ML032690649
| ML032690649 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 08/26/2003 |
| From: | Entergy Nuclear South, Entergy Operations |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| CNRO-2003-00033 M-EP-2003-002, Rev. 1 | |
| Download: ML032690649 (29) | |
Text
ENCLOSURE 2 CNRO-2003-00033 ENGINEERING REPORT M-EP-2003-002, REV. 1 FRACTURE MECHANICS ANALYSIS FOR THE ASSESSMENT OF THE POTENTIAL FOR PRIMARY WATER STRESS CORROSION CRACK (PWSCC)
GROWTH IN THE UNINSPECTED REGIONS OF THE CONTROL ELEMENT DRIVE MECHANISM (CEDM) NOZZLES AT ARKANSAS NUCLEAR ONE UNIT 2
Engineering Report No.
M-EP-2003-002 Page I
Rev.
01 of 62
-- Entfefy ENTERGY NUCLEAR SOUTH Engineering Report Coversheet Fracture Mechanics Analysis for the Assessment of the Potential for Primary Water Stress Corrosion Crack (PWSCC) Growth in the Un-nspected Regions of the Control Element Drive Mechanism (CEDM) Nozzles at Arkansas Nuclear One Unit 2 Engineering Report Type:
New Revision X
Deleted rJ Superceded 0
Applicable Site(s)
ANO X
Echelon X
X ENS 0
Vendor Safety-Related:
X 0
Yes No Vendor Document No.
Prepared by:
Verified/
Reviewed by:
Approved by:
Comments:
Date:
Vr El Yes No Date: '/a,/e3 go No Date:
El Yes Em-qo Attached:
O Yes No O Yes 0 Yes No Responsible supervisor or Responsible Central Engineering Manager (for multiple site reports only)
Engineering Report M-EP-2003-002 Rev. 01 Page 2 cf 62 E-M-EP-2003-002 Engineering Report No.
01 Rev. _
of 62 Page 2
RECOMMENDATION FOR APPROVAL FORM Comments:
Attached:
El Yes
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Prepared by:
- j, ev a, Ace
.&&f/XL, gIV 6 n
ResporlJngineer Concurrence 4
- AE Rsponsible Engineering Manager, ANO El No Date:
/2LJS El Yes
. -T-T -
[
No El No El Yes E
No Not Applicable Concurrence:
Concurrence:
Responsible Engineering Manager, GGNS Not Applicable Responsible Engineering Manager, RBS Date:
Date:
El Yes El No E Yes No El Yes No El Yes No El Yes No El Yes No Not Applicable Concurrence:
Date:
Responsible Engineering Manager, WF3
Engineering Report M-EP-2003-002 Rev. 01 Page 3 of 62 Table of Contents Section Title Page Number List of Tables 3
List of Figures 4
List of Appendices 6
1.0 Introduction 7
2.0 Stress Analysis 11 3.0 Analytical Basis for Fracture Mechanics and Crack 33 Growth Models 4.0 Method of Analysis 38 5.0 Discussion and Results 43 6.0 Conclusions 60 7.0 References 61 List of Tables Table NumberX Title Page Number I
Nodal Stress data for 00 Nozzle.
17 2
Nodal Stress data for the 8.80 nozzle at the downhill location.
18 3
Nodal Stress data for the 8.80 nozzle at 22.50 rotated from the downhill 19 location.
4 Nodal Stress data for the 8.80 nozzle at 450 rotated from the downhill 20 location.
5 Nodal Stress data for the 8.8° nozzle at 67.50 rotated from the downhill 21 location.
6 Nodal Stress data for the 8.80 nozzle at the Mid-Plane location.
22 7
Nodal Stress data for the 8.80 nozzle at the uphill location.
23 8
Nodal Stress data for the 28.80 nozzle at the downhill location.
24
Engineering Report M-EP-2003-002 Rev. 01 Page 4 of 62 List of Tables (continued)
Table Number Title Page Number 9
Nodal Stress data for the 28.80 nozzle at 22.50 rotated from the downhill 25 location.
10 Nodal Stress data for the 28.80 nozzle at the Mid-Plane location.
26 11 Nodal Stress data for the 28.80 nozzle at the uphill location.
27 12 Nodal Stress data for the 49.60 nozzle at the downhill location.
28 13 Nodal Stress data for the 49.60 nozzle at 22.50 rotated from the downhill 29 location.
14 Nodal Stress data for the 49.60 nozzle at 450 rotated from the downhill 30 location.
15 Nodal Stress data for the 49.60 nozzle at the Mid-Plane location.
31 16 Nodal Stress data for the 49.60 nozzle at the uphill location.
32 17 Comparison of Fracture Mechanics Models 48 18 Results for compression zone 49 19 ANO-2 As-Built Analyses Results Summary 51 20 Results from Additional Analysis 56 21 Boundaries for Augmented Inspection 57 List of Figures Figure Title Page Number Number 1
Details of guide-cone connection to CEDM [2]. Detail extracted from 8
Drawing M-2001-C2-107 [2 2
Sketch of a typical inspection probe sled [3a].
9 3
Estimated as-built nozzle configuration based on evaluation of the UT and 1 2 design data.
4 Hoop Stress contours for the 0° nozzle.
14 5
Hoop Stress contours for the 8.80 nozzle.
14 6
Hoop Stress contours for the 28.80 nozzle.
15 7
Hoop Stress contours for the 49.60 nozzle.
15 8
Plot showing hoop stress distribution along tube axis for the 00 nozzle.
17 9
Plot showing hoop stress distribution along tube axis for the 8.80 nozzle at 1 8 the downhill location.
1 0 Plot showing hoop stress distribution along tube axis for the 8.80 nozzle at 1 9 22.50 rotated from the downhill location.
11 Plot showing hoop stress distribution along tube axis for the 8.80 nozzle at 20 450 rotated from the downhill location.
Engineering Report M-EP-2003-002 Rev. 01 Page 5 of 62 List of Figures (Continued)
Figure Title Page Number Number 12 Plot showing hoop stress distribution along tube axis for the 8.8° nozzle at 21 67.50 rotated from the downhill location.
13 Plot showing hoop stress distribution along tube axis for the 8.80 nozzle at 22 the Mid-Plane location.
14 Plot showing hoop stress distribution along tube axis for the 8.80 nozzle at 23 the uphill location.
15 Plot showing hoop stress distribution along tube axis for the 28.80 nozzle 24 at the downhill location.
16 Plot showing hoop stress distribution along tube axis for the 28.80 nozzle 25 at 22.50 rotated from the downhill location..
17 Plot showing hoop stress distribution along tube axis for the 28.80 nozzle 26 at the Mid-Plane location.
18 Plot showing hoop stress distribution along tube axis for the 8.80 nozzle at 27 the uphill location.
19 Plot showing hoop stress distribution along tube axis for the 49.60 nozzle 28 at the downhill location.
20 Plot showing hoop stress distribution along tube axis for the 49.60 nozzle 29 at 22.50 rotated from the downhill location.
21 Plot showing hoop stress distribution along tube axis for the 49.6 nozzle 30 at 450 rotated from the downhill location.
22 Plot showing hoop stress distribution along tube axis for the 49.60 nozzle 31 at the Mid-Plane location.
23 Plot showing hoop stress distribution along tube axis for the 49.60 nozzle 32 at the uphill location.
24 SICF shown as a function of normalized crack depth for the a-tip" 34 and the mc-tip" 25 Curve fit equations for the extension and bending" components in 37 Reference 8.
26 Plots showing effect of nodal data selection on the accuracy of 41 polynomial regression fit, 27 Comparison of SICF for the edge crack configurations with the 46 membrane SICF for current model.
28 Comparison of SIF for the current model and conventional model.
47 29 SIF comparison between current model and conventional model.
48 30 Crack growth and SIF for 0° nozzle - OD surface crack.
52
Engineering Report M-EP-2003-002 Rev. 01 Page 6 of 62 List of Figures (Continued)
Figure Title Page Number Number 31 Crack growth and SIF for 00 nozzle - Through-wall axial crack.
53 32 Crack growth and SIF for 8.80 nozzle - OD surface crack.
53 33 Crack growth and SIF for 8.80 nozzle - Through-wall axial crack.
54 34 Crack growth and SIF for 28.80 nozzle - OD surface crack.
54 35 Crack growth and SIF for 28.80 nozzle - Through-wall axial crack.
55 36 00 Nozzle crack growth at a lowered reference line at 1.25 inches 58 above nozzle bottom.
37 8.80 Nozzle crack growth at blind zone elevation of 1.544 inches 58 above nozzle bottom at an azimuth of 67.50.
38 28.80 Nozzle crack growth at blind zone elevation of 1.544 inches 59 above nozzle bottom at an azimuth of 22.50.
39 49.60 Nozzle crack growth at blind zone elevation of 1.544 inches 60 above nozzle bottom at an azimuth of 450.
List of Appendices Appendix Content of Appendix Number of Number Attachments In Appendix A
Design, UT probe characterization, UT analysis results, and 6
evaluation for as-built configuration B
Mathcad worksheets annotated to describe the three models 3
C Mathcad worksheets for ANO-2 Analyses 48 0
Verification and Comparisons (Mathcad worksheets) 4
- 1) Attachment number 32 is intentionally blank, but is included to keep the sequence in order.
Note:- This document {revision 1) was revised to:
- 1) Make it ANO-2 specific.
- 2) Revise finite element models and re-analyze residual stresses.
- 3) Change the surface crack fracture mechanics models.
- 4) Define augmented inspection regions.
Engineering Report M-EP-2003-002 Rev. 01 Page 7 of 62 1.0 Introduction The US Nuclear Regulatory Commission (NRC) issued Order EA-03-009 [1],
which modified licenses, requiring inspection of all Control Element Drive Mechanism (CEDM), In-Core Instrumentation (ICI), and vent penetration nozzles in the reactor vessel head. Paragraph IV.C.1.b of the Order requires the inspection to cover a region from the bottom of the nozzle to two (2.0) inches above the J-groove weld. In the Combustion Engineering (CE) design the CEDM nozzles have a guide-cone attached to the bottom of each CEDM. Figure 1 [2] provides a drawing showing the attachment detail and a sketch showing the typical CEDM arrangement in the reactor vessel head. The attachment is a threaded connection with a securing set-screw between the guide-cone and the CEDM nozzle. The CEDM nozzle is internally threaded and the guide-cone has external threads. Thus, the CEDM nozzles in the region of attachment, including the chamfered region, become inaccessible for Ultrasonic Testing (UT) to interrogate the nozzle base material. The design of the UT probes result in a region above the chamfer (0.200 inch [reference 3a &3b]) that cannot be inspected. Therefore, the region of the CEDM base metal that can be inspected begins at about 1.544 inches above the bottom of the CEDM nozzle and extends to two (2.0) inches above the J-groove weld. The unexamined length (here after called the blind zone) constitutes the threaded region, the chamfer region, and the UT dead zone (1.250 + 0.094 + 0.200). The terms used in this report are defined as follows:
Freespan = (bottom of weld - blind zone); this area below the weld is accessible for volumetric examination.
Propagation Length = (bottom of weld -top of crack tip); area available for crack growth.
Note:- for an outside diameter (OD) surface crack, this length is always less than the freespan; for through-wall it is equal to the freespan; and, for an inside diameter (ID) surface crack, the criterion is the propagation length and a through-wall penetration condition.
Augmented Inspection Area: The axial and circumferential extent of the CEDM below the blind zone subject to an OD surface examination to ensure sufficient region for crack growth in one (1) cycle of operation without compromising the weld. This region may include weld material when the weld extends into the blind zone.
The nozzle as-built dimensions were determined by a detailed review of applicable design drawings and UT data from the previous inspection, which are provided as an attachment in Appendix A. The results of this assessment was used to develop the finite element model which obtains the prevailing stress distribution (Residual+Operating) used in the deterministic fracture mechanics analyses. The deterministic fracture mechanics analyses, in turn, assess the potential for primary water stress corrosion cracking (PWSCC) in the blind zone of the nozzles. This aspect is discussed in more detail in Section 2.
i Engineering Report M-EP-2003-002 Rev. 01 Page 8 of 62 In order to exclude the blind zone from the inspection campaign, a relaxation of the Order is required pursuant to the requirements prescribed in Section IV.F and footnote 2 of the Order [1].
The purpose of this engineering report is to:
- 1. Determine if sufficient area between the blind zone and the weld exists to facilitate one (1) cycle of axial crack growth without the crack reaching the weld, and
- 2. For nozzles not meeting 1 above, determine how much of the blind zone combined with the available freespan is required to facilitate 1 cycle of crack growth without the crack reaching the weld. This area is subject to augmented surface examination.
DETAIL "A"
CED NOZZIE T YPI C CEOM NOZZLE
[oL TAIL GUII[ CONE DETAIL a
b C
CEDI Noe Figure 1:
Details of guide cone connection to CEDM12). A Hea sketch of a typical CEDM connection showing regions of interest is provided.
a) CEDM nozzle tube.
b)
Details of the chamfer in the machined Cladga recess of the threaded region. Provides Irtspet dimensions for the threaded and chamfer Regll regions.
I c)
Details of guide-cone connection to CEDM Pn'Pag.Jn Leng
[2].
Ln d) Sketch of a typical CEDM penetration BlincZone
- 154, showing the region of interest Detail extracted from Drawing M-2001-C2-23 (ANO-2) [2). The threaded region in the CEDM is 1.344 inches (Threads plus Recess plus WideCone chamfer).
Id
Engineering Report M-EP-2003-002 Rev. 01 Page 9 of 62 The detail of the guide-cone-to-CEDM connection shows that the threaded +
chamfer region is 1.344 inches in height. The UT dead band, determined to be 0.200 inch above the top of the threaded plus chamfer region in the CEDM, is based on a typical inspection probe sled design [3b] (shown in Figure 2).
CEDM Nozzle-0.200' Dead Bn 0
0 Threaded connection and Chamfer Region UT Inspection Probe Schematic - See Table Below For Transducer Information PositionX Mode Diameter-Description 1
Transmit 0.25" Circumferential Scan Using TOFD 2
Receive 0.25" Circumferential Scan Using TOFD 3
Transmit 0.25" Axial Scan Using TOFD 4
Receive 0.25" Axial Scan Using TOFM 5
Transmit 0.25" Standard Zero Degree Scan Receive 6
LFEC NA Low Frequency Eddy Current Probe 7
EC NA Standard Driver/Pickup Eddy Current Probe Figure 2: Sketch of a typicalinspection probe sled[3a]. The UTdead bandis shown with respect to the thread + chamfer region Based on the probe design and the geometry of the nozzle at the threaded connection, the explanation provided in Reference 3b shows the UT dead band to
Engineering Report M-EP-2003-002 Rev. 01 Page 10 of 62 extend 0.200 inch above the chamfer region immediately above the threads.
Therefore, to account for the thread region, chamfer and the UT dead band, the blind zone height is determined to be 1.544 inch (1.250" + 0.094" + 0.2") above the bottom of the nozzle.
The analysis used to determine the impact of not examining the blind zone independently evaluates a part through-wall axial crack initiated from the ID, a part through-wall axial crack initiated from the OD, and a through-wall axial crack.
Part Through-Wall Cracks The initial crack depth obtained from Reference 4 is 0.04627 inch deep for an ID axial crack and 0.07932 inch deep for an OD axial crack. The crack length is based on the detected length of 4 mm (0.157 inch) from Reference 4. In the deterministic fracture mechanics analyses, the part through-wall crack lengths are doubled to 0.32 inch and the crack center is located at the top of the blind zone. Thus, the crack spans both the blind zone and the inspectable region.
The postulated crack sizes and depths are two times the detectable limits with one-half (0.16 inch) of the flaw length being located in the examinable area.
This provides for a conservative evaluation because:
A)
By extending the postulated crack 0.16 inch into the inspectable region, it places the crack tip closer to the weld where the hoop stresses are higher; and B) it assumes that 0.16 inches of the inspectable region is already cracked, reducing the remaining area for crack propagation.
Throuqh-Wall Crack In addition to evaluating the part through-wall cracks, this evaluation also conservatively evaluates a through-wall axial crack. The through-wall axial crack is postulated to exist from the top of the blind zone down to a point where the hoop stress is < 10 ksi. This is a very conservative assumption, because for a crack to initiate on the surface and propagate through-wall while being totally contained within the blind zone would result in an unrealistic aspect ratio.
As can be concluded from the following analysis, the length of a part through-wall crack would propagate into the inspectable region long before its depth reaches a through-wall condition. However, evaluation of the through-wall crack provides completeness to this assessment and ensures all plausible crack propagation modes are considered. Like the part through-wall crack, the hoop stresses at the top of the blind zone were used as the initial stress with adjustments to account for the increased stresses as the crack approaches the weld.
The analyses include a finite element stress analysis of the CEDM nozzles and a fracture mechanics-based crack growth analysis for PWSCC. These analyses are
Engineering Report M-EP-2003-002 Rev. 01 Page 11 of 62 performed for four nozzles (the nozzles were chosen at four head angles 00, 8.80, 28.80, and 49.60) in the reactor vessel head to account for the varied geometry of the nozzle penetration. In this manner the analysis provides a bounding evaluation for all nozzles in the reactor vessel head. The sections that follow contain a description of the analyses, the results, and conclusions supported by the analyses.
2.0 Stress Analysis Finite element-based stress analyses for the ANO-2 CEDM penetrations, using the highest tensile yield strength for each group of nozzles, were performed using the best-estimate geometries based on previous UT and design information. The UT data obtained at the previous refueling outage were reviewed to determine the locations of the top and bottom of the J-weld at two azimuthal locations, downhill (0°) and the uphill (1800). The UT data obtained from this analysis is presented in Appendix A. This UT data were compared to the design information obtained from design drawings using an Excel spreadsheet to estimate the as-built condition. The spreadsheet used in this analysis is presented in Appendix A. This evaluation showed the following:
- 1) The central CEDM nozzles (00 and 8.80) have weld sizes that are similar in size to the design drawings. However, this analysis also showed that the nozzle length below the ID clad surface to be 2.08 inches (shorter by 0.4 inch) compared to the design length of 2.48 inches.
- 2) The downhill side fillet welds on the peripheral CEDM nozzles (28.80 and 49.60) have a longer leg than estimated from the design information. A fillet weld radius of 3/8 inch instead of the specified 3/16 inch provided the fillet weld leg length that matched the UT data. This evidence was also observed in another CE fabricated reactor vessel head. The fillet weld on the uphill side matched the information on the design drawing. Thus, only the downhill side fillet weld leg was extended for the model. The weld length on the uphill side matched the design information.
The evaluation to estimate the as-built dimensions of the CEDM configuration, taking into consideration the UT data and design information, consisted of the following steps:
- 1) The blind zone elevation of 1.544 inches from the nozzle bottom was taken to exist for all CEDM nozzles.
- 2) The design lengths for freespan at both the downhill and uphill locations were established (design length from weld bottom - blind zone).
- 3) These values were compared to the measurements obtained from the UT data analysis. The differences were recorded.
- 4) The design length to the top of the J-weld was compared to the measured length from the UT data for both the downhill and uphill locations and the differences recorded.
Engineering Report M-EP-2003-002 Rev. 01 Page 12 of 62
- 5) The weld lengths from design drawings were compared to the as measured data from the UT results. This was done for both the downhill and uphill locations. The differences were recorded.
- 6) The differences were evaluated to assess the variation between the design and as-measured data. This comparison showed that the differences for the central nozzles (8.80) were consistent but the differences at the uphill location was 0.53 inch and a downhill freespan location was about 0.33 inch. This variation could be reconciled if the nozzle was about 0.4 inch shorter than the design insertion length. Therefore, the design insertion length was reduced by 0.4 inch to minimize the variation between the as-measured and design data. The higher hillside angle nozzles (28.80 and 49.60) showed the variation to be more on the downhill side indicating a longer fillet weld leg length. This variation was minimized when the fillet weld radius was changed to 3/8 inch instead of the design specified value of 3/16 inch. Similar findings have been observed for another reactor vessel head fabricated by CE. Therefore, the increased fillet weld radius reasonably explains the larger fillet weld leg length observed in the UT data.
For these nozzles the fillet weld leg length was increased. Figure 3 presents the sketches for the higher hillside angle nozzles (28.80 and 49.60).
This geometry was used to develop the estimated as-built finite element model. For the central nozzle group (0° and 8.80), the nozzle insertion length was shortened by 0.4 inch to 2.08 inches. Since the weld lengths measured from the UT data matched the design data, the finite element model was developed using the shorter length but using the as-designed fillet weld dimensions.
R 3. 11 6I Fillet (A Designed)
(As Designedi
.44'
/ \\
.21'
\\
FEA~od~
=
FEA Model T
e I
\\
2.48-4 4 18" S P A 8 R 318 Fillet
____1______ - (Est. As Built)
_~~~~~~
p\\,o
\\i I\\\\
R 3/8" Fillet (Est. As Built) 28.80 Nozzle 49.6° Nozzle Figure 3: Estimated as-built nozzle configuration based on evaluation of the UT and design data. For the 49.6° nozzle, the bottom of the fillet weld extends 0.18 inch below the blind zone. For the 28.80 nozzle, the freespan length is reduced to 0.21 inch from the as-designed condition of 0.44 inch.
Cc'
Engineering Report M-EP-2003-002 Rev. 01 Page 13 of 62 The finite element modeling for obtaining the necessary stress (residual+operating) distribution for use in fracture mechanics analysis followed the process and methodology described in Reference 5a. The modeling steps were as follows:
- 1) The finite element mesh consisted of 3-dimensional solid (brick) elements.
Four elements were used to model the tube wall and similar refinement was carried to the attaching J-weld.
- 2)
The CEDM tube material was modeled with a monotonic stress strain curve.
The highest yield strength from the nozzle material bounded by the nozzle group was used. This yield strength was referenced to the room temperature yield strength of the stress-strain curve described in Reference 5a. The temperature dependent stress strain curves were obtained by indexing the temperature dependent drop of yield strength.
- 3)
The weld material was modeled as elastic-perfectly plastic for the weld simulation. This approximation is considered reasonable since most of the plastic strain in the weld metal occurs at high temperatures where metals do not work-harden significantly (Reference 5c). The temperature in the weld is always high during the welding process and once the weld begins to cool, the temperatures in the weld at which strain hardening would persist are of limited duration (Reference 5c). This was borne out by the comparison between the analysis based residual stress distribution and that obtained from experiments (Reference 5d).
- 4)
The weld is simulated by two passes based on studies presented in Reference 5a.
- 5) After completing the weld, a simulated hydro-test load step is applied to the model. The hydro-test step followed the fabrication practice.
- 6)
The model is then subjected to a normal operating schedule of normal heat up to steady state conditions at operating pressure. The residual plus operating stresses, once steady state has been achieved, are obtained for further analysis. The nodal stresses of interest are stored in an output file.
These stresses are then transferred to an Excel spreadsheet for use in fracture mechanics analysis.
The stress contours for the four nozzle groups obtained from the finite element analysis are presented in Figures 4 through 7. The stress contour color scheme are as follows:
Dark Navy blue fom Minimum (Compression) to -10 ksi Royal blue from -10 to 0 ksi Light blue from 0 to 0 ksi Light green from 10 to 20 ksi Green from 20 to 30 ksi Yellow green from 30 to 40 ksi Yellow from 40 to 50 ksi Red from 50 to 100 ksi
Full Cross-section Figure 4: Hoop stress contours for the 0° nozzle tube material. The bottom of the tube is in compi Engineering Report M-EP-2003-002 Rev. 01 Page 14 of 62 Zoomed in right weld High tensile stresses occur in the weld and adjacent ression.
Zoomed in Downhill side l/e. High tensile stresses occur in the weld and in compression.
Full cross-section Figure 5: Hoop stress contours for the 8. 8° nozz adjacent tube material. The bottom of the tube is
Engineering Report M-EP-2003-002 Rev. 01 Page 15 of 62 Full cross-section Zoomed in Downhill side Figure 6: Hoop stress contours for the 28.80 nozzle. High tensile stresses occur in the weld and adjacent tube material. The bottom of the tube is in compression.
Full cross-section Zoomed in Downhill side Figure 7: Hoop stress contours for the 49.6° nozzle. High tensile stresses occur in the weld and adjacent tube material. The bottom of the tube is in compression.
The nodal stresses for the locations of interest in each of the four nozzle groups were provided by Dominion Engineering Inc. and were tabulated in Reference C ( -05
Engineering Report M-EP-2003-002 Rev. 01 Page 16 of 62 5b. The nodal stresses and associated figures representing the OD and ID distributions along the tube axis are presented in tables and associated figures in the following pages. The location of the weld bottom was maintained at the node row ending with "601". The blind zone location is shown on the associated figure. For the nozzle group at 8.80, additional azimuthal locations (22.50, 450 and 67.50) around the circumference are shown. For the nozzle group at 28.80, an additional azimuthal location (22.50) around the circumference is shown. For the nozzle group at 49.60, additional azimuthal locations (22.50 and 450) around the circumference are shown.
These additional locations are shown since they were evaluated for establishing the augmented inspection scope. The zone of compressive stress is also marked in the figure.
From the tables and associated figures, a full visualization of the stress distribution in the nozzle, from the nozzle bottom (located at 0.0 inch) to the top of the J-weld is obtained. These figures are also shown in the Mathcad worksheets provided in the Appendix "C" attachments. The nodal stress distribution, provided by Dominion Engineering, is used to establish the region of interest and the associated stress distribution that will be utilized in the subsequent analyses. In all cases evaluated but one, the bottom end of the nozzle (free end) is observed to be in compression. This is expected since the tube in the vicinity of the weld is in tension (high hoop tension),
and the normal decay of stresses along the length of the tube results in compressive stress at the bottom. When the weld bottom extends lower, the compressive zone is shortened, but there remains a zone of compressive stress at the free end. For the 49.60 nozzle at the 90° rotated from the downhill location, the ID stress remains in tension while the OD stress becomes compressive (Figure 22)
In the following pages, the stress data from the Excel spreadsheet provided by Dominion Engineering (Reference 5b) and plots representing the axial distribution at the ID and OD locations are presented for each nozzle group with the specific azimuthal location that is evaluated. The location of the compression zone the blind zone and bottom of the weld are marked by colored reference lines.
Engineering Report M-EP-2003-002 Rev. 01 Page 17 of 62 Row 1
101 201 301 401 501
- 0. 000 0.485 0.874 1.186 1.436 1.635
-25.088
-0.56305 21.515 32.751 35.667 34.244
- 5%
-27.546
-0.53856 18.635 28.494 29.598 29.574
.7807 25%62 0-2 60
-27.787
-25.624
-23.763
-2.1108 17.122 24.136 26. 166 28.286
-4.851 14.843 19.645 25.589 35.408
-6.1565 10.089 14.45 28.417 45.379 701 801 901 1001 1101 1201 1301 1401
- 1. 932 2.068 2.204 2.341 2.477 2.613 2.750 2.886 23.674 18.928 16.541 17.561 22.026 26.382 30.043 33.132 26.502 24.564 22.854 22.683 23.229 25.611 28.69 31.073 33.261 33.968 34.789 33.806 32.421 31.17 33.688 37.166 47.609 49.071 49.525 47.49 44.118 41.606 38.959 43.676 64.65 65.876 62.795 63.558 58.478 52.552 45.295 36.261 Table 1: Nodal stress for 0° nozzle. This nozzle is symmetric about the nozzle axis hence these stresses prevail over the entire circumference. The weld location is shown by the shaded row.
Hoop Stress Plot
- o-ID Ho p Stress 60 l
OD H op Stress Top of Blie dZn 40 20 0
Top of Compressive Zone 00 0
Bottom of Weld
-20 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Distance from Nozzle Bottom {inch}
Figure 8: Plot showing hoop stress distribution along tube axis for the 0° nozzle. The top of compressive zone, the top of blind zone, and the bottom of the weld are shown.
C Q t*
Engineering Report M-EP-2003-002 Rev. 01 Page 18 of 62 R_
.eight..
1 0. 000 101 0.483 201 0.870 301 1.180 401 1.428 501 1.627 ID~
-27.404 0.63328 17.665 29.798 33.623 32.364
-24.356
-1.486 16.422
- 26. 049 27.792 28.469
-22.209
-3.5987 14. 61 22.723 24.8 27.591
-20.407
-4.4402 12.415 18.95 24.321 34.284
-18.978
-5.2679 9.3756 14.201
- 26. 989 45.104 701 1.919 21.498 25.556 33.55 801 2.051 16.944 23.793 34.064 901 2.183 14.834 22.263 34.779 1001 2.315 15.852 21.898 33.764 1101 2.448 20.835 22.531 32.095 1201 2.580 25.973 25.072 30.748 1301 2.712 29.955 28.372 32.593 1401 2.844 33.46 31.26 36.351 Table 2: Nodal stress for 8.80 nozzle at the downhill location.
shaded row.
Hoop Stress Ph
-o--
ID Ho p Stress 60 H op Stress Top of 8firdZone
-40 2 20 To, of Co.. ~ s~
Zo.
0
-20 48.089 66.365 49.472 67.672 49.055 63.377 46.61 61.537 42.501 53.972 39.365 47.486 36.879 39.934 41.573 31.302 The weld location is shown by the lo t 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Distance from Nozzle Bottom {inch}
Figure 9: Plot showing hoop stress distribution along tube axis for the 8.8° nozzle at the downhill location. The top of compressive zone, the top of blind zone, and the bottom of the weld are shown.
cos-
Engineering Report M-EP-2003-002 Rev. 01 Page 19 of 62 Row 10001 10101 10201 10301 10401 10501 0
0.48843 0.87972 1.1932 1.4443 1.6455
-27.118 0.64978 17.955 29.829 33.679 32.389
-24.146
-1.526 16.435 26.102 27.823 28.385
-22.087
-3.6985 14.447 22.672 24.722 27.447 75%
-20.358
-4.5989 12.118 18.714 24.104 34.121
-18.981
-5.4683 8.9948 13.833 26.541 44.818 10701 1.9403 21.477 25.458 33.3 47.738 65.934 10801 2.074 16.919 23.701 33.846 49.217 67.244 10901 2.2076 14.769 22.095 34.557 48.869 62.964 11001 2.3413 15.756 21.725 33.561 46.369 61.153 11101 2.4749 20.717 22.317 31.908 42.308 53.889 11201 2.6085 25.789 24.923 30.579 39.284 47.365 11301 2.7422 29.737 28.248 32.847 37.236 40.412 11401 2.8758 33.001 30.843 35.887 41.552 34.5 Table 3: Nodal stress for 8.80 nozzle at 22.5° rotated from the downhill location.
shown by the shaded row.
The weld location is Hoop Stress Plot 60 40 CA n(
e! 20 0.
o W
0
-20
-40 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Distance from Nozzle Bottom {inch}
Figure 10: Plot showing hoop stress distribution along tube axis for the 8.80 nozzle at 22.50 rotated from the downhill location. The top of compressive zone, the top of blind zone, and the bottom of the weld are shown.
CQcc
Engineering Report M-EP-2003-002 Rev. 01 Page 20 of 62 20001 20101 20201 20301 20401 20501 AHeightA 0
0.50592 0.91123 1.2359 1.4961 1.7045 AID ;~5'.
-26.311
-0.3769 20.089 29.934 33.829 32.487 OW,
-23.544
-2.2224 16.851 26.239 27.906 28.206
-21.718
-3.9683 14.017 22.486 24.526 27.053 NO l
-20.18
-5.0362 11.337 18.067 23.554 33.58
-D
-18.943
-6.0278 7.9165 12.788 25.421 44.169
I 20701 20801 20901 21001 21101 21201 21301 21401 2.0063 2.1413 2.2762 2.4111 2.5461 2.681 2.8159 2.9509 21.433 16.793 14.561 15.505 20.329 25.223 29.209 32.564 25.168 23.322 21.627 21.303
- 21. 914 24.532 27.786 30.324 32.645 33.237 33. 983 33.027 31.51 30.274 32.709 35.521 46.971 48.59 48.342 45.936 42.056 39.283 37.408 41.82 64.949 66.19 62.067 60.887 54.174 47.704 41.335 35.243 Table 4: Nodal stress for 8.80 nozzle at 450 rotated from the downhill location.
shown by the shaded row.
The weld location is Hoop Stress Plot 60 40 e 20 0.
0 0d I
0
-20
-40 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Distance from Nozzle Bottom {inch}
Figure 11: Plot showing hoop stress distribution along tube axis for the 8. 8° nozzle at 450 rotated from the downhill location. The top of compressive zone, the top of blind zone, and the bottom of the weld are shown.
Ca7
Engineering Report M-EP-2003-002 Rev. 01 Page 21 of 62 R ow 30001 30101 30201 30301 30401 30501 0
0.53254 0.95918 1.301 1.5748 1.7941 i : ID
-25.236
- 1.2673 21.942 30.023 34.094 32.716 25%
-22.713
-2.9633 17.089 26.373 28.085 28.035 50%
-21.175
-4.403 13.361 22.21 24.306 26.605
-19.868
-5.6895 10.182 17.121 22.834 32. 916
-18.802
-6.8335 6.3275 11.241 23.834 43.289 30701 2.1061 21.457 24.92 31.944 46.103 63.871 30801 2.2422 16.731 22.988 32.591 47.9 65.049 30901 2.3784 14.342 21.261 33.406 47.848 61.204 31001 2.5145 15.204 20.994 32.436 45.675 60.976 31101 2.6507 19.799 21.653 30.997 42.11 55.015 31201 2.7869 24.558 24.206 29.798 39.607 48.995 31301 2.923 28.72 27.503 32.15 37.459 42.682 31401 3.0592 32.844 30.245 35.773 41.844 36.257 Table 5: Nodal stress for 8.80 nozzle at 67.50 rotated from the downhill location.
shown by the shaded row.
The weld location is Hoop Stress Plot 60 40 W
01 20 n
0 I
0
-20
-40 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Distance from Nozzle Bottom {inch}
Figure 12: Plot showing hoop stress distribution along tube axis for the 8.8° nozzle at 67.50 rotated from the downhill location. The top of compressive zone, the top of blind zone, and the bottom of the weld are shown.
Engineering Report M-EP-2003-002 Rev. 01 Page 22 of 62 Row 40001 40101 40201 40301 40401 40501 0.000 0.564 1.016 1.378 1.668 1.900 AD 0
M-%
-24.18
-21.838
-20.55
-19.438
-1.4119
-3.3196
-4.9822
-6.4762 22.032 16.773 12.529 8.7215 29.956 26.483 21.849 16.053 34.51 28.439 24.198 22.09 33.218 28.069 26.319 32.416
,O.
- 18.504
-7.7535 4.4282 9.4283 22.082 42.48 40701 40801 40901 41001 41101 41201 41301 41401 2.224 2.361 2.499 2.636 2.773 2.911 3.048 3.185 22.006 17.219 14.675 15.505 19.832 24.356 28.385 31.93 25.059 23.064 21.28 21.064 21.649 24.044 27.206 29.733 31.606 32.349 33.218 32.273 31.008 29.89 32.287 35.809 45.624 63.118 47.567 64.115 47.796 60.65 45.911 61.401 42.649 56.171 40.44 50.554 37.721 43.702 42.479 38.37 from the downhill location.
Table 6: Nodal stress for 8.8° nozzle at (Mid-Plane) 90° rotated location is shown by the shaded row.
The weld Hoop Stress Plot 60 40 02 4)0 20 0
0
=
0
-20
-40 0.0 0.5 1.0 1.5 2.0 Distance from Nozzle Bottom {inch}
2.5 3.0 3.5 Figure 13: Plot showing hoop stress distribution along tube axis for the 8.8° nozzle at (Mid-Plane) 90° rotated from the downhill location. The top of compressive zone, the top of blind zone, and the bottom of the weld are shown.
Engineering Report M-EP-2003-002 Rev. 01 Page 23 of 62 80001 80101 80201 80301 80401 80501 0.000 0.645
- 1. 162 1.576
- 1. 907 2.173 Hi
-22.34
-0.72174 17.28 29.359 36.503 36.536
-20.022
-3.6673 14.912 26.501 30.924 30.331 NW"
-18.961
-6.8206 9.6529 20.582 25.411 27.24 i'WS
-18.087
-8.6957 3.7661 13.796 21.15 32.606 OD jW 0,..
-17.153
-10.19
-1.2205 4.7531 18.374 41.485 80701 80801 80901 81001 81101 81201 81301 81401 2.528 2.670 2.813 2.955 3.098 3.240 3.382 3.525 27.116 21.957 18.993 19.578 23.12 26.499 29.872 32.509 28.37 26.115 24.124 24.12 24.375 26.538 29.202 30.842 at (Uphill) 33.434 34.408 35.202 34.376 33.301 32.257 35.086 37.607 47.233 48.851 49.904 48.405 45.647 43.763 41.634 45.45 63. 826 63.884 62.107 64.458 61.604 56.525 49.89 40.77 Table 7: Nodal stress for 8.80 nozzle location is shown by the shaded row.
60 ID Hoo Stres OD Ho p Stre 40 -
Top o 0 20 Top of Compression Zone O
0 0/0 0
-20
-40 1800 rotated from the downhill location. The weld Hoop Stress Plot 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Distance from Nozzle Bottom {inch)
Figure 14: Plot showing hoop stress distribution along tube axis for the 8. 8° nozzle at (Uphill) 1800 rotated from the downhill location. The top of compressive zone, the top of blind zone, and the bottom of the weld are shown.
Engineering Report M-EP-2003-002 Rev. 01 Page 24 of 62 1
0.000 101 0.461 201 0.830 301 1.126 401 1.363 501 1.552 i, I,,H,M,
- 17.414
-8.4943 0.088906 7.0251 8.2154 13.266 A
}
M z
-13.552
-6.31 0.17947 6.9534 10.954 16.41 50$
-11.113
-4.924 0.11003 6.3144 10.85 16.061
-8.8843
-3.7058 0.18625 5.2078 9.5121 17.131 PDo
-6.6283
-2.5412 0.2839 4.6462 5.6465 25.256 701 801 901 1001 1101 1201 1301 1401 1501 1601 1701 1801 1.825 1.946 2.066 2.187 2.308 2.428 2.549 2.670 2.790 2.911 3.032 3.152
- 29. 036 33.945
- 29. 591 23.26 18.689 15.391 14.546
- 16. 833
- 22. 94 30.347 36.319 40.587 28.83 30.929 31.788 29.738 27.734 26.097 24.118 23.402 24.557 28.824 33.178 36.14 31.285 36.407 40.536 41.2 41.29 40.668 39.369 37.135 33.686 34.637 37.13 41.105 53.547 61.6 64.612 64.193 61.777 58.596 54. 107 47.479 39.867 35.903 37.761 36.249 64.082 71.01 76.418 79.626 78.117 72.784 62.074 45.328 31.733 24.215 22.663
-4.0021 Table 8: Nodal stress for 28.8° nozzle at downhill location. The weld location is shown by the shaded row.
Hoop Stress Plot 80 -
ID Hoop Stress OD Hoop St 60 Top of Blind Zor a 40
~- 40
~
0
//A Top of Compression Zone 8 20
-0
_Bottom of Weld
-20 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Distance from Nozzle Bottom {inch}
Figure 15: Plot showing hoop stress distribution along tube axis for the 28.80 nozzle at downhill location. The top of compressive zone, the top of blind zone, and the bottom of the weld are shown.
C'!
Engineering Report M-EP-2003-002 Rev. 01 Page 25 of 62 10001 10101 10201 103 01 10401 10501 0
0.49517 0.89187 1.2097 1.4643 1.6682
-14.205
-6.4931 1.5545 8.4295 10.247 15.665
-11.506
-5.1879 1.0213 7.9804 12.709 18.335
-9. 7904
-4.4249 0.5647 7.1986 12.22 18.703
-8.2433
-3.7959
- 0. 2 5683 6.1861 11.35 20.835
-6.7219
-3.1762
-0.0759 5.292 8.3641 29.697 10701 10801 10901 11001 11101 11201 11301 11401 11501 11601 11701 11801 1.9511 2.0706 2.1901 2.3096 2.4291 2.5486 2.6681 2.7876 2.9071 3.0266 3.1461 3.2656 31.496 31.975 26.833 20.84 15.99 12.461 11.21 13.526 19.78 26.712 32.478 36.911 28.696
- 30. 109 29.946
- 27. 2 87 24.671 22.874 20.931
- 20. 476 22.135 26.192 30.015 32.504 31.228 35.633 38.369 38.5 38.159 37.588 36.521 34.299 31.566 32.945 35.497 38.269 53.015 59.449 61.124 59.952 58.169 54.954 51.142 45.784 38.968 36.476 38.328 35.608 63.555 69.026 72.691 75.043 73.854 67.711 59.155 43.711 31.028 24.484 23.185 2.1982 Table 9: Nodal stress for 28.8° nozzle at 22.50 rotated from the downhill location. The weld location is shown by the shaded row.
Hoop Stress Plot 80 ID Hoop Stres l
^
OD Hoop Stre LI 60 Top of Btin Zone 4
40 2
20 0
-2 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Distance from Nozzle Bottom {inch)
Figure 16: Plot showing hoop stress distribution along tube axis for the 28.8nozzle at 22.5"rotated from the downhill location. The top of compressive zone, the top of blind zone, and the bottom of the weld are shown.
CL\\b-.
Engineering Report M-EP-2003-002 Rev. 01 Page 26 of 62 Aow 4000 1 40101 40201 40301 40401 40501 Heig4htf 0
.000 0.811 1.460
- 1. 980 2.397 2.731 2.0791 0.091 5.2826 16.881 24.144 26.962
-0.87476
-2.3704 1.6859 12.419 20.894 22.672
-2.9601
-4.267
-0.78573 9.564 18.115 20.686 75%
-4.82
-6.0042
-2.4896 6.9075 16.59 24.842 00'd
-6.7498
-7.5523
- 3.4686 4.3191 14.513 33.523 Ml 40701 40801 40901 41001 41101 41201 41301 41401 41501 41601 41701 41801 3.113 3.228 3.343 3.457 3.572 3.687 3.801 3.916 4.031 4.145 4.260 4.375 17.161 11.722 6.0041 1.439
-2.1749
-4.7249
-4.9201
-2.8845 0.86049 5.584 9.8086 17.392 17.101 14.424 11.108 8.0852 5.8905 4.8584 4.8793 6.4727 8.0075 11.001 14.62 18.195 20.743 21.34 20.912 20.38 19.929 19.994 20.34 20.545 21.386 22.915 25.477 28.176 41.091 43.543 43.833 43.021 42.405 40.425 38.451 37.523 36.18 36.59 36. 977 40.112 51.762 53.688 54.154 57.025 56.415
- 58. 85 57.617 49.152 40.228 35.152 32.699 19.759 Table 10: Nodal stress for 28.8° nozzle at (Mid-Plane) 90 rotated from the downhill location. The weld location is shown by the shaded row.
Hoop Stress Plot
-o---
ID Ho p Stress OD Ho p Stress 5 0 Top of Blind Z ne
- 0) U, 30 o
Top of Compression Zone 0x 1 0
-1 0
~~~~~~~~~~~~~~~~~~~~Bottom of Weld 0
1 2
3 4
Distance from Nozzle Bottom {inch)
Figure 17: Plot showing hoop stress distribution along tube axis for the 28.80 nozzle at (Mid-Plane) 900 rotated from the downhill location. The top of compressive zone, the top of blind zone, and the bottom of the weld are shown.
Engineering Report M-EP-2003-002 Rev. 01 Page 27 of 62 e i 80001 80101 80201 80301 80401 80501 Height 0.000 1.154 2.078 2.819 3.412 3.888
-9.0335
- 6.761 7.9654 23.851 43.99 47.954
-5.8552
-6.7389 1.7419 21.763 38.072 41.753
-4.2456
-7.2366
-6.2304 8.5552 29.826 35.453
-2.6894
-7.6623
-11.848
-6.3899 13.47 33.324 OD
-1.0312
-7.8035
- 16.387
-17.647
-1.6316 35.846 80701 4.377 40.773 36.237 41.27 61.453 62.189 80801 4.486 39.277 35.327 44.863 64.204 63.895 80901 4.595 36.022 35.389 46.842 64.323 62.934 81001 4.704 33.54 36.173 48.06 64.483 66.03 81101 4.813 32.631 36.616 47.779 67.612 70.356 81201 4.922 32.794 36.656 47.356 66.386 72.973 81301 5.031 33.889 36.612 47.548 65.375 77.806 81401 5.140 35.222 36.179 47.538 65.411 75.322 81501 5.249 36.353 35.865 47.964 64.448 70.447 81601 5.358 36.426 36.986 48.341 62.979 62.511 81701 5.467 37.233 38.52 49.064 63.153 61.112 81801 5.575 40.874 39.218 48.17 62.039 57.291 Table 11: Nodal stress for 28.80 nozzle at (Uphill) 1800 rotated from the downhill location. The weld location is shown by the shaded row.
Hoop Stress Plot 80 Not. :- Top of Compressin Zone
-o----
ID Hoop Stre s 81id Zoeo noide-t OD Hoop Stre SS]
60 4
40 Top of Compresslo one rE~~~~~~Top of Blind Zone o f SD 00 8 20 Bottom of Weld 0
-2 0 0
1 2
3 4
5 6
Distance from Nozzle Bottom {inch)
Figure 18: Plot showing hoop stress distribution along tube axis for the 28.80 nozzle at (Uphill) 180° rotated from the downhill location. The top of compressive zone, the top of blind zone, and the bottom of the weld are shown.
C LL