ML20005E826
| ML20005E826 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 12/31/1989 |
| From: | Bond C, Chang K, Raju Patel WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| To: | |
| Shared Package | |
| ML19310C599 | List: |
| References | |
| WCAP-12219-S01, WCAP-12219-S1, NUDOCS 9001110128 | |
| Download: ML20005E826 (31) | |
Text
{{#Wiki_filter:a h, WESTINGHOUSE CLASS 3 ij ' . t- l
'WCAP.12219 1 . c4 Supplement 1 *4 ys Le -
I l SUPPLEMENTARY. ANALYSIS TO ADDRESS J
. THERMAL STRATIFICATION FOR V0GTLE UNIT l' PRESSURIZER SURGE LINE v December, 1989 a.
'B. J. Coslow B. R. Mutyafa
- E. L. Cranford L. M. Valasek B. F. Maurer F. J. Witt T. H. Liu Verified by: // _.
Verified by: UM - / K. C. Chahg C. 5. Bond.' ' Approved by: 1 b* Approved by: M/IMW
' 5. 5.'Palusamy, Manager R. 57 Patel, Manager Systems Structural Analysis Structural Materials and Development Engineering Work Performed Under Shop Orders GDDP-2006A,B C,0 I
e. [ WESTINGHOUSE ELECTRIC CORPORATION Nuclear and Advanced Technology Division > P.O. Box 2728
- Pittsburgh, Pennsylvania 15230-2728 ,
~~ ~'
9001110128 900104 PDR ADOCK 05000424 o PDC
i FOREWORD Surge line stratification of Vogtle Unit 2 was addressed in WCAP-12218 wherein it was shown that adequate margins in ASME Code compliance for the design life exist under the influence of thermal stratification. The original support system of two rigid supports was modified, replacing one rigid with a snubber and spring hanger to qualify the Unit 2 surge line. The Unit 1 surge line will be modified (similar to Unit 2) during the 1990 refueling outage.
However, the Unit 1 surge line will have the original support system (with two rigid supports) through the 1990 refueling outage. This supplement summarizes the additional plant specific evaluation to demonstrate Code compliance for the Vogtle Unit 1 surge line. This evaluation is for the design life of the plant and considers the original and modified (similar to Unit 2) support systems. Q-e e b
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yc TABLE OF CONTENTS
- o; Section Title Page 1.0 DESIGN TRANSIENTS 1-1 2.0 STRESS ANALYSIS 2-1
< 3.0 ASME SECTION III FATIGUE USAGE 3-1
^
FACTOR EVALUATION-4.0 FATIGUE CRACK GROWTH 4-1 < 4.1 Introduction 4-1
, 4.2- Analyses 4-1 !
. 4.3 - Conclusion 4-2 I
~l ;
.y . 5.0 REASSESSMENT OF LEAK-BEFORE BREAK 5-1
. 5.1 Introduction 5-1
*- -5.2 Material Properties 5-1 5.3 lThe Surge Line Configurations 2 5.4 Discussion 5-2
. 5. 5 Conclusions 5-3 j 5.6 References 5-3 i
6.0 - CONCLUSIONS 6-1 ERRATA E-1 0 b V
1 i e i
!*2 LIST OF1 TABLES o
Table Title 'Page S1-1 Heatup/Cooldown Transients for Past Operation of Unit 1 1-4 S1-2 (- 1 8 'C Transients for Past Operation of Unit i 1-5 ' 1 Worst Case Fatigue Crack Growth Results for an Initial Crack 10% of the Wall 4-3 55-1 Room Temperature Machanical Properties of Surge Line Materials and Welds of_ the Vogtle Unit 1 Plant 5-4 S5-2 Tensile Properties for Vogtle Unit 1 and Vogtle Unit 2' at Room Temperature 5-5 e b o.
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iv , m:i : i Li LIST.0F FIGURES ',
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P ;, Figure-~ Title Page [ l JSI Hot-Cold Interfece Location [ Ja.c.e 1-6 S1 'Voitle Unit 2 H.,nitoring Data - Safe End' 1-7 3~ Vogtle Unit 2 Monitoring Data - Near H006 1-8 SI-44 Vogtle Unit 2 Monitoring Data - Near TE450 1-9 SI Vogtle Unit 2 Monitoring Data - Near H001 1-10 S5-1 -Comparison of Vogtle Unit 1 and Vogtle Unit 2 Surge Line t Configurations 5-6 - Of 4
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SECTION 1.0
, DESIGN TRANSIENTS !
This section discusses the methods used to update design transients for evaluation of thermal stratification on Vogtle Unit 1 Surge Line.
'Section 1.0 of WCAP-12218 presents the methods used to update design
. transient for evaluation of thermal stratification on Vogtle Unit 2 Surge Line. Except for operating history, the two units are identical in regard to the primary factors which affect thermal stratification transients (operating methodsandpipinglayout). In the development of the Unit 2 transients. .
monitoring data and historical records from several plants were utilized. This included monitoring data from Vogtle Unit 2. Since Unit 2 had not experienced significant operating history at the time the evaluation was-
+ performed,.a review of the Unit 2 operating' procedures combined with the review of historical records from other plants was used, t .
For Unit 1, significant operating history has occurred since hot' functional testing in mid 1986. This operating history was reviewed for its effect on
~~
- the design transients previously developed for Unit 2. Operating logs were reviewed to determine maximum estimated temperature differences between the pressurizer and the Reactor Coolant Loop (RCL) hot leg during past heatups and cooldowns on Unit 1. Based on this information, a set of updated design i
transients was developed for Unit I to represent the effect of past-heatups and cooldowns. L Based on the review of operating logs, it was determined that a system delta T l (difference in temperature between the pressurizer and the hot leg) of [. Ja,c.e actually did occur during one of the past heatups. During one of the past cooldowns, a system delta T of [ Ja.c.e also occurred according to the logs. Since there was no monitoring instrumentation M installed on the Unit I surge line during these past operations, it is not known for certain the extent of the stratification in the pipe during these
~
and other times. For conservatism, however, it is assumed that stratification
- i. did occur in the pipe at these times and at all other times of maximum system delta T during past heatups and cooldowns. Using this data and methods 1-1
[F ny s p' similar to those discussed 'in WCAP-12218,~ the set of heatup and cooldown
- transients shown,in table S1-1 was developed to represent'past heatup - ,
[*L: s o .cooldown operation at Unit 1. [ I
. a t
ja,c.e g In addition to developing past hestup and cooldown transients for Unit 1, a distinction-was made in the axial stratification profile { , Ja,c,e Monitoring data taken at Unit 2,-which has the same layout and slope as. Unit 1, ' confirms this. The data also indicates that the maximum pipe delta T-(difference between pipe top and bottom temperatures) ,
. values occur during ( Ja,c.e t
1
. An example of this phenomena is shown in figures S1-2 thru S1-5. 'These figures present monitoring data obtained on the Vogtle Unit 2 surge line L during plant cooldown on 10/22/88. During this cooldown, instrumentation was L located as shown in figure 1-7 of WCAP 12218 except that RTD#3 was located on the loop side of the wall and very near support H001.
i l-L At approximately 20:25 the RC pump, in the loop with the surge line, was tripped. [ L l ?-* 3a,c.e 1-2
1 o i e. At approximately 20:41 operators began collapsing the pressurizer- steam bubble > [. , i
'.I t i
)a,ce, For future Toperation at Unit 1, the transients developed for Unit 2.and presented in tables 1-3 and 1-4 and axial profile shown in figure 1-18 of
; WCAP-12218 are considered, Since the heatup/cooldown transients of table 1-3
-were' based on ( Ja,c,e cycles, . the number of cycles'in this table are reduced by ( ~)a,c.e to account for the transients considered in the past per tables S1-1 and S1-2. -
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, 1-3
- r TABLE S1-1
, HEATUP/000LDOWN TRANSIENTS FOR PAST OPERATION OF UNIT 1 Heatup Cooldown <
3388333333333388333583888888888SSS 3885883333333333333333333333335SSS Transient Cycles System Delta T Transient Cycles System Delta T , 88WB333383333333 58888833333338 8333333333333338 338388R8333333
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. ,. 1 TABLE S1-2 .)
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[.. )"'C TRANSIENTS FOR PAST OPERATION OF UNIT 1 Heatup Cooldown
.................................. .................................. -i Transient Cycles System Delta T' Transient Cycles System Delta T
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l l Figure SI-4. V0GTLE UNIT 2 MONITORING DATA - NEAR TE450 1-9
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1 e L__ SECTION 2.0 L*, STRESS ANALYSIS L, The pressurizer surge piping layout of Unit 1 is a reflection of that for Unit 2. The original support configuration of the Unit I consists of two ' rigid supports (H002 & H006), unlike Unit 2 which consists of only one rigid ' (H002). It should be noted that the Unit I surge line will be modified during 1990 refueling outage to be the same as that of Unit 2 surge line (H006 replaced with snubber and spring hanger). The Unit 1 plant specific structural analysis was performed to determine the effects of thermal stratification for the original support system and modified support system L (Unit 2 results) based on the transients and axial temperature profiles developed in section 1.0. Though the maximum thermal stratification of (
-. Ja,c.e 33 described in secW91.0, figure S1-1, was used. Therefore, it is concluded
- that the Unit ; maximum stress intensity range is less than the results-
.- reported in WCAP-12218 for the Unit 2 surge line.
Pipe movements at supports and pipe whip restraints and nozzle qualification have been reconciled to incorporate the stratification effects for the original and modified (similar to Unit 2) support systems. The resulting load on remaining rigid support H002 is acceptable. The local-stresses due to the non-linear portion of the radial temperature distribution in the pipe cross-section were recalculated for the transients and stratification delta T developed in section 1.0. [ ja,c.e
. The methodology and results were conservatively calculated to address striping stresses for Unit 2 and hence used for the Unit 1 surge line.
Therefore, the Unit 2 surge line results and conclusions provided in section 2.0 of WCAP-12218 are also applicable to the Vogtle Unit 1 surge line. 2-1
i 4: SECTION 3.0 ASME SECTION !!! FATIGUE USAGE FACTOR EVALVATION Fatigue usage factors for the Vogtle Unit 1 surge line were calculated based on the requirements of the ASME B & PV Code, Section III. With thermal i transients redefined to account for thermal stratification as described in ) section'1.0 and the stresses in the piping components established in section 2.0, the new fatigue usage factors were calculated. ' Fatigue evaluation was performed to demonstrate Code compliance for the Unit I surge i line for the design life of the plant considering original and modified (similartoUnit2)supportsystems. L A detailed analysis was performed for the two worst locations, [ ,
. Ja,c.e This analysis showed no increase
, . . in cumulative usage factors compared to Unit' 2 results. Therefore,-it can l be concluded that cumulative usage factors for all components remain within
, the Code allowables of 1.0.
Therefore, the Unit 2 surge line-results and conclusions provided in L.- section 3.0 of WCAP-12218 are also applicable to the Vogtle Unit 1 surge line. l l L l: l l l- . l l' 3-1
[ ,4 SECTION 4.0 ;
.. FATIGUE CRACK GROWTH
- 4.1 Introduction Fatigue crack growth results were presented in WCAP-12218 for forty year service of the pressurizer surge line of Vogtle Unit 2 including consideration of thermal stratification. The maximum wall penetration was only slightly over half of the NRC recommended allowable. In this section, a similar evaluation is presented for Vogtle Unit-1 at the most critical locations. For
- Unit 1, the first three years of the calculation are for the original two rigid support configurations with the remaining thirty-seven years.for the modified one rigid support configuration (i.e., the Vogtle Unit 2 configuration). For conservatism the one-support configuration was actually evaivated for forty year service making a to'tal service of forty-three years.
4.2 Analyses
~
. The same approach was used for the Vogtle Unit 1 fatigue crack growth analyses as was for the Vogtle Unit 2 analyses as described in WCAP-12218 which provides specific details. Sections 1.0 and 2.0 of this supplement. provide the design transients and the stresses for the original support configuration, respectively. Section 2.0 of WCAP-12218 provided these stresses for the modified support configuration.
- The fatigue crack growth was determined at the critical locations (see table 4-1 of WCAP-12218) for the same flaw sizes examined (a six-to-one aspect ratio flaw having a depth of 0.141 in, for the 14 in. pipe and 0.159 in, for the 16 in, pipe). The results are given in table S4-1.
In table S4-1, it is seen that the full service life track growth for Vogtle Unit 1 only slightly exceeds that of Vogtle Unit 2 (table 4-1 of WCAP-11218; please note the ERRATA of this supplement for location 5 in that table). The final crack depth is much less than 60% of the wall thickness which is the recommended allowable of the NRC. 4-1
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; Anticipated fatigue crack growth is reasonably small for the Vogtle Unit l' l
;* pressurizer. surge line for full service life including the presence lof thermal -
. stratification,:_ Leakage caused-by fatigue crack-growth-would not be expected, i i
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. TABLE S4-l' o
WORST CASE FATIGUE CRACK GROWTH RESULTS FOR AN INITIAL CRACK 10% OF THE WALL
'4
% of Wall Initial Final Flaw- of Final Location- Position- Size-(in.) Size (in.) Flaw Size
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4-3
y. o_ SECTION 5.0 LEAK-BEFORE-BREAK EVALUATION
. -g ,
. 5.1 Introduction Leak-before-break including the consideration of thermal stratification was successfully demonstrated for Vogtle Unit 2 in WCAP-12218. The surge line
' configuration and. loadings for'Vogtle Unit 1 (with the modified support configuration)_are identical to those of Vogtle Unit 2. The leak-before-break demonstration for Vogtle Unit 2 would apply equally well to Vogtle Unit 1 if the material, material properties and welds were identical. In this section a leak-before-break demonstration is presented for the Vogtle Unit 1 pressurizer surge line strongly referenced to the similar demonstration for Vogtle Unit 2.
5.2 Material Properties. E [ The room temperature mechanical properties of the Vogtle Unit 1 surge line materials were obtained from the Certified Materials Test Report and are given _in table S5-1. A similar table for Vogtle Unit 2 is given in table 5-3 of WCAP-12218. It is observed that the materials of corresponding product forms are the same 1 and all three 16 in, pipe heats in Vogtle Unit I have identical heats in Vogtle Unit 2. The 14 in, segments differ however. The reducers have identical heats. Most of the weld wires are common to both units. The nozzles are from the same heat. Comparisons of minimum and average room temperature tensile properties for Vogtle Unit 1 and Vogtle Unit 2 pipes are given in table SS-2. The significance of these results is discussed in Section 5.4. O 5-1
i i 5.3 The Surge Line Configurations i Sketches of the surge line configurations for Vogtle Unit 1 and Vogtle Unit 2 are given in figure 55 .1. The welds are not exactly at identical locations t nor do the weld types exactly correspond. However, GTAW welds are superior to SMAW welds per !WB 3640 (reference 5-1). Thus Vogtle Unit 1 welds are seen to be a+ least as good as those for Vogtle Unit 2 for corresponding locations. < Nost importantly, the weld types essentially agree at the critical locations noted by 2060 and 2720 in figure $5-1. 5.4 Discussion Figure 55-1 shows that stability evaluations for both units at the critical locations, based on IWB 3640 (reference 5-1), would be performed taking the same penalties. - l . The results of table S5-2 are very revealing, first the minimum yield stresses are the same. Thus, higher temperature minimum yield stresses would be'the same for both units since the method of determining ine higher ;
- temperature properties is based on room temperature valuen (see table 5-4 of i WCAP-12218). Noting no first paragraph of this section, the stability evaluations at the critical locations for a given flaw siza would be identical for Vogtle Unit 1 and Vogtle Unit 2. Also the room temperature average yield
- l. stress for Vogtle Unit 1 is less than that of Vogtle Unit 2. Thus for Vogtle 1
Unit I the higher temperature yield stresses are lower than the corresponding ones for Vogtle Unit 2. The avtrage tensile properties are used in the leak rate calculation. For a given leak rate (10 gpm is of interest here) lower 1-tensile properties produce smaller leakage size flaws. Thus the leakage size i flaws of Vogtle Unit I are smaller than those of Vogtle Unit 2 at the same l locations. 1 In summary, the leakage size flaws for Vogtle Unit 2 (see table 5-10 of
. WCAP-12218) are larger that those for Vogtle Unit 1 and the critical flew , sizes are the same. Thus the margins for Vogtle Unit 1 exceed those given in table 5-10 of WCAP-12218 for Vogtle Unit 2.
5-2
5.5 Conclusions J Since leak before-break has been successfully demonstrated for Vogtle Unit 2 that demonstration applies equally well to Vogtle Unit 1, and, in fact, the Vogtle Unit 2 analysis is conservative for Vogtle Unit 1 as demonstrated above. 5.6 References 5.1 ASME Code Section XI, Winter 1985 Addendum, Article IWB-3640. 4 4
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TABLE 55-1 ROON TEMPERATURE MECHANICAL PROPERTIES OF SURGE LINE MATERIALS AND WELDS OF THE V0GTLE UNIT 1 PLANT 2% Offset Ultimate Flow Yield Stress Strength Stress % Elongation % Reduction Product Heat in Area Form Number Material (psi) (psi) (psi) Per Inch 42,200 82,700 62,450 53.8 72.5 16 in. pipe L 4016 SA376-TP316 42,200 81,400 61,800 52.5 63.5 16 in. pipe L 4016 SA376-TP316 42,900 79,900 61,400 56.7 70.4 16 in. pipe L 4016 SA376-TF316 42,400 86,500 64,450 53.9 73.1 14 in. pipe J 6%9 SA376-TP316 N/A 92,500 N/A 41.0 N/A Weld 7J5859A SFA5.9-ER308 N/A 92,900 N/A 36.0 N/A Weld 5006154A AS.4-E308 N/A 92,400 N/A 42.0 N/A Weld 06391 SFA5.4-E308 67,500 91,500 79,500 41.0 54.0 Weld SC21721 A5.4-E308 N/A N/A N/A N/A N/A Weld 9F-7676E SFA5.9-ER308 { 36,940 82,630 57,790 62.5 76.3 Reducer 624107 SA403-WP304 (16 in.x14 in.) 43,960 94,110 69,040 50 74.1 Nozzle 636443 SA182-F316N ASME Code Minimum Requirement Pipe SA376 TP316 30,000 75,000 Reducer SA403 WP304 30,000 75,000 Weld E308 - 80,000 Nozzle SA182 F316N 35,000 80,000 N/A: Not Available .
i [ ;
- o. ;
. 4 P d TABLE S5 2 ; TENSF e, PROPERTIES FOR V0GTLE UNIT 1 AND V0 Git! UNIT 2 PIPES AT ROOM TEMPERATURE Yield Stress (psi) Ultimate Strength (psi) Average Minimum . Average Minimum Vogtle Unit 1 42400 42200 82600 79900
- Vogtle Unit 2 .43400 42200 82900 79900 in 4
-4 0
h 5-5
i' Patssuntzta Vogtle Unit 1 mt t
,g 99
& s' 8 s
e I e e A: Critical Locatient e : GTAW Weld aihe weld is GTAW but a e : s* W W8Id
. SmW weld repair was made. o: sAW Weld Patssuntztn Vogtle Unit 2 Het l'8 27
&s 2060 *A l
o b
- Figure S5-1. Comparison of Vogtle Unit 1 and Vogtie Unit 2 Surge Line Configurations 4 3 5-6
SECTION 6.0 CONCLUSIONS t-Based on Unit I historical data Unit 2 analysis results (WCAP-12218) and the I additional analysis results of the Unit I surge line presented in this supplement, the following conclusions are reached: (a) Based on Unit I historical data and monitoring data from Unit 2, the thermal transients for the Unit 1 surge ~line have been updated to incorporate the effects of thermal stratification. (b) The global structural and local stresses in the Unit i surge line meet ASME Code allowables with the original support system (2 rigids - H002 and H006) and with the modified (similar to Unit 2) support system (H006 replaced by snubber and spring hanger). The
, maximum stress intensity range and cumulative usage factor provided in WCAP-12218 for Unit 2 are also applicable to the Vogtle Unit 1
. surge line.
(c) Anticipated fatigue crack growth is reasonably small for the Vogtle Unit 1 pressurizer surge line for full service life including the l presence of thermal stratification. Leakage caused by fatigue crack growth would not be expected. (d) Since leak-before-break has been successfully demonstrated for Vogtle Unit 2, that demonstration applies equally well to Vogtle
' Unit 1, and, in fact, the Vogtle Unit 2 analysis is conservative for Vogtle Unit 1.
l In summary, based on Unit I historical data, Unit 2 results (WCAP-12218) and on the current understanding of the thermal stratification phenomenon, it is l
. concluded that thermal stratification does not compromise the structural
- l. integrity of the pressurizer surge line of the Vogtle Unit 1 Nuclear Power Plant. The forty year design life is not impacted considering both the
- original support system and modified (similar to Unit 2) support system. It 6-1
must be noted that the above conclusions are valid provided the Unit I surge line will have only one rigid support (H002) from the 1990 refueling outage ( onward, similar to the Unit 2 support system, and the system delta T for future operation will be limited to ( Ja.c.e. Operating precedures will be modified for Unit 1 to limit the system AT to ( )"'C. 0 4 4 t. 0
+
s' e G 6-2
o ERRATA [', i. t THE FOLLOWING PAGE OF WCAP-12218 CONTAINED ERRORS. CORRECTION OF THESE ERRORS L DOES NOT AFFECT THE CONCLUSIONS OF THE REPORT. 4
- THE CORRECTIONS ARE SHOWN WITH VERTICAL LINES ON THE RIGHT HAND BORDER.
4 l l I L l h e
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r o TABLE 4-1 f o FATIGUE CRACK GROWTH RESULTS FOR 10% WALL lh'!TIAL FLAW SIZE l'& i i 6
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Initial Initial Final (40 yr) Final flaw { Location Position Size (in) (% Wall) Size (in) (% Wall) l
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