 1.276 15(d) 1.000 1.000 1.000 0.999 0.981 0.986 0.111 1.574 1.178 SE/P(15c) 1.000 1.000 1.000 0.999 0.981 0.986 0.111 1.574 1.175 j NozSE(15b) 1.000 1.000 1.000 0.999 0.981 0.985 0.111 1.574 1.198 Noz(l5a) 1.000 1.000 1.000 0.999 0.981 0.985 0. I i 1 1.574 1.195

1) Pm = membrane stress / P3 = bending stress

2) For all locations with nominal pipe dimensions, stresses are as shown in Tsoles 3-4, 3-3, and 3-1. Other stresses are based on modified section properties at nozzle locations.

t

(

k SIR-99-021, Rev. 0 3-14 StructuralIntegrity Associates, Inc.

4

Table 3-9 10gpm Leakage Flaw Length and Area for Normal Operating Case 4-AT = 49 F (Pressurizer Temp. = 653*F, RCS Te.np. = 604*F, Pressure = 2235 psig)

Node Crack Length, in Area, in 2 Location

~

2a- A105 Hot Leg Nozzle 8.26 0.03787 2a SMAW Weld (Hot Leg Nozzle End) 8.33 '0.03796 2b SMAW Weld (Hot Leg SE End) 6.97 0.03388 2b CASS Safe-End at Hot Leg Nozzle 7.06 0.03402 2c SMAW Weld (Hot Leg SE/ Pipe End) 6.40 0.03208 2c CASS (Low Sy at Hot Leg SE/ Pipe) 6.48 0.03218 2c CASS (High Sy at Hot Leg SE/ Pipe) 6.49 0.03219 3 SMAW Weld 6.65 0.03243-3 CASS (Low Sy) 6.74 0.03256 i 3 CASS (High Sy) 6.74 0.03257 16 SMAW Weld 5.63 0.03091 16 CASS (Low Sy) 5.69 0.03098 16 CASS (High Sy) 5.68 0.03099 13 SMAW Weld (Node 13) 4.89 0.02976 13 CASS (Low Sy) 4.80 0.02961 13 CASS (High Sy) 4.87 0.02972 i

I SIR-99-021, Rev. 0 3-15

{ Structurs!IntegrityAssociates,Inc. l

Table 3-10 Material Properties for A105, Grade II Nozzle Value 70 F 334*F 483 F 605 F E (ksi) 28425 27063 26356 25680 Sy (ksi) 35.03 30.67 28.60 25.76 So (ksi) 60.0 60.0 60.0 60.0 Sr(ksi) 47.52 45.34 44.30 42.88 Ramberg-Osgood Parameter a 2.123 2.308 2.412 2.607 Ramberg-Osgood Parameter n 5.366 4.693 4.400 4.027 Jic (in-k/in') 1.05 1.05 1.05 Note 1 J-R Curve Parameter Ci (in-k/in#) 5.40 5.40 5.40 Note 1 J-R Curve Paramete.- N 0.344 0.344 0.344 Note 1 2

Jmu (in-k/in ) 3.5 3.5 3.5 Note 1 Note 1. Pr'operties not required since 605 F properties used only for the leakage calculations. ,

l i

I i

l l

4 l

l I

SIR-99-021, Rev, 0 ^ .3 16 g,,,,,,,,, ,,,,,,,,, ,gg gg,,,gg, ,gg,

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

1 Table 3-11 j Material Properties for SMAW Weld Metal.

l Value arameter 70 F 334 F 483 F 605 F 1

- E (ksi) 27341 26025 25344 24691 Sy (ksi)

{

60.14 52.80- 48.66 45.27 -1 So (ksi) 86.87 72.86 64.95- 58.48 ,

Sr (ksi) 73.51 62.83 56.81 51.88 Ramberg-Osgood Parameter cx 3.947 6.726 8.294 9.579  :

Ramberg-Osgood Parameter n 9.497 9.664 9.758 9.834 Jie (in-k/in') 0.288 0.288 0.288 Note 1 ,

J-R Curve Parameter Ci (in-k/in') 3.816 3.816 3.816 Note 1 J-R Curve Parameter N 0.643 0.643 0.643 Note 1 l Jm,u (in-k/in#) 2.345 2.345 2.345 Note 1 l Note 1. Properties not required since 605 F properties used only for the leakage calculations.

4 4

i 4

+ >

b S1R-99-021, Rev. 0 ' 3-17 StructuralIntegrity Associates, Inc.

P

4 i

Table 3-12

Material Properties of the A351 CF8M Cast Stainless Steel Spool '

Pieces of the Surge Line at 70 F -

Value i Node 2 Node 3 Node 13 Node 16 Parameter

Low High Low High Low High Low High  ;

Yield Yield Yield Yield Yield Yield Yield Yield '

E (ksi) 28544 28544 28544 28544 23544 28544 28544 28544 Sy = co(ksi) 45.80 48.20 45.80 48.20 42.10 47.00 45.80 47.00' 3

Sr(ksi) 68.25 69.70 68.25 69.70 64.70 68.10 68.75 68.10 Ramberg-Osgood 000 1 000 1 000 2.000 2.000 2.000 -

1000 Parameter a

1. 88 a er n 5.600 5.600 5.600 5.600 5.600' 5.600 5.6'0 0 5.600 2

Jic (in-k/in ) 0.65 0.65 0.65 0.65 0.65 0.65 0.65 0.65 J-R Curve Parameter Ci (in- 2.728 3.298 2.728 3.298 3.555 3.751 2.729 3.751 k/in') ,

0.3380 0.3 .o4 0.3380 0.3464 0.3497 0.3521 0.338 0.3521 P m N 2

J (in-k/in )(1) 2.00 2.40 2.00 2.40 2.58 2.72 2.00 2.72 (1) The value of Jmu determined for each spool at a crack extension (Aa) of 0.4 inch based on J

data provided in Reference 4.  !

l j

i i

l I

l 1

l l

1

- SIR-99-021; Rev. 0 3-18. gg,yggy,,,y,ggy,ygy,ggggggggg, ggg_

~

Table 3-13 Material Properties of the A351 CF8M Cast Stainless Steel Spool l Pieces of the Surge Line at 334"F '

Value Parameter Node 2 Node 3 Node 13 Node 16 Low High Low High Low High Low High Yield Yield Yield Yield Yield' Yield Yield Yield E (ksi) 27171 27171 27171 27171 27171 27171 27171 27171 S = c (ksi)'

y o 34.59 36.40 34.58 36.40 31.79 35.49 34.58 35.49 Sr (ksi) 61.34 62.49 61.34 62.49 58.29 61.06 61.34 61.06 Ramberg-Osgood 1.586 1.586 1.586 1.586 1.586 1.586 1.586 1.586 Parameter cr Ramberg-Osgood 6.151 6.151 6.151 6.151 6.151 6.151 6.151 6.151 Parameter n Jei 0.65 0.65 0.65 0.65 0.65 0.65 0.65 0.65 J-R Curve '

Parameter Ci (in- 2.938 3.418 2.938 3.418 3.625 3.790 2.938 3.790 2

k/in )

0.3220 0.3292 0.3220 0.3292 0.3319 0.3340 0.3220 0.3340 Pa me rN J,nu (in-k/in2 )(1) 2.19 2.53 2.19 2.53 2.67 2.79 2.19 2.79 (1) The value of Jmo determined for each spool at a crack extension (Aa) of 0.4 inch based on data provided in Reference 4.

a r

F t

S1R-99-021, Rev. 0 - 3-19 gg,,,,,,,, ,,,,,,,,, ,,g0g,,,,,, ,gg,

O Table 3-14 Material Properties of the A351 CF8M Cast Stainless Steel Spool Pieces of the Surge Line at 483*F Value Parameter Node 2 Node 3 Node 13 Node 16 Low High Low . High Low High Low High Yield Yield Yield Yield Yield Yield Yield Yield E (ksi) 26459 26459 26459. 26459 26459 26459 26459 26459 S = c (ksi) y o 30.77 3238 30.77 3238 28.28 31.58 30.77 31.58 Sr (ksi) 58.79 59.84- 58.79 59.84 55.92 58.48 58.79 58.48 8

13555 13555 1.3555 13555 13555 13555 13555 13555 ra er n Ramberg-Osgood 6.4643 6.4643 6.4643 6.4643 6.4643 6.4643 6.4643 6.4643 Parameter n Ju. 0.65 0.65 0.65 0.65 0.65 0.65 0.65 0.65 J-R Curve Parameter Ci (in- 3.071 3.494 3.071 3.494 3.674 3.815 3.071 3.815 2

k/in )

Pa e N 03118 03:82 03118 03182 03206 03225 03118 03225 2

Jmo (in-k/in )(1) 231 2.61 231 2.61 2.74 2.84 2.31 2.84 i

(1) The value of Jnm determined for each spool at a crack extension (Aa) of 0.4 inch based on data provided in Reference 4.

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SIR-99-021, Rev. 0 3 20 f StructuralIntegrityAssociates,Inc.

o Table 3-15 i Material Properties of the A351 CF8M Cast Stainless Steel Spool-Pieces of the Surge Line at 605 F Value Node 2 Node 3 Node 13 Node 16 -

Parameter Low . High Low . High Low High Low High Yield Yield Yield Yield Yield - Yield Yield Yield E (ksi) 25778 25778 2.5778 25778 25778 25778 25778 25778 Sy = a. (ksi) 28.62 30.12 28.62 30.12 26.30- 29.36 28.62 29.36 Sf 57.72 58.71 57.72 58.71 54.93 57.39 57.78 57.37

" ' *8 1.162 1.162 1.162 1.162 1.162 1.162 1.162 1.162 er a

1. 8 6.71 6.71 6.71 6.71 6.71 6.71 6.71 6.71 .

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SIR-99-021, Rev. 0 - 3 Structural Integrity Associates, Inc.

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Tcble 3-16 Material Properties of the A35i CfJM Cast Stainless Steel Low Yield Spool  !

Piece At Nodes 2 and 3 for 200 F and 400 F i l Parameter Value

, Temperature *F 200 400 E (ksi) 27860 26784 Sy = 0 (ksi) 39.39 32.67

' Sr(ksi) 65.04 59.74 l Ramberg-Osgood Parameter a 1.80 1.48 Ramberg-Osgood Parameter n 5.87 6.29 Ji c (in-k/in') 0.65 0.65

_J -R Curve Parameter Ci (in-kAn#) 2.818 2.997 J-R Curve. Parameter N 0.3311 0.3175 Jmu (in-k/in#) (1)- 2.08 2.24

(1) The value of Jmu determined for each spool at a crack extension (Aa) of 0.4 inch j based on data provided in Reference 4.

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SIR-99-021, Rev. 0 3-22 StrncluralIntegrity Associates, Inc.

Table 3-17 Critical Flaw Sizes for Case I with AAT = 340 F (Pressurizer Temperature = 410 F, RCS Temperature = 70"F, Pressure = 262 psig)

Locatien Stress, ksi Half-Critical Flaw Size, Inches ,

Node Material S, Tension Bending Total a, n. a, 2a SA-105 - 0.328 13.224 13.552 7.0909 8.7610 8.7206 2a SMAW -

0.328 13.224 13.552 8.3845 9.3000 9.2778 2b SMAW - 0.436 18.136 18.572 6.6525 8.0287 7.9964 2b CASS LOW 0.436 18.136 18.572 5.4212 6.9817 6.9451 2c CASS LOW 0.524 20.151 20.675 4.9734 6.4442 6.4069 2c SMAW - 0.524 20.151 20.675 6.2236 7.6642 7.6277 2c CASS HIGH 0.524 20.151 20.675 5.2830 6.8350 6.7957 3 CASS HIGH 0.375 19.205 19.580 5.5212 7.1284 7.0976 3 CASS LOW 0.375 19.205 19.580 5.2058 6.7304 6.7012 13 CASS IIIGH 0.374 21.794 22.168 5.0501 6.5644 6.5389 13 CASS LOW 0.374 21.794 22.168 4.7235 6.1956 6.1708 16 CASS HIGH 0.385 19.535 19.920 5.5221 7.1332 7.1021 16 CASS LOW 0.385 19.535 19.920 .5.1326 6.6400 6.6109 1

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Table 3-18 Critical Flaw Sizes for Case 2 with A AT = 242*F '

i (Pressurizer Temperature = 576*F, RCS Temperature 334*F, Pressure = 1270 psig)

[

Location Stress, ksi IIalf-Critical Flaw Size, inches Node Material S, Tension Bending Total a, an a,  ;

2a S A-105 -

1.604 9.796 11.400 7.4780 9.1887 8.9480 2a SMAW -

1.604 9.796 11.400 8.4693 93000 9.1831 2b SMAW - 2.130 13.434 15.564 6.7995 8.0887- 7.9123 2b CASS LOW 2.130 13.434 15.564 5.6640 7.2144 7.0022 2c CASS LOW 2.562 14.926 17.488 5.1620 6.6686 6.4479 ,

2c SMAW - 2.562 14.926 17.488 63115 7.7066 7.5022 2c CASS HIGH 2.562 I4.926 17.488 5.4359 6.9956 6.7671

3 CASS HIGH 2.263 13.!S I 15.414 6.0064 7.6353 7.3962 3 CASS LOW 2.263 13.151 15.414 5.7287 7.3271 7.0924 13 CASS HIGH 2.303 17.715 20.018 4.8492 6.3350 6.1641 13 CASS LOW 2.303 17.715 20.018 4.5234 5.9571 5.7922 16 CASS HIGH 2.318 15.108 17.426 5.4800 7.0485 6.8399 ,

16 CidS LOW 2.318 15.108 17.426 5.1776 6.6863 6.4856 i

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I-Table 3-19 Critical Flaw Sizes for Case 3 A AT = 170 F

(Pressurizer Temperature = 653*F, RCS Temperature 483"F, Pressure = 2235 psig) l i Location Stress, ksi Half-Critical Flaw Size, inches Node Material S, Tension Bending Total a. a. a, 2a SA-105 -

2.833 7.239 10.072 7.8253 - 9.3000 8.8852 2a SMAW -

2.833 7.239 10.072 8.624 9.3000 9.1099 1 2b SMAW - 3.761 9.928 13.689 6.9734 8.2284 7.8836 .

2b CASS LOW 3.761 9.928 13.689 6.0127 7.5614 7.1359 2c CASS LOW 4.523 11.031 15.554 5.4606 7.0021 6.5538

^

2c SMAW - 4.523 11.031  !!M4 6.4433 7.8170 7.4175 j 2c CASS HIGH 4.523 11.031 15.554 5.7151 7.2875 6.8303 3 CASS HIGH 4.149 9.069 13.218 6.4567 8.0801 7.5705 3 CASS LOW 4.149 9.069 13.218 6.1999 7.8458 7.3292 13 CASS HIGH 4.212 15.225 19.437 4.6967 6.1668 5.8482 l 13 CASS LOW 4.212 15.225 19.437 4.3359 5.7859 5.4717 i

16 CASS HIGH 4.229 12.111 16.34 5.4968 7.0469 6.6457 16 CASS LOW 4.229 12.111 16.34 5.2366 6.7390 6.3502 4

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Table 3-20 <

. Comparison of Critical and 10 gpm Flaws fo'r .I Weld Locations at Nodes 2,3,13, and 16 - 1 1

One-Half Critical Flaw Size (inches) 10 gpm Critical Node Leakage Flaw to l Material No- Case 1 (1) Case 2 (2) Flaw Size, Leakage l Case 3 (3)

(inches)(4) Size Ratio l 2a A;05 C 2 II 8.72 8.95 8.88 8.26 2.11 2a SMAW 9.2d 9.18 9.11 8.33 2,19 2h SMAW 8.00 7.91 7.88 6.97 2.26 2b Cast Stainless Low Yield 6.95 7.00 7.14 7.06 1.97

~

2c Cast Stainless Low Yield 6.41 6.<. 5 6.55 6.48 1.98 2c SMAW 7.63 7 50 7.42 6.40 2.32' 2c Cast Stainless High Yield CE 6.77 6.83 6.49 2.09 i 3 (5) Cast Stainless High Yicid 7.10 7.40 7.57 6.74 2.11 3 Cast Stainless Low Yield 6.70 7.09 7.33 6.74 1,99 13 (5) Cast Stainless High Yield 6.54 6.16 5.85 4.87 2.40 13 Cast Stainless Low Yield 6.17 5.79 5.47 4.80 2.28 16 (5) Cast Stainless Low Yield 6.61 6.49 6.35 5.67 2.24 16 Cast Stainless High Yield 7.10 6.84 6.65 5.68 2.34 Notes: 1. Case 1 is startup with AT = 340 F, pressurizer at 410 F/262 psig and RCS at 70 F.

2. Case 2 is cooldown with AT = 242 F, pressurizer at 576 F/1270 psig and RCS at 334 F.

3. Case 3 is cooldown at full pressure with AT = 170 F, pressurizer at 653 F/2235 psig and RCS at 483 F.

4. From Table 3-9, total flaw length.

5. SMAW not evaluated at Locations 3,13 and 16 since cast stainless steel is always more limiting.

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I Table 3-21 i

Critical Flaw Sizes Based on 8 Factor on Normal Plus SSE Loads (All Locations are A351 CF8M Cast Stainless Steel)

Location / Load Case Stress, ksi Critical Flaw Size, inches Node Load Case S, Tension liending Total a, a. 2a, l 2b i LOW 0.436 18.136 I8.572 3.9394 5.I882 10.318 2c  ! LOW 0.524 20.151 20.675 3.3269 4.6478 9.229 2b 2 LOW 2.130 13.434 15.5M 4.0991 5.4670 10.560 2c 2 LOW 2.562 14.926 17.488 3.4478 4.8879 9.354 2b 3 LOW 3.761 9.928 13.689 4.4619 5.8488 10.936 2c 3 LOW 4.523 11.031 15.554 3.7989 5.2322 l 9.631 5

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SIR-99-02 l, Rev. 0 3-27 gg,,ggy,,, y,,,,,,gy pgggg,gggg, pgg,

l Table 3-22 Critical Flaw Size Comparison for Cas. ., with AT = 210 F '

(Pressurizer Temperature = 610 F, RCS Temperature 400 F, Pressure = 1645 psig)

Stress, ksi Half Critical Flaw Size, inches 10 gpm Critical Node Leakage . Flaw to Tension Bending Total a, a6 a, Flaw Size, Leakage inches Ratio 2b (1) 2.763 11.867 14.630 5.8270 7.3801 7.0868 7.06 2.01 2c (1) 3.323 13.I85 16.508 5.3044 6.8270 6.5205 6.48 2.01 3 (1) 2.99i 11.290 14.281 5.9608 7.5718 7.2344 6.74 2.15 Note: 1. All have material properties for low yield strength CASS material.

Table 3 23 Critical Flaw Size Comparison for Case 6 with AT = 295 F j (Pressurizer Temperature = 495 F, RCS Temperature 200 F, Pressure = 635 psig)

Stress, ksi Half Critical Flaw Size, inches 10 gym Critical Node Leakage Flaw to Tension Bending Total ai a6 a, Flaw Size, Leakage inches Ratio 2b (1) 1.059 15.988 17.047 5.5087 7.0648 6.9681 7.06 1.97 2c (1) 1.275 17.765 19.040 5.0390 6.5307 6.4308 6.48 L99 3 (1) 1.050 16.368 17.418 5.4308 7.0021 6.9074 6.74 2.05 Note: 1. Both have material properties for low yield strength CASS safe-end material.

r SIR-99-021, Rev. 0 3-28 StructuralIntegrity Associates, Inc.

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(505-02) lC4619-2] '@-" 7 (505-062)

(505-03) lC46204] .j l C-4621 il 3

(505-13)

IC46191l (504-14) IC4619 31 Hoe

a,g, o Leg (404-03) 16 (505-04 1) (506-04) lC-3223-1Rl [C-46181)

(C4620 2] ,

W (505-09) (505-06) l lC-4619-4] . 1C-4619-51 1 Sv g O Node Numbers l

() Spool Piece Number (505-15-1) l c-46201l C Materialidentifier f

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l Figure 3-1. Surge Line Piping Materials and Node Identification 1

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SIR-99-021, Rev.~ 0 3-29

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- _._...___w---___ ___. - _----_.- -_ ---__.

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~ HOT LEG NOZZLE OD = 13.5"

, OD = 12.75"

', C-4618-1 M. ,

SA-105 Cast Stainless 2a 2b ID = 10.125" / N t = 1.6875"J L =t 1,3125" t = 1.148" 98206ri Figure 3-2. Locations for Evaluation at Hot Leg Nozzle f

i SIR-99-021, Rev. 0 3-30

StructuralIntegrity Associates, Inc.

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700 Case 3 650 "

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600-Case 2 /

a 550- '

k l500 **

T 450 #

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E o., 400

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.i 300 50 100 150 200 250 300 350 400 450 500 '550' Hot Leg Temperature, F -

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4.0 CONCLUSION

S An evaluation has been conducted to determine the allowable pressurizer temperature as a function of hot leg temperature so that LBB margins can be maintained. The evaluation covered the complete range of operating temperatures. The results are shown in figure 3-3.

This evaluation has demonstrated that for the initial heatup transient with AT = 340 F at 262 psig, the margin between the critical flaw size and the 10 gpm leakage flaw is mainta'med at essentially a factor of 2.0 for the limiting surge line location. This condition conservatively bounds the most severe case of stratification that is expected at the plant.

At the beginning of reactor cooldown, the maximum AT that can be tolerated without violating LBB margins on flaw size is 170 F assuming that there is no pressurizer cooldown and full operating pressure is maintained. However, cooldown is associated with decrease in pressure and when a more realistic cooldown case (based on actual recorded measurements) was used, it was shown that the required margin could be shown with a AT = 242*F with the reactor at 1270 psig. Several other cases at intemediate conditions were evaluated that demonstrated additional AT margin is gained as the pressurizer pressure and temperature decrease during the continued cooldown. These evaluations are equally applicable to reactor conditions during heatup.

It is noted that the margins demonstrated in this evaluation were slightly less than the NUREG-1061 Volume 3 factor of two between the critical flaw size and the leakage flaw size (1.97 versus 2.00) at the limiting locations. The NUREG-1061 margin is based on the combination of normal operating loads plus the SSE seismic load, with the SSE load being a primary, non-displacement limited loading. For the current evaluation, the only primary loading conditions are dead weight and pressure, loadings that are a small portion of the total load. The most significant loadings are due to piping thermal expansion effects (surge line thermal expansion, hot leg nozzle movement and stratification); all are displacement limited loadings. A5iviD0mion XI flaw evaluation procedures do not require that a margin be applied to secondary loadings in evaluation of actual flaws, whereas a factor of safety must be applied to primary loadings. Thus, it is reasonable to accept the slightly reduced margins demonstrated in this report.

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5.0 . REFERENCES 4

1. SIR-98-096, " Pressurizer Surge Line Leak Before Break Evaluation - Millstone Nuclear Power Station, Unit 2", Rev. 0, October 1998.

l 2. CE00 Report CEN-387-P, key 1-P-A," Pressurizer Surge Line Flow Stratification Evaluation," May 1994.

3. EPRI NP-4768," Toughness of Austenitic Stainless Steel Pipe Welds," October 1986.

l 4. NUREG/CR-4513, Rev.1," Estimation of Fracture Toughness of Cast Stainless Steels i During Thermal Aging in LWR Systems," August 1994. ,

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- Docket No. 50-336 -

817682 i

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Attachment 3 Millstone Nuclear Power Station, Unit No. 2 ,

Response to Request For Additional Information Concerning Leak Before Break Evaluation of the Pressurizer Surge Piping Commitments  !

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P February 1999 t

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i U.S. Nucl::Ir Regulitory Commission o B17682\ Attachment 3\Page 1 l Attachment 3 Regulatory Commitment Enclosure List of Regulatory Commitments  !

The following table identifies those actions committed to by NNECO in this document. Any other actions discussed in the submittal represent intended or planned actions by NNECO.

They are described to the NRC for the NRC's information and are not regulatory commitments. The Manager - Regulatory Affairs should be contacted if any questions regarding this document or any associated regulatory commitments arise.

REGULATORY COMMITMENT. COMMITTED DATE OR OUTAGE B17682.01: In order to minimize / eliminate those Within 30 days after receipt of plant conditions which could result in ATs in the NRC SER for Pressurizer excess of those provided in Figure 1 of this letter, Surge Line LBB methodology.

NNECO will incorporate the information from this figure into the appropriate plant procedures.

l l