ML17265A399
| ML17265A399 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 08/06/1998 |
| From: | Mecredy R ROCHESTER GAS & ELECTRIC CORP. |
| To: | Vissing G NRC (Affiliation Not Assigned), NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TAC-MA0389, TAC-MA389, NUDOCS 9808130298 | |
| Download: ML17265A399 (34) | |
Text
CATEGORY 1 REGULA Y INFORMATION DISTRIBUTIO SYSTEM (RIDS)
" ACCESSION NBR:9808130298 DOC.DATE: 98/08/06 NOTARIZED: NO FACIL:50-244 Robert Emmet Ginna Nuclear Plant, Unit 1, Rochester G
AUTH.NAME AUTHOR AFFILIATION MECREDY,R.C.
Rochester Gas 6 Electric Corp.
RECIP.NAME RECIPIENT AFFILIATION VISSING,G.S.
SUBJECT:
Submits response to NRC 980518 RAI re submittal for Leak-Before-Break approval for portions of RHR sys.
DXSTRIBUTION CODE:
A001D COPIES RECEIVED:LTR ENCL SIZE:
TITLE: OR Submittal:
General Distribution DOCKET ¹ 05000244 NOTES:License Exp date in accordance with 10CFR2,2.109(9/19/72).
05000244 E
RECIPIENT ID CODE/NAME PD1-1 LA VIS COPIES LTTR ENCL 1
1 1
1 RECIPIENT ID CODE/NAME PD1-1 PD COPIES LTTR ENCL 1
1 INTERN L: FILE CENTE EMCB NRR/DSSA/SPLB NUDOCS-ABSTRACT EXTERNAL: NOAC 1
1 1
1 1
1 1
1 1
1 NRR/DE/ECGB/A NRR/DRCH/HICB NRR/DSSA/SRXB OGC/HDS3 NRC PDR 1
1 1
1 1
1 1
0 1
1 D
C U
NOTE TO ALL "RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD)
ON EXTENSION 415-2083 TOTAL NUMBER OF COPIES REQUIRED:
LTTR 13 ENCL 12
C I
l V
'Ifll
'I p s '1 l
ANO Pti&
I ROCHESTER GAS ANDELECTRIC CORPORATION 89 EASTAVENIIE, ROCHESTER, N.Y. 14649-0001 AREA CODE 716-546-2700 ROBERT C. MECREDY Vice President Nuctear Operations August 6, 1998 U. S. Nuclear, Regulatory Commission Document Cohtrol Desk Attn:
Guy S. Vissing Project Directorate 1-1 Washington, D.C. 20555
Subject:
Response to Request for Additional Information (RAI)Related to Leak-Before-Break (TACNo. MA0389)
R. E. Ginna Nuclear Power Plant Docket No. 50-244 Ref. (1):
Letter from Guy S. Vissing (NRC) to Robert C. Mecredy (RGkE),
SUBJECT:
REQUEST FOR ADDITIONALINFORMATION RELATED TO "LEAK-BEFORE-BREAK EVALUATION OF PORTIONS OF THE RHR SYSTEM TO THE R. E. GINNANUCLEAR POWER STATION" (TAC NO.
MA0389), dated May 18, 1998
Dear Mr. Vissing:
By Reference 1, the NRC staff requested additional information regarding the submittal for Leak-Before-Break approval for portions ofthe residual heat removal (RHR) system for the R. E. Ginna Nuclear Power Plant. The attachment to this letter provides the requested information.
Very ly yours, Robert C. Mecredy Attachment xc:
Mr. Guy S. Vissing (Mail Stop 14B2)
Project Directorate I-1 Division ofReactor Projects UII Office ofNuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555
'st808i30298 980806 PDR" ADGCK 05000244 P
Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King ofPrussia, PA 19406 U.S. NRC Ginna Senior Resident Inspector
Responses to U.S. NRC Request for Additional Information Regarding Request Leak-Before-Break Approval Portions ofthe R.E. Ginna Nuclear Power Plant Residual Heat Removal System Piping (TAC MA0389)
uestion ¹1 Material Pro erties The information in Section 4.2 ofthe SI report indicated that ASME Code values were used for the Young's Modulus, yieldstrength, and ultimate strength.
However, as notedin Section 5.2 of MiVKG-1061, Vol. 3, when performing LBBanalyses, an emphasis isplaced on obtaining and using materials data from specimens mamifactured from the actual piping and weld materials used in thefacility.
Confirm that no materials test data existsfor the Ginna RHR piping or weld materials from the time offacilityfabrication. Ifno data exists, demonstrate when calculating the margin between the leakagegmv size and the criticalflcnv size that the use ofASME Code mininnim values provides a bounding analysis when compared to the use oftypical valriesfor the yieldand ultimate strengths for Type 316 stainless steel.
Res onse to uestion ¹I In performing the analyses, the possibility ofusing actual material properties for the Ginna RHR piping was explored but the properties were found to be unavailable.
Hence, it was decided to use ASME Code minimum properties to describe the stress-strain curve because it is believed that they are reasonably conservative for this type ofanalysis. It should be noted that for the J-R resistance curve, lower bound generic properties provided in the EPRI Ductile Fracture Handbook (Reference
The material properties (from Table 4-1 in SIR-97-077) are shown in Table 1-1.
Alternate material properties for typical piping materials and associated welds are provided in the EPRI Ductile Fracture Handbook.
These are attached in Appendix Aofthis document.
The generic stress-strain properties ofType 316 stainless steel provided in the EPRI Ductile Fracture Handbook and shown in Table 1-2 were used to recalculate the critical flaw sizes.
The J-R curve parameters for Type 316 stainless steel base metal is not provided in the EPRI handbook.
Hence
for this purpose, the J-R curve provided in Reference 2 was used.
This J-R curve is shown in Figure 1. As can be seen from this figure, the maximum crack extension associated with this J-R curve is 0.2 inches with a corresponding J of 12 in-k/in. In addition, the welds ofthe Ginna RHR piping were fabricated using SMAWwelding (Reference 6). Hence the properties ofSMAW weldments provided in EPRI Ductile Fracture Handbook and shown in Table 1-3 were also used to calculate the critical flaw size. The results ofthe analyses are provided in Table 1-4. It can be seen that the use ofthe alternate material properties for the Type 316 stainless steel resulted in very comparable results to those obtained in SIR-97-077 with the two alternate set ofproperties resulting in slightly larger critical flaw sizes.
The leakage through halfthe critical fiaw size was recalculated for the most limitingcritical flaw size (Node 680 on the hot leg) using the generic Type 316 stainless steel and SMAW properties and was found to be at least 5.0 gpm compared to 4.71 gpm obtained using the Code minimum properties in SIR-97-077, Rev. 0. In all cases, the leakage is within the detectable limits at Ginna as explained in Response to Question No. 6.
Table 1-1 Material Properties Used in SIR-97-077 for Type 316 Stainless Steel Property E (ksi)
(z, (=(zy) (ksi) o(ksi) an.w (ks>)
J~ (in-kipfin)
J (in-kipfin)
N Value 25,240 18.8 71.8 45.282 0.776 3.81 0.99 5.0 6.033 0.391
Table 1-2 Alternate Material Properties for Type 316 Stainless Steel [1,2]
Property E ksi a (ksi)
=G a.
ksi ag.
ksi Ji, in-ki /in J~ in-ki /in Value 25 500 29.6 58.1 43.85 12.0 4.80 10.7 12.0 36.3 0.594 Table 1-3 Material Properties for SMAW Stainless Steel Welds [1]
Property Value E ksi cr (ksi) 25,000 49.4 aksi anal ksi J~, in-ki /in
~
~
~
2 J
in-ki /in 61.4 55.4 9.00 9.80 0.99 5.0 6.033 0.391
Table 1-4 Critical Flaw Sizes and Leakage Using Alternate Material Properties Node No.
Hot Leg 680 50 60 70 Cold Leg 8400 910 920 930 950 960 From S1R 077 Rev. 0 10.967 11.499 11.432 12.552 12.065 10.390 11.498 12.436 13.456 14.358 Critical Flaw Size (in)
Using Generic Type 316 Stainless Steel Pro erties 11.498 12.005 11.934 12.975 12.524 10.956 11.996 12.868 13.815 15.502 Using Generic SMAW Weldment Pro erties 11.976 12.469 12.452 13.425 12.983 11.456 12.469 13.320 14.246 15.832
Crack Extension.
fn.
.04
.08
.12
.16
.20
.24 2500 6
~ 2000 o
1500 0
0 0
0 0
0 0
0 0
0 0
O 0
0 0
0 0
316 Stainless Steel Base Material E 1 TCT Specimen 561oK l 550 F)
Solid - Final H 16, 000 12,000 c
1.0 2.0 3.0 40 5.0 6.0 Crack Extension, ha, mm Figure 1. J-R Resistance Curve for Type 316 Stainless Steel [2]
uestion ¹2-Material Pro erties Submit the informationfrom Reference 9 to SIR-97-077 which supports the use oft'e C and n parameters in Table 4-1for establishing the J-resistance curve usedin this analysis.
Define what data was used to develop these fitparameters and the limitsofthe database used to develop t
the parameters, i.e. beyond what value ofcrack extension is the correlation no longer valid.
Res onse to uestion ¹2 The C and n parameters from Reference 9 ofSIR97-077, Rev. 0 (EPM Ductile Fracture Handbook) are shown in Appendix Aofthis document.
The parameters are those associated with SMAWweldments. Itwas indicated in the EPRI Ductile Fracture Handbook that these parameters were obtained from Reference 3, which provides the technical basis for flaw evaluation ofaustenitic steel piping in ASME Code Section XI. J versus crack extension data for the SMAW material was not provided in Reference 3 but the material J-T curve was provided which indicated that the maximum J obtained from the data is approximately 3 in-kip/in.
The maximum value ofapplied J computed in the evaluation was 4 to 4.5 in-kip/in. The J-R resistance curve beyond 3 in-kip/in was determined by applying the power law function describing the J-R curve (using the J-R curve parameters shown in Table 4-1 ofSIR-97-070).
This approach is different from the extrapolation technique recommended in NUI&G-1061, Vol. 3, page A-20. Application ofNUREG-1061 extrapolation technique does not change the critical flaw by any significant amount (less than 2% at the most critical location).
uestion ¹3 Material Pro erties Erplainwhether or not the data used to develop the material J-resistance curve addresses the issue ofthermal aging ofstainless steel pipe welds.
For reference, the staffhas examined the informationfrom NURIEGICR-6428, "Lffectsof Thermal Aging on Fracture Toughness and Charpy-Impact Strength ofStainless Steel Pipe 8'elds, "May 1996.
This information appears to indicate thatfor welds manufactured by the same processes (submerged arc welding or shielded metal arc welding) as those used to fabricate the Ginna RKR line welds, moderate decreasesin fracture resistance are to be expected and that a loi er boimd J-resistance curve to the available data should be more conservative than that defined by the C and n values of Table 4-1.
Res onse to uestion ¹3 As explained in the response to Question ¹2, the J-resistance curve used in the analysis is consistent with that used for the flaw acceptance criteria in ASME code Section XI. The issue of thermal aging was not specifically addressed for this curve in Reference 3. As indicated in NUREG-6428, however, the fracture resistance ofthe fluxed welds is only minimally affected by aging since the fracture toughness is dependent on the inclusions in the welds rather than the kinetics associated with embrittlement during long-term thermal aging.
Based on the small differences in the critical flaw size between the different alternate material properties considered in the response to Question No. I, it can be expected that the very small change in the J-R curve due to thermal aging ofthe weld willnot affect the conclusions ofthe evaluation.
uestion ¹4 Material Pro erties Co>ifirm that none ofthe pipingforwhich LBBapprovalis sought was manufactured with cast stainless steel (e.g., elbows). Ifthere are cast sections, evaluate their material properties and address concerns regarding the aging ofcast stainless steels inyour evaluation.
Res onse to uestion ¹4 Review ofthe specifications used in the purchase and installation oforiginal RHR piping and fittings (Reference 4) revealed that no cast stainless steel components were provided for the RHR system.
Seamless or forged piping and fittings were used.
10
uestion ¹5-Pi in Geomet Itappears that ASME Code nominal valrres were usedfor Schedule 160 piping diameters and wall thickness (8.50 inch ID, l.125 inch wall thickness,
- 10. 75 inch OD). Explain why the use of these values provides a bounding analysis for the Ginna RKRpipingifas-built or as fabricated dimensions are not available. As notedin question Pl above, the staffconsiders the use ofas-built'imensions, when possible, to be the most appropriate values to rrse in LBBanalyses and requires that conservative values be rrsed ifinsufficient as-built data is available. Ifthe values used in the SI analysis do not provide a bounding assessment ofthe margin between the leakage and criticalfluvsizes, provide a reanalysis ofthe Ginna RHR piping or a sensiti vitystudy to demonstrate the effect ofnon-nominal wall thickness orpiping diameters on the conclusions.
Res onse to uestion ¹5 Since the as-built dimensions ofthe Ginna RHR piping are unavailable, a sensitivity analysis was performed to determine the effect ofnon-nominal pipe geometry on the LBB evaluation.
The minimum pipe thickness acceptable per ASME Code Section IIIis 0.875 t,; i. This thickness was used to recalculate the stresses for the LBB evaluation.
The reduction in the pipe thickness resulted in higher stresses.
Another evaluation was also performed with pipe thickness of 1.125 t,,; i to investigate the effect ofan increased pipe thickness.
The results ofthe critical flaw size determination and leakage through halfofthe critical flaw sizes for these two cases are presented in Table 5-1. The evaluation was performed using the material properties shown in Table 4-1 of SIR-97-077.
Leakage was calculated through halfthe critical flaw size at Node 680 for the two pipe thicknesses (0.875 t,; i and 1.125 t,;
>) and were found to be 5.1 gpm and 4.3 gpm compared to the nominal value of4.71 gpm. The difference in leakage between the various pipe thicknesses is relatively small considering the leakage detection capability at Ginna as explained in the response to Question ¹6.
11
Table 5-1 Critical Flaw Sizes and Leakage for Various Pipe Thicknesses Node No.
Hot Leg 680 50 60 70 Cold Leg 8400 910 920 930 950 960 From SIR-97-077, Rev. 0 t 10.967 11.499 11.432 12.552 12.065 10.390 11.498 12.436 13.456 14.358 Critical Flaw Size (in) 0 875 tnomisal 10.335 10.811 10.765 11.977 11.471 10.078 11.160 12.085 13.128 13.753 t=1.125 t,; i 11.430 11.988 11.903 12.960 12.491 11.239 11.679 12.627 13.629 15.546 12
uestion¹6-Lenkn eMnr in As nofedin fhe srrbmittal, the staffhas published guidance in NURI:G-1061, Vol. 3 regarding issues to be considered in the applicalion ofLeak-Before-Break (LBB) calculations. In Section
- 5. 7 ofthe NUREG, regarding fhe size ofthe postulated through-wall leakage flmvto be usedin the evaluali on, lhe staffnoted, "The margin on rhe magnitude ofthe leakage applicable to high energy fluidsyslem piping... should be no less than afactor of10 or greater fhan the capability ofthe leakage detection systems used and adequate sensitivity and reliabilityofthe leakage detecfion syslem should be demonstrated " Itis the staff's position thaf fhisfactor ofsafety mrrst be included without modification in LBBanalyses.
The srrbmiftal states on page 5-8 thai, "... the leakage detecfion system at Ginrra...is capable of measuring 1 gpm leakage.... " Therefore, the appropriate leakage flcnv size for the LBBanalysis would be thafflcnvwhich is shown to leak at a rate of10 gpm.
The crilicalflcnv size calcrrlafed from examining SSL loading condition should then be afaclor of2 greater than the leakage flcnv.
Based upon fhe results submitledin Table 5-2 (page 5-10), ifappears that your calculations have demonstraled thaiforRHR hot leg nodes 680, 50, 60, and 70 that aflaw one-half ofthe crilicalflaw size leaks at rates behveeir 4. 71 and 5. 74 gpm.
Therefore, whileyour analysis
'fixes" the factor of2 behveen fhe crilicaland leakage flcnv sizes, it does nof appear that a factor of10 on the leakage is maintained.
Vice versa, based on the plotprovidedin Figrrre 5-2, itappears that your calculations predict that itwould require aflcnv behveen 7 and 7.5 inchesin length to cause 10 gpm ofleakage.
Since the criticalflaw size that you calculated for the subj ect piping nodes was between 10.97 and 12.55 inches, afactor of2 behveen the leakage and critical flaw sizesis not achieved.
Determine what size flcnvprovides for 10 gpm ofleakage at each analyzed location in both the hot and cold legs and demonstrate fhe criticalflcnv size exceeds fhe 10 gpm leakage flawsize by afactor of2.
13
Demonstrate that the leakage flaw determinedin (a) "...willnot experience unstable crack growth even iflarger loads (at least the ~2 times the normal plus SS1" loads)... " Isee NUREG 1061, Vol. 3, pg. 5-3, item (I)J are applied.
Res onse to uestion ¹6 The first part ofthe question willbe answered based on results shown in Table 5-2 ofthe submittal (SIR-97-077, Rev. 0) and the margin requirements in Section 5.7 ofNUREG-1061, Vol. 3. RHR hot legs nodes 680, 50, 60, and 70 have one halfofthe critical flaw size length leakage between 4.71 and 5.74 gpm. Taking the minimum leakage rate of4.71 gpm for conservatism, and applying the margin factor of 10, the minimum leakage detection requirement becomes 0.471 gpm.
Reference 5 gives details ofthe capabilities ofGinna le'ak detection systems.
Ofparticular importance are the systems outlined below.
1.
Containment AirParticulate Monitor, R-11 This is the most sensitive instrument available for detection ofReactor Coolant System (RCS) leakage in containment. It is capable ofdetecting low levels ofradioactivity in containment air.
Assuming complete dispersion ofleaking radioactive solids consistent with very littleor no fuel cladding leakage, R-11 is capable ofdetecting leaks as small as approximately 0.013 gpm (50 cm'/min) within 20 minutes.
Even ifonly 10% ofthe particulate activity is actually dispersed, leakage rate ofthe order of0.13 gpm are well within detectable range ofR-11, which is much lower than the minimum leakage detection requirement of0.471 gpm.
2.
Liquid Inventory in Process System Leakage can also be detected by unscheduled increase in the amount ofreactor coolant makeup water required to maintain the normal level in the pressurizer.
Based on frequency ofinventory 14
balance and volume control tank level instrumentation, the charging system inventory method of leak detection can detect a 0.25 gpm leak which is about halfthat ofthe minimum leakage detection requirement of0.471 gpm.
3.
Condensate Measuring System This system employs the Containment Recirculation Fan Coolers (CRFCs) cooling coils to collect condensate from the containment air that comes offthe RCS, and deposited into a drain pan equipped with a standpipe and instrumentation that measures accurately the water level condensate flowfrom 1 gpm to 30 gpm. Flows less than 1 gpm can be measured by periodic observation oflevel change in the standpipe.
This is a useful backup to the two leak detection systems that can support the minimum leakage requirement of0.471 gpm.
4.
Other Systems Other leak detection systems that can detect higher leakage capacities include:
- a. Radiation Monitor, R-12 which can detect 2 gpm to 4 gpm in less than 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.
- b. HumidityDetectors This system can detect vapor originating from all sources, i.e.,
not only from RCS, but from main steam and feedwater systems.
Capable ofdetecting 2 gpm to 10 gpm.
In response to the second part ofthe question, it was noted in SIR-97-077, that the criterion based on a safety factor of2 on flaw size is bounding compared to the criterion based on a safety factor of~2 on stresses.
To demonstrate this, the critical flaw sizes were recalculated with the material properties issued in Table 4-1 ofSIR-97-077.
The critical flaw sizes for this case are shown in Table 6-1. It is shown that at all the node locations, the critical flaw size based on a safety factor of~2 on stress is greater than halfthe critical flaw size based on a safety factor of 15
one on the stresses.
This indicates that the latter is bounding in all cases since it willresult in the minimum leakage.
16
Table 6-1 Comparison ofCritical Flaw Sizes with a Safety Factor of Unity and ~2 on Stresses Node No.
Hot Leg 680 50 60 70 Cold Leg 8400 910 920 930 950 960 HalfCritical Flaw Size With Safety Factor ofUnity on Stress (in.)
5.483 5.750 5.716 6.276 6.032 5.195 5.749 6.218 6.728 7.179 Critical Flaw Size With Safety Factor of~2 on Stress in.
7.950 8.524 8.453 9.683 9.156 7.322 8.524 9.555 10.692 11.601 17
uestion 07 Critical Crack Size Determination Provide additional explanation regarding the criteria used to determine the criticalflawsize for each location in the analysis. Inparticular, explain what is meant by the statement beginning on page 5-2, "Crack extensions during stable ductile tearingin the EPFM analyses are conservatively not included in the criticalflaw length computations. "Does this imply that stable crack growth beyond Jic is not includedin the determination ofthe criticalflaw size?
Res onse to uestion Ii7 The J-Integral/Tearing modulus evaluation methodology which considers stable ductile tearing beyond Jic was used to determine the critical flaw sizes. The J-R material resistance curve presented in Table 4-1 ofSIR-97-077 was converted to a J-T material curve where the Tearing Modulus (T) is defined as:
dJ E
T=a-da o
2 0
where dJ/da is the slope ofthe J-R curve, E is the modulus ofelasticity and [, is the reference stress (assumed to be the flow stress).
The applied J versus a curve is also converted into a J-T curve. The intersection ofthese two curves represents the point ofinstability and the crack size at this instability point is the critical flaw size. An example ofthe critical flaw size determination is shown in Figure 7-1.
The statement "Crack extensions during stable ductile tearing in the EPFM analyses are conservatively not included in the critical flaw length computations" on page 5-2 in the report is misleading and is subsequently clarified above.
18
InstablilityAnalysis c 4 CL 3
L2
~ 1-
+
crack incre material 0
200 400 600 800 1000 1200 1400 Tearing Modulus Figure 7-1.
Determination ofCritical Flaw Size Nuclear Remote Tension for Node 680 19
uestion ¹8 Critical Crack Size Determination Submit the formula used to determine the criticalflawsize under bending loads alone and any necessary parameters to be used in the calculation. Thisformula is alluded to on page 5-2 andis integral to your evaluation given the manner in whichyou propose to arrive at the criticalflaw size under combined tension and bending loads (see question ¹9 below).
Res onse to uestion ¹8 The expression for the J-integral for a through-wall crack under bending from Reference 11 of SIR-97-077, Rev. 0 is given by J = f, a
+ ua.a.
h,,n, The parameters in the above equations are the same as the tension loading case except applied moment = a I/R o=
remote bending stress in the uncracked section I,=
Second moment ofinertia ofthe uncracked cylinder about the neutral axis M,
=
limitmoment for a cracked pipe under pure bending corresponding to n = Oo (elastic-perfectly plastic case)
M. Cos Sin(y)
'y 2
2 M,
limitmoment ofthe uncracked cylinder = 4a, R't 20
uestion ¹9 Critical Crack Size Determination Given that you have calculated a criticalflaw under simple tension loading and under simple bending loading scenarios justify the technique (shown in the top equation on page 5-3 ofthe SI report) used to determine thefinalcriticalflaw size by linear interpolation ofyour tension loading and bending loading solution. Dentonstrate that this method provides either an exact solutionfor the criticalflawsize under combined loading or that conservatively estimates the criticalflaw length or submit a reference in which this is demonstrated.
Res onse to uestion ¹9 Alternate models for circumferential through-wall flaws under remote tension, remote bending and combination oftension and bending are provided in the EPRI Ductile Fracture Handbook (Reference 1). Solutions are provided in this handbook for pipe radius to thickness (R/t) ratios of 5, 10 and 20 for the remote tension and remote bending cases.
However, for combined tension and bending cases, solutions are provided only for R/t = 10 which is different for the piping geometry at Ginna. It is for this reason that the simple linear interpolation scheme in SIR-97-077 was used.
To determine the reasonableness ofthis approach, the models in the EPRI handbook for R/t = 10 were used to determine the critical flaw sizes for remote tension, remote bending and various combination ofthe tension and bending stresses.
The parameters used for the evaluation are:
E
=
25,240 ksi a,
=
18.764 ksi a
=
0766 n
=
2and5 C
=
6.033 in-kip/in N
=
0391 Jic
=
0.99 in-kipfm 21
The results are presented in Figures 9-1 and 9-2 for combined stresses of 10,15 and 20 ksi. In these figures "T+B" refers to the combined tension and bending solution from the EPRI handbook and "Interpolation" refers to the linear interpolation scheme used in SIR-97-077, Rev. 0. It can be seen that in all cases the critical flaw sizes obtained using the linear interpolation k
scheme in SIR-97-077, Rev. 0 is bounded by that obtained using the combined tension and bending model or very closely matches it. For the cases where the stresses were assumed to be either all remote tension or bending, the critical flaw sizes obtained with the pc-CRACK program matched those obtained using the alternate model from the EPRI Ductile Fracture Handbook.
To further illustrate the reasonable ofthe linear interpolation scheme, limitload solution provided in ASME Section XItechnical basis document (Reference 3) was used to determine the allowable through-wall crack length under various combination oftension and bending stresses.
In this evaluation, a pipe with outside diameter of 10.75 inches and flow stress of 51 ksi was used. Z factor consistent with that in Reference 3 for SMAW material was used.
The results ofthe analysis are shown in Figure 9-3. It can be seen that in this case also, linear interpolation ofthe pure tension and bending cases gives conservative results compared to the actual combined tension and bending solution shown in Figure 9-3.
22
8 S=10 ksi T+B Model o
6.
ttJ U)
Q) 4 o
~
0I a$
Interpolation S= 3 5 ksi T+8 Model Interpolation S=20 ksi T+B Model Interpolation n=5 0
0.1 0.2 0.3 OA 0.5 0.6 0.7 0.8 0.9 Tensile Stress/Total Stress Figure 9-1. Comparison ofSolution for Critical Flaw Size Using Exact Solution for Combined Tension and Bending With Linearly Interpolated Values (n = 5) 23
8 S =10 ksi T+B Model o
6 l5 5
U)
Ql 4
o 6$
O J3 6$
Interpolation S=15 ksi T+B Model Interpolation S =20 ksi T+ B Model interpolation n=2 0
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 Tensile Stress/Total Stress Figure 9-2. Comparison ofSolution for Critical Flaw Size Using Exact Solution for Combined Tension and Bending With Linearly Interpolated Values (n = 2) 24
12 s =5ksi s = 10ksi s =15ksi s = 20ksi 0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Tensile Stress / Total Stress Figure 9-3. Critical Flaw Size Calculated using LimitLoad for Combined Tension and Bending Stresses 25
REFERENCES l.
EPRI Report NP-6301-D, "Ductile Fracture Handbook," June 1989.
2.
EPRI Report No. NP-4768, "Toughness ofAustenitic Stainless Steel Pipe Welds,"
October 1986.
3.
"Evaluation ofFlaws in Austenitic Steel Piping," Prepared by the Section XITask Group for Piping Flaw Evaluation, ASME Boiler and Pressure Vessel Code Committee, EPRI Report NP 4690-SR, April 1986; see also ASME J. Pressure Vessel Technology, Vol.
108, 1986, pp. 352-367.
4.
RG8cE Technical Specifications (Westinghouse Electric Corp., Contra'ctor), SP-5291, 12/23/67, Line Specification No. 2501.
5.
Ginna UFSAR, Rev. 14, Section 5.2.5, "Detection ofLeakage Through Reactor Coolant Pressure Boundary".
6.
Bechtel Corporation, Welding Standard, Procedure Specifications P8-AT-g ("Y"Type Insert Ring), Rev. 0, March 22, 1967; P8-AT-g, Rev. 3, Feb. 23, 1967.
26
Appendix A Material Properties from EPRI Ductile Fracture Handbook EPRI NP-6301-D, Vol. 3 SIR-98-071, Rev.
1 A-0
0 DUCTILE ERACTURE HANDBOOK (in three volumes)
VOLUME 3 Research Project 1757-69 January 1991 Prepared by AKRAM ZAHOOR Prepared for NOVETECH CORPORA TION P.O. Box 7605 Gaithersburg, MD 20898-7605 and ELECTRIC POM/ER RESEARCH INSTlTUTE 3412 HillvietivAvenue Palo Alto, CA 94304 EPRI Project Manager S. N Tagart, Jr.
Nuclear Power Division Structural IntegrityAssociates, Inc.
Tnll r
0 rl 0
Table 13-1 Ramberg-Osgood Stress-Strain Parameters Material Temp.
oF ao ksi
~u ksi E
Ref.
10 psi A106 GR B A106 GR C A516 GR 70 Generic CS TP304 SS TP304 SS TP304 SS TP304 SS TP304 SS TP304 SS TP304 SS TP316SS Generic SS/
SMAW TP304 SS/
SAW 8 SMAW Generic SS/
SAW A508 Cl 3 120 550 550 550 75 70 70 68 572 550 550 550 550 3.80 4.00 2.51 4.20 2.51 4.20 2.51 4.20 4.70 3.80 9.16 3.20 3.82 5.04 3.46 5.68 2.04 3.87 11.00 6.90 7.30 8.90 12.00 4.80 9.00 9.80 37.00 27.10 27.10 27.10 34.50 45.30 34.70 39.30 24.50 33.70 23.70 29.60 49.40 71.70 27.0 60.00 26.0 60.00 26.0 60.00 26.0
'9.70 28.3 0
30.0 28.3 28.3
'5.6 50.50 25.5 63.10 25.5 58.10 25.5 61.40 25.0 2
3 3
4,8 3
16 10 10 10 3
3, 20 3
3,7 600 78.310 102.98 28.0 1 8 550 3.39 6.89 44.80 67.20 25.5 3
550 U 00 6.90 33.700 50.50 25.0 3, 7 13 ~ 1-3 Structural IntegrityAssociates, Inc.
rn R
l 0
M ri Table 13-2 J - Resistance Curve Data 1
Material Temp.
Thick.
J; Co F
inch in-Ibfin in-Ib/in C1 in-Ibfin Ref.
Generic CS-1 Generic CS-2 Generic CS-3 TP304 SS Generic SS/
SMAW Generic SS/
SAW A508 CI3 A106 GR 82 TP304 SS 550 1.0 550 1.0 550 1.0 75 1.0 550 1.0 550 1.0
, 550 1.378 120 75 650 0.0 446 2,900 8,000 0.0 0.0 0.0 350 0.0 600 0.0 1,050 0.0 6,500 0.0 990 0.0 1,808 2,563 5,400 32,758 6,033 0.277 4, 21 0.274 4, 21 0.344 4, 21 0519 3
0 391 3,7 3,443 13,008 33,642 0.329 19, 18 0.334 2
0 435 3
4,448 0.431 3, 7 Notes:
- 1. J=Co + C1
~ (ha)"
where J and ha have in-Ibfin and inch units, respectively.
2.
8 inch pipe, 0.54 inch wali thickness 3.
4 inch pipe, 0.34 inch wall thickness 1
~ ~
Structural Integrity Associates, Inc.