ML15022A662
| ML15022A662 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 05/31/2014 |
| From: | Teske M Continuum Dynamics |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML15023A070 | List: |
| References | |
| NMP2L 2566 14-09NP | |
| Download: ML15022A662 (73) | |
Text
ATTACHMENT 3 NONPROPRIETARY VERSION OF CDI REPORT NO.14-09P
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information C.D.I. Report No. 14-09NP Acoustic and Low Frequency Hydrodynamic Loads at 115% CLTP Target Power Level on Nine Mile Point Unit 2 Steam Dryer to 250 Hz Using ACM Rev. 4.1R Revision 1 Prepared by Continuum Dynamics, Inc.
34 Lexington Avenue Ewing, NJ 08618 Prepared under Purchase Order No. 7736902 for Constellation Energy Nine Mile Point Nuclear Station, LLC.
P.O. Box 63 Lycoming, NY 13093 Prepared by Milton E. Teske Approved by m
(cAA-s-14 f
Alan J. Bilani n May 2014
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Executive Summary Measured strain gage time-history data in the four main steam lines at Nine Mile Point Unit 2 (NMP2), taken during power ascension from Current Licensed Thermal Power (CLTP) to Extended Power Uprate (EPU) power levels, were processed by a dynamic model of the steam delivery system to predict loads on the full-scale steam dryer. These loads were processed by a real-time stress analysis to predict the minimum stress ratio at each examined power level and enable the drawing of limit curves that assisted in the ascension to EPU conditions. This report summarizes the loads at 115% CLTP target power conditions.
At each power level the measured data were first converted to pressures, then positioned on the four main steam lines and used to extract acoustic sources in the system. A validated acoustic circuit methodology, ACM Rev. 4.1 (rebenchmarked as Rev 4. IR), was used to predict the fluctuating pressures anticipated across components of the steam dryer in the reactor vessel.
The acoustic circuit methodology included a low frequency hydrodynamic contribution, in addition to an acoustic contribution at all frequencies. This pressure loading was then provided for structural analysis to assess the structural adequacy of the steam dryer in NMP2.
This effort provides the Constellation Energy Group with a dryer dynamic load definition that comes directly from measured NMP2 full-scale data and the application of a validated acoustic circuit methodology, at every power level where data were acquired.
i
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Table of Contents Section Page Executive Summary .................................................................. i T able of C ontents ..................................................................... ii
- 1. Introduction ............................................................................ 1
- 2. Modeling Considerations ............................................................ 2 2.1 Helmholtz Analysis ........................................................... 2 2.2 Acoustic Circuit Analysis .................................................... 3 2.3 Low Frequency Contribution ................................................ 4 2.4 ACM Rev. 4.1R ............................................................... 5
- 3. Input Pressure D ata ................................................................... 6 4 . R esu lts ................................................................................. 18
- 5. Uncertainty Analysis .............................................................. 25
- 6. C onclusions ........................................................................... 27
- 7. References ............................................................................. 28 Appendix A: Power Ascension Data Comparison .............................. 30 Appendix B: Acoustic Circuit Model Rev. 4.1R ................................ 45 Appendix C: Comparison Between Rev. 4.1 and Rev. 4.1R ................... 56 Appendix D: MSL A Upper Strain Gage Signals ............................... 68 ii
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
- 1. Introduction In Spring 2005 Exelon installed new steam dryers into Quad Cities Unit 2 (QC2) and Quad Cities Unit 1. This replacement design, developed by General Electric, sought to improve dryer performance and overcome structural inadequacies identified on the original dryers, which had been in place for 30 years. As a means of confirming the adequacy of the steam dryer, the QC2 replacement dryer was instrumented with pressure sensors at 27 locations. These pressures formed the set of data used to validate the predictions of an acoustic circuit methodology under development by Continuum Dynamics, Inc. (C.D.I.) for several years [1]. One of the results of this benchmark exercise [2] confirmed the predictive ability of the acoustic circuit methodology for pressure loading across the dryer, with the inclusion of a low frequency hydrodynamic load.
This approach, validated against the Exelon full-scale data and identified as the Acoustic Circuit Model (ACM) Rev. 4.1 [3], and rebenchmarked as Rev. 4.1R, is used in the effort discussed herein.
ACM Rev. 4.1R filters the QC2 data in exactly the same way as the Nine Mile Point Unit 2 (NMP2) data, that is, (1) the EMF frequencies of 60, 120, 180, and 240 Hz are filtered; (2) the vane passing frequency and other non-acoustic frequencies identified in the EIC data are also filtered; and (3) the strain gage signals at the upper and lower locations on each main steam line are coherence filtered. The resulting loads are computed for the Nine Mile Point dryer, after applying bias and uncertainty values found when comparing model predictions on the QC2 dryer with pressure data recorded on the outer bank hoods of the QC2 dryer.
This report applies this validated methodology to the NMP2 steam dryer and main steam line geometry. Strain gage data obtained from the four main steam lines were used to predict pressure levels on the NMP2 full-scale dryer at 115% CLTP target power conditions. These data were then used to predict dryer stresses, and to determine the minimum stress ratio on the dryer.
The intermediate results from Current Licensed Thermal Power (CLTP) to 115% CLTP target power conditions were used to develop limit curves.
Plots of all applicable data are summarized in Appendix A of this report.
1
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
- 2. Modeling Considerations The acoustic circuit analysis of the NMP2 steam supply system is broken into two distinct analyses: a Helmholtz solution within the steam dome and an acoustic circuit analysis in the main steam lines. This section of the report highlights the two approaches taken here. These analyses are then coupled for an integrated solution.
2.1 Helmholtz Analysis A cross-section of the steam dome (and steam dryer) is shown below in Figure 2.1, with NMP2 dimensions as shown [4]. The complex three-dimensional geometry is rendered onto a uniformly-spaced rectangular grid (with mesh spacing of 1.5 inches to accommodate frequencies from 0 to 250 Hz in full scale), and a solution, over the frequency range of interest, is obtained for the Helmholtz equation a 2P a2 pP 2p (2p 2 2P,2P=O
+ 7 a PV a+
R a' a b -, .a W b'
I4I * - -
A I
e f I g k
Figure 2.1. Cross-sectional description of the steam dome and dryer at NMP2, with the dimensions ofa = 18.25 in, a' = 15.25 in, b = 13.27 in, b' = 13.65 in, c = 15.75 in, c' = 24.0 in, d = 15.75 in, e = 16.25 in, f= 71.5 in, g = 160.625 in, i = 84.5 in,j =
181.5 in, k= 118.75 in, andR= 124.75 in.
2
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information where P is the pressure at a grid point, co is frequency, and a is complex acoustic speed in steam.
This equation is solved for incremental frequencies from 0 to 250 Hz, subject to the boundary conditions dP
-=0 dn normal to all solid surfaces (the steam dome wall and interior and exterior surfaces of the dryer),
dP io) p dn a normal to the nominal water level surface, and unit pressure applied to one inlet to a main steam line and zero applied to the other three.
For the present effort the Helmholtz solutions were revisited using an algorithm that converged more rapidly and to lower error than previous solutions.
2.2 Acoustic Circuit Analysis The Helmholtz solution within the steam dome is coupled to an acoustic circuit solution in the main steam lines. Pulsation in a single-phase compressible medium, where acoustic wavelengths are long compared to transverse dimensions (directions perpendicular to the primary flow directions), lend themselves to application of the acoustic circuit methodology. If the analysis is restricted to frequencies below 250 Hz, acoustic wavelengths are approximately six feet in length and wavelengths are therefore long compared to most components of interest, such as branch junctions.
Acoustic circuit analysis divides the main steam lines into elements which are each characterized, as sketched in Figure 2.2, by a length L, a cross-sectional area A, a fluid mean density p, a fluid mean flow velocity U, and a fluid mean acoustic speed a.
- A - element cross-sectional area U,F,a (D) )
L Figure 2.2. Schematic of an element in the acoustic circuit analysis, with length L and cross-sectional area A.
3
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Application of acoustic circuit methodology generates solutions for the fluctuating pressure Pn and velocity un in the nth element of the form Pn = [AneiknXn +Bneik2nXn Jeiwt
_ p2 [(J + Unkn )AneiklnXn + ((0 + Unk2n )Bneik2nXn jeiWt U
where harmonic time dependence of the form eiOt has been assumed. The wave numbers kin and k2n are the two complex roots of the equation 2
kn + -2 ;(o+ nkn)-_-(cO+UnknY =0 Dna a where fn is the pipe friction factor for element n, Dn is the hydrodynamic diameter for element n, and i = V--iT. An and Bn are complex constants which are a function of frequency and are determined by satisfying continuity of pressure and mass conservation at element junctions.
The solution for pressure and velocity in the main steam lines is coupled to the Helmholtz solution in the steam dome, to predict the pressure loading on the steam dryer.
The main steam line piping geometry is summarized in Table 2.1.
Table 2.1. Main steam line lengths at NMP2, measured from the inside wall of the steam dome down the centerline of the main steam lines. Main steam line diameter is 26 inch Schedule 80 (ID = 23.50 in).
Main Steam Line Length to First Length to Second Strain Gage Strain Gage Measurement (ft) Measurement (ft)
A 13.6 26.2 B 14.5 19.9 C 22.1 27.5 D 20.4 25.8 2.3 Low Frequency Contribution (3)))
4
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information 2.4 ACM Rev. 4.1R (3)))
5
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
- 3. Input Pressure Data Strain gages were mounted on the four main steam lines of NMP2. Two data sets were examined in the analysis. The first data set recorded the strain at Low Power (25% CLTP target power), while the second data set recorded the strain at 115% CLTP target power. The data analyzed in this report were provided in the following files:
Data File Name Target Power Level(% CLTP) 20120609134630 25%
20120721142636 115%
The strain gage signals were converted to pressures by the use of the conversion factors provided in [5] and summarized in Table 3.1. The raw data signals are shown in Figure 3.1.
Exclusion frequencies were used to remove extraneous signals, as also identified in [5],
summarized in Table 3.2 and shown in Figure 3.2. These signals were further processed by coherence filtering as described in [3]. The upper strain gage signal contribution on MSL A is described in Appendix D.
All pressure signals result from either hydrodynamic fluctuations or random noise. To be conservative, these signals will be assumed to have a load that is hydrodynamic in nature.
Therefore, a load is imposed on the dryer at all frequencies, and the bias and uncertainty are determined by benchmarking against QC2 data, as described in [3].
The coherence filtered main steam line pressure signals may be represented in two ways, by their minimum and maximum pressure levels, and by their PSDs. Table 3.3 provides the pressure level information, while Figure 3.3 compares the frequency content at the eight strain gage locations. Figure 3.4 compares the raw data signals to the final rebenchmarked signals used in ACM Rev. 4.1R.
NMP2 testing determined that the MSL B loads were affected by the RCIC steam line configuration. Further testing and analyses were undertaken at the 115% CLTP target power level to define the loads for the RCIC steam line isolated configuration (with 89.3 Hz content) and the RCIC drain trap out-of-service configuration (with 92.5 Hz content). The RCIC steam line isolated configuration is considered off-normal and associated with a short-duration technical specification limiting condition-of-operation duration. Cycle counting is used to analyze this configuration [7]. The RCIC drain trap out-of-service configuration now occurs more frequently and may become normal operation. The final stress report [6] addresses these loading conditions and the impact of the additional RCIC conditions on the locations of maximum stress on the dryer.
6
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Table 3.1. Conversion factors from strain to pressure at 115% CLTP target power conditions
[5]. Channels are averaged to give the average strain.
Location Strain to Channel Channel Channel Channel Pressure Number Number Number Number (psid/jtstrain)
MSL A Upper 3.82 1 2 3 4 MSL A Lower 3.84 5 6 7 8 MSL B Upper 3.84 9 10 11 12 MSL B Lower 3.81 13 14 15 16 MSL C Upper 3.85 17 18 19 20 MSL C Lower 3.81 21 22 23 24 MSL D Upper 3.92 25 26 27 28 MSL D Lower 3.94 29 30 31 32 Table 3.2. Exclusion frequencies for NMP2 strain gage data at 115% CLTP target power conditions, as suggested in [5]. The frequency range is applied with a second-order, stop-band Butterworth filter in MatLab.
Frequency Range (Hz) Exclusion Cause 0.0 - 2.0 Mean 59.9-60.1 EMF Frequency 119.6 - 120.3 EMF Frequency 179.8 - 180.2 EMF Frequency 148.9 - 149.3 Recirculation Vane Passing Frequency Table 3.3. Main steam line (MSL) pressure levels in NMP2 at 115% CLTP target power conditions, after coherence filtering.
Minimum Maximum RMS Pressure (psid) Pressure (psid) Pressure (psid)
MSL A Upper -2.59 2.37 0.56 MSL A Lower -2.32 2.36 0.54 MSL B Upper -1.97 1.48 0.40 MSL B Lower -1.30 1.31 0.34 MSL C Upper -2.09 1.62 0.42 MSL C Lower -3.17 2.54 0.63 MSL D Upper -2.07 2.00 0.49 MSL D Lower -1.56 1.72 0.35 7
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information NMP2: Unfiltered Data 0.1 I-MSL A Upper N 0.01 - .................. ............--- M SL A Lower -----
0Z 0.001 C/)
0.0001 --------------- --- --- --- -- -
10-5 0 50 100 150 200 250 Frequency (Hz)
NMP2: Unfiltered Data 0.1 MSL B Upper N 0.01 ......-- MSL B Lower -----
0.001 . . . . . . . . . .. . . .- .- . - . .- . - . .- .-. .- .- .- . . .. .
0.0001 10-5 0 50 100 150 200 250 Frequency (Hz)
Figure 3.1 a: Unfiltered data measured on the NMP2 main steam lines at 115% CLTP target power conditions for main steam lines A (top) and B (bottom).
8
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information NMP2: Unfiltered Data 0.1 N 0.01 0.001 0.0001 10-5 0 100 150 250 Frequency (Hz)
NMP2: Unfiltered Data 0.1 N 0.01 IE 0.001 0.0001 10-5 0 100 150 250 Frequency (Hz)
Figure 3.1b: Unfiltered data measured on the NMP2 main steam lines at 115% CLTP target power conditions for main steam lines C (top) and D (bottom).
9
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information NMP2: Exclusion Filtered Data 0.1 MSL A Upper N 0.01 MSL A Lower i A Cl "C
0.001 ----------------- :- - - - - - - -- - - - - - - -
C/)
0.0001 -.--------------- I-10-5 0 50 100 150 200 250 Frequency (Hz)
NMP2: Exclusion Filtered Data 0.1 MSL B Upper
____ fl. I ni~r
'-N N 0.01 Cl "0
0.001
-~~~
~ ~ -------------------- ------------ M TRIe 0.0001 10-5 0 50 100 150 200 250 Frequency (Hz)
Figure 3.2a: Exclusion filtered data measured on the NMP2 main steam lines at 115% CLTP target power conditions for main steam lines A (top) and B (bottom).
10
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information NMP2: Exclusion Filtered Data 0.1 MSL C Upper N 0.01 MSL C Lower -----
A A -- - - - ,-
0.001 0.0001 -- - -- - -- -
10-5 0 50 100 150 200 250 Frequency (Hz)
NMP2: Exclusion Filtered Data 0.1 MSL D Jpper N 0.01 ...............--- MSL D Lower
-d 0.001 0.0001 105 0 50 100 150 200 250 Frequency (Hz)
Figure 3.2b: Exclusion filtered data measured on the NMP2 main steam lines at 115% CLTP target power conditions for main steam lines C (top) and D (bottom).
11
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)))
Figure 3.3a: Coherence filtered data measured on the NMP2 main steam lines at 115% CLTP target power conditions for main steam lines A (top) and B (bottom).
12
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)))
Figure 3.3b: Coherence filtered data measured on the NMP2 main steam lines at 115% CLTP target power conditions for main steam lines C (top) and D (bottom)..
13
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)))
Figure 3.4a: Unfiltered and filtered data comparisons on NMP2 main steam line A at 115%
CLTP target power conditions for upper (top) and lower (bottom) locations.
14
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)]
Figure 3.4b: Unfiltered and filtered data comparisons on NMP2 main steam line B at 115%
CLTP target power conditions for upper (top) and lower (bottom) locations.
15
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
((
(3)))
Figure 3.4c: Unfiltered and filtered data comparisons on NMP2 main steam line C at 115%
CLTP target power conditions for upper (top) and lower (bottom) locations.
16
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)))1 Figure 3.4d: Unfiltered and filtered data comparisons on NMP2 main steam line D at 115%
CLTP target power conditions for upper (top) and lower (bottom) locations.
17
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
- 4. Results Measured main steam line pressure data were used to drive the validated ACM Ref. 4.1 R methodology for the NMP2 steam dome coupled to the main steam lines to make a pressure load prediction on the NMP2 dryer at 115% CLTP target power conditions. Two sets of results are obtained:
- 1. A low resolution load, developed at the nodal locations identified in Figures 4.1 to 4.4, produces the maximum differential pressure RMS pressure levels across the dryer as shown in Figure 4.5. PSDs of the peak loads on either side of the dryer are shown in Figure 4.6.
- 2. The four main steam line entrance pressures (in front of MSL A, B, C, and D) are transferred to the ANSYS analysis for the computation of dryer stresses. The impact of these loads is found by first developing the Helmholtz unit monopole solution for unit pressure in front of the main steam line (as described in Section 2.1), and a corresponding unit dipole solution. As a consequence of improving the accuracy of the Helmholtz predictions, as noted in Section 2.1, transfer of the unit solutions was generalized to include all possible pressure differences across the NMP2 dryer. This generalization enhances the load definition provided to ANSYS but does not change the ACM Rev. 4.1R rebenchmark analysis.
These loads include the conservative bias and uncertainty corrections discussed in Section 5 of this report.
18
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Figure 4.1. Cover and base plate low resolution load pressure node locations on the NMP2 dryer, with pressures acting downward in the notation defined here. MSL A is off the upper right comer of the figure; MSL B is off the lower right comer of the figure; MSL C is off the lower left comer of the figure; and MSL D is off the upper left comer of the figure. The cover plate on the A/B side of the dryer is identified by the nodes 98-99-100-105; the cover plate on the C/D side of the dryer is identified by the nodes 3-8-7-6. Base plates are identified by the nodes 64-65-66-77-76-75 and 82-83-84-95-94-93 (A/B side), 48-49-50-59-58-57 (center), and 12-13-14-24-23-22 and 30-31-32-42-41-40 (C/D side). The grid mesh (for the Helmholtz analysis) is spaced 1.5 inches everywhere on the dryer.
19
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information 10
", 10 16 21---2.. 4 55 ~q 3J L+/-.6 [ ------- 5,' - - -881 91 27 90 87 72
'-- 1 ..... _5 4515
, 69 Figure 4.2. Top plate low resolution load pressure node locations on the NMP2 dryer, with pressures acting downward in the notation defined here. MSL A is off the upper right comer of the figure; MSL B is off the lower right comer of the figure; MSL C is off the lower left comer of the figure; and MSL D is off the upper left comer of the figure. Top plates on the A/B side of the dryer are identified by the nodes 90 92-103-102-101, 72-73-74-89-88-87, and 54-55-56-71-70-69. Top plates on the C/D side of the dryer are identified by the nodes 9-10-11-17-16-15, 27-28-29-35-34-33, and 45-46-47-53-52-51. The grid mesh (for the Helmholtz analysis) is spaced 1.5 inches everywhere on the dryer.
20
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information S
Figure 4.3. Outer and inner hood low resolution load pressure nodes on the NMP2 dryer. MSL A and MSL B are off the upper right comer of the figure; MSL C and MSL D are off the lower left comer of the figure. Pressures act lower left to upper right on the outer hood identified by the nodes 6-7-8-11-10-9 (opposite C/D) and on the inner hoods identified by the nodes 22-23-24-29-28-27 and 40-41-42-47-46-45. Pressures act upper right to lower left on the outer hood identified by the nodes 98-99-100-103-102-101 (opposite A/B) and on the inner hoods identified by the nodes 82-83-84 88-87 and 64-65-66-71-70-69. The grid mesh (for the Helmholtz analysis) is spaced 1.5 inches everywhere on the dryer.
21
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information 3 -
1 103 7
97' C AB A0 1 4 96 18 78 36 60 Figure 4.4. Skirt and end plate low resolution load pressure nodes on the NMP2 dryer, with pressures acting from the outside of the dryer to the inside. MSL A and MSL B are off the right side of the figure; MSL C and MSL D are off the left side of the figure.
Skirt nodes are 2-4-18-36-60-78-96-104 and 2-5-19-37-61-79-97-104. End plate nodes are 20-25 and 21-26, 38-43 and 39-44, 62-67 and 63-68, and 80-85 and 81-86.
The grid mesh (for the Helmholtz analysis) is spaced 1.5 inches everywhere on the dryer.
22
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)))
Figure 4.5. Predicted loads on the low resolution grid identified in Figures 4.1 to 4.4, as developed by the ACM Rev. 4.1 R model, to 250 Hz. Low-numbered nodes are on the C-D side of the dryer, while high-numbered nodes are on the A-B side of the dryer. Conservative bias and uncertainties are included in these results.
23
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
((
(3)))
Figure 4.6. PSD of the maximum pressure loads predicted on the outer bank hood on the C-D side of the NMP2 dryer (top) and on the A-B side of the NMP2 dryer (bottom), as developed by the ACM Rev. 4.1R model. Maximum loads occur at the bottom comer of the outer bank hood opposite MSL C side (node 6) and MSL A side (node 100). Conservative bias and uncertainties are included in these results.
24
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
- 5. Uncertainty Analysis The analysis of potential uncertainty occurring at NMP2 consists of several contributions, including the uncertainty from collecting data on the main steam lines at locations other than the locations on Quad Cities Unit 2 (QC2) and the uncertainty in the ACM Rev. 4.1 model [3],
rebenchmarked as Rev. 4.1 R. QC2 dryer data at Original Licensed Thermal Power (OLTP) conditions were used to generate an uncertainty analysis for NMP2.
(3)
Bias is computed by taking the difference between the measured and predicted RMS pressure values for the sixteen pressures, and dividing the mean of this difference by the mean of the predicted RMS. RMS is computed by integrating the PSD across the frequency range of interest and taking the square root IE (RMSmeasured
- RMSpredicted
)
BIAS-= N BIIIN RMSpredicted where RMSmeasured is the RMS of the measured data and RMSprcdicted is the RMS of the predicted data. Summations are over the number of pressures examined.
Uncertainty is defined as the fraction computed by the standard deviation
- I (RMSmeasured - RMS"Predicted )2 UNCERTAINTY I I Z RMspredicted )
ACM Rev. 4. 1R bias and uncertainty results are compiled for specified frequency ranges of interest [9], and summarized in Table 5.1. Other random uncertainties, specific to NMP2, are summarized in Table 5.2 and are combined with the ACM results by SRSS methods to determine the total uncertainties for NMP2, which is shown in Table 5.3. Also shown in Table 5.3 are the ACM Rev. 4.1 total uncertainties and the conservative total uncertainties used in this report and the stress analyses. Use of the conservative total uncertainties ensures that any requirements as approved by the NRC for the NMP2 application of the ACM Rev. 4.1 model are not relaxed.
The most significant change between ACM Rev. 4.1 and 4.1R occurs in the frequency range 0 to 20 Hz, where the total uncertainty increases from 41.5% to 54.8%, or a factor of 1.548/1.415 = 9.4%.
25
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Table 5.1. NMP2 bias and uncertainty for specified frequency intervals. A negative bias indicates that the ACM overpredicts the QC2 data in that interval.
((
(3)))
Table 5.2. Bias and uncertainty contributions to total uncertainty for NMP2 plant data.
Er Table 5.3. NMP2 total uncertainty for specified frequency intervals.
Er (3)))
26
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
- 6. Conclusions The C.D.I. acoustic circuit analysis, using full-scale measured data for NMP2:
a) ((
(3)]
b) Predicts that the loads on dryer components are largest for components nearest the main steam line inlets and decrease inward into the reactor vessel.
27
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
- 7. References
- 1. Continuum Dynamics, Inc. 2005. Methodology to Determine Unsteady Pressure Loading on Components in Reactor Steam Domes (Rev. 6). C.D.I. Report No. 04-09 (Proprietary).
- 2. Continuum Dynamics, Inc. 2007. Bounding Methodology to Predict Full Scale Steam Dryer Loads from In-Plant Measurements, with the Inclusion of a Low Frequency Hydrodynamic Contribution (Rev. 0). C.D.I. Report No. 07-09 (Proprietary).
- 3. Continuum Dynamics, Inc. 2010. ACM Rev. 4.1: Methodology to Predict Full Scale Steam Dryer Loads from In-Plant Measurements. C.D.I. Report No. 10-09 Rev. 2 (Proprietary).
- 4. Nine Mile Point Unit 2 Drawings. 2007. Information provided in files 761E445AF, 197R624, 761E448, 761E448B, 3516-227-3, 0016010001729, 117C4972, 795E257, 921D597, 158B8534, 117C4519, 105D4673, and 795E260.
- 5. Structural Integrity Associates, Inc. 2012. July 2012 Nine Mile Point Unit 2 EPU Main Steam Line Strain Gage Data Reduction (Rev. 0). SIA Calculation Package No.
1101182.301.
- 6. Continuum Dynamics, Inc. 2014. Stress Re-Evaluation of Nine Mile Point Unit 2 Steam Dryer at 115% CLTP. C.D.I. Report No. 14-08 Rev. 0 (Proprietary).
- 7. Continuum Dynamics, Inc. 2014. Computation of Cumulative Usage Factor for the 115%
CLTP Power Level at Nine Mile Point Unit 2 with the Inboard RCIC Valve Closed. C.D.I.
Technical Note No. 14-04 Rev. 0 (Proprietary).
- 8. Communication from Enrico Betti. 2006. Excerpts from Entergy Calculation VYC-3001 (Rev. 3), EPU Steam Dryer Acceptance Criteria, Attachment I: VYNPS Steam Dryer Load Uncertainty (Proprietary).
- 9. NRC Request for Additional Information on the Hope Creek Generating Station, Extended Power Uprate. 2007. TAC No. MD3002. RAI No. 14.67.
- 10. Structural Integrity Associates, Inc. 2008. Nine Mile Point Unit 2 Strain Gage Uncertainty Evaluation and Pressure Conversion Factors (Rev. 1). SIA Calculation Package No. NMP-26Q-301.
- 11. Continuum Dynamics, Inc. 2005. Vermont Yankee Instrument Position Uncertainty. Letter Report dated 08/01/05.
- 12. Exelon Nuclear Generating LLC. 2005. An Assessment of the Effects of Uncertainty in the Application of Acoustic Circuit Model Predictions to the Calculation of Stresses in the Replacement Quad Cities Units 1 and 2 Steam Dryers (Revision 0). Document No. AM-21005-008.
28
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
- 13. Continuum Dynamics, Inc. 2007. Finite Element Modeling Bias and Uncertainty Estimates Derived from the Hope Creek Unit 2 Dryer Shaker Test (Rev. 0). C.D.I. Report No. 07-27 (Proprietary).
- 14. NRC Request for Additional Information on the Hope Creek Generating Station, Extended Power Uprate. 2007. RAI No. 14.79.
- 15. NRC Request for Additional Information on the Hope Creek Generating Station, Extended Power Uprate. 2007. RAI No. 14.110.
29
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Appendix A: Power Ascension Data Comparison This appendix summarizes the results of the power ascension from CLTP to 115% CLTP target power conditions at NMP2. Table A. 1 summarizes the results, referencing the target power level (in % CLTP), the Structural Integrity data file number (date and time), the minimum stress ratio computed by the real-time stress analysis, and the measured steam flow (in % CLTP).
It may be seen that all minimum stress ratios are greater than 2.0, with the exception of the inboard RCIC valve closed case, which is resolved by cycle counting and the computation of cumulative usage factor [7].
Figures A. 1 compare the MSL exclusion filtered signals for the target power levels of 100, 102.5, 105, 107.5, 110, 112.5, and 115% CLTP. Figures A.2 compare the MSL exclusion filtered signals for the target power levels of 105, 110, and 115% CLTP with the inboard RCIC valve closed (identifying the peak at 89.3 Hz on MSL B). Figures A.3 display the MSL exclusion filtered signals for 115% CLTP with the RCIC drain trap out-of-service, clearly showing the 92.5 Hz peak. Figure A.4 compares the MSL B exclusion filtered signals at the target power level of 115% CLUP with the inboard RCIC valve closed, while Figure A.5 compares the MSL B exclusion filtered signals at the target power level of 115% CLTP with the RCIC drain trap out-of-service.
Table A. 1. Tabulation of NMP2 power ascension data.
Target Power Level Structural Minimum Measured
(% CLTP) Integrity Data File Stress Ratio Steam Flow Name (% CLTP) 100.0 20120625022309 2.5 100.5 105.0 20120630165003 2.2 103.84 110.0 20120710180627 2.1 110.0 115.0 20120721142636 2.0 115.5 115.0 Inboard RCIC 20120904092600 1.5 115.8 Valve Closed 115.0 RCIC Drain Trap 20130524092644 2.0 115.5 Out-of-Service Target Power Level Structural Measured
(% CLTP) Integrity Data File Steam Flow Name (% CLTP) 102.5 20120628154002 101.62 105.0 Inboard RCIC 20120703013557 104.47 Valve Closed 107.5 20120708005230 107.13 110.0 Inboard RCIC 20120728161342 110.22 Valve Closed 112.5 20120719032244 112.53 30
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
((I (3)]
Figure A. Ia. Base curves (normal operation) for MSL A upper (top) and lower (bottom) for target power levels 100% CLTP (black curves), 102.5% CLTP (red curves), 105%
CLTP (blue curves), 107.5% CLTP (green curves), 110% CLTP (magenta curves),
112.5% CLTP (cyan curves), and 115% CLTP (gray curves).
31
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)))1 Figure A. lb. Base curves (normal operation) for MSL B upper (top) and lower (bottom) for target power levels 100% CLTP (black curves), 102.5% CLTP (red curves), 105%
CLTP (blue curves), 107.5% CLTP (green curves), 110% CLTP (magenta curves),
112.5% CLTP (cyan curves), and 115% CLTP (gray curves).
32
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)]
Figure A.lc. Base curves (normal operation) for MSL C upper (top) and lower (bottom) for target power levels 100% CLTP (black curves), 102.5% CLTP (red curves), 105%
CLTP (blue curves), 107.5% CLTP (green curves), 110% CLTP (magenta curves),
112.5% CLTP (cyan curves), and 115% CLTP (gray curves).
33
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)))
Figure A. 1d. Base curves (normal operation) for MSL D upper (top) and lower (bottom) for target power levels 100% CLTP (black curves), 102.5% CLTP (red curves), 105%
CLTP (blue curves), 107.5% CLTP (green curves), 110% CLTP (magenta curves),
112.5% CLTP (cyan curves), and 115% CLTP (gray curves).
34
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)))
Figure A.2a. Curves for MSL A upper (top) and lower (bottom) with the inboard RCIC valve closed, for target power levels 105% CLTP (black curves), 110% CLTP (red curves), and 115% CLTP (blue curves).
35
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)))1 Figure A.2b. Curves for MSL B upper (top) and lower (bottom) with the inboard RCIC valve closed, for target power levels 105% CLTP (black curves), 110% CLTP (red curves), and 115% CLTP (blue curves).
36
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
((
(3)]
Figure A.2c. Curves for MSL C upper (top) and lower (bottom) with the inboard RCIC valve closed, for target power levels 105% CLTP (black curves), 110% CLTP (red curves), and 115% CLTP (blue curves).
37
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)]
Figure A.2d. Curves for MSL D upper (top) and lower (bottom) with the inboard RCIC valve closed, for target power levels 105% CLTP (black curves), 110% CLTP (red curves), and 115% CLTP (blue curves).
38
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)]
Figure A.3a. Curves for MSL A (top) and MSL B (bottom) with the RCIC drain trap out-of-service, for the target power level 115% CLTP.
39
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)))
Figure A.3b. Curves for MSL C (top) and MSL D (bottom) with the RCIC drain trap out-of-service, for the target power level 115% CLTP.
40
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)))1 Figure A.4. Curves for MSL B at 115% CLTP target power conditions, with closure of the inboard RCIC valve (black curves) compared with the corresponding normal EPU operation curves (red curves). The curves are nearly identical except at a narrow band around the peak at 89.3 Hz.
41
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)))1 Figure A.5. Curves for MSL B at 115% CLTP target power conditions, with RCIC drain trap out-of-service (black curves) compared with the corresponding normal EPU operation curves (red curves). The curves are nearly identical except at a narrow band around the peak at 92.5 Hz.
42
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Figure A.6 plots the behavior of the root mean square (RMS) of the pressure measured at each of the eight MSL strain gage locations, from 0 to 250 Hz. This figure normalizes the RMS values at power levels above CLTP conditions by the RMS values of the eight signals at CLTP.
Also shown in this figure is a curve representing the corresponding velocity squared behavior, again beginning at CLTP. It may be seen that except for the MSL A Lower signal at 107.13%
CLTP measured steam flow, the RMS values all fall below the velocity squared curve.
" MSL A Upper
- MSL A Lower
- MSLB Upper
- MSL B Lower 1.35
- MSL C Upper
- MSL D Upper - -- -
1.3
- MSL D Lower : .. !* i....
1.25
'1) -__ Velocity Squared 1.2 N
° ,,,
1.15 - 6:
. . . . .i . . . . .i o . .. . :. . . . t 1.1 1.05 1
III I I II 0.95 100 102 104 106 108 110 112 114 116
% CLTP Steam Flow Figure A.6. Behavior of the MSL pressure signals (RMS normalized by the RMS at 100.5%
CLTP measured steam flow) plotted as a function of % CLTP measured steam flow, as identified in Table A.1. The black curve is the data trend assuming a velocity squared increase in load beginning at CLTP measured steam flow.
43
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information The corresponding behavior of stress ratio on the outer end plate as a function of power level is shown in Figure A.7. As expected from the results shown in Figure A.6, where MSL pressures are bounded by velocity squared, the stress ratio at this location on the dryer decreases by the inverse of velocity squared.
NMP2 Power Ascension 3
0d 2.8 P4~
rJ) 2.6 2.4 2.2 2
100 105 110 115 120
% CLTP Steam Flow Figure A.7. Stress ratio behavior plotted as a function of % CLTP measured steam flow on the outer end plate. The black closed circles are the computed stress ratios. The red curve is the trend assuming a velocity squared increase in load/stress to a stress ratio of 2.0 at 115.5% CLTP measured steam flow.
44
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Appendix B: Acoustic Circuit Model Rev. 4. 1R This appendix summarizes the differences between ACM Rev. 4.1 R and its predecessor ACM Rev. 4.1. Included is a sensitivity study highlighting the results of the model change.
Like all model-based measurement methodologies, the accuracy of the output (predicted acoustic loads) obtained with the acoustic circuit model (ACM) is affected by measurement noise and modeling fidelity. In the current context, noise originates from several sources, including readily quantifiable contributors such as strain gage measurement errors, signal contamination by MSL pipe vibration, and turbulent pressure fluctuations. Modeling fidelity is the additional predictive error associated with characterizing the acoustic fields, losses at the MSL entrance and along the pipe due to friction, and assumptions of one dimensional flow in the pipe. It also includes methods for discriminating between acoustic and structural vibration contributions, eliminating non-coherent signals, and properly identifying acoustic sources. A reasonable engineering approach is one that balances modeling requirements against the costs of model development and data acquisition. To compensate for the approximations made in the methodology, biases and uncertainties quantified by comparison against plant data (QC2) are applied to the calculated loads.
One of the challenges in implementing the ACM is locating the MSL strain gages so that the effects of noise contamination are minimized. Several considerations complicate this challenge: (1) the ideal strain gage placement is frequency dependent and, since the signal is not known before installation, the most important frequencies affecting optimal strain gage location are usually not available; (2) at a given frequency the optimal strain gage positioning for acoustic evaluation is dictated by the global coupled acoustic modes involving the four MSLs and their coupling into the steam dome - this means that strain gage placement rules based on considerations of a single line, while analytically more accessible, do not attain the level of acoustic modeling fidelity provided by the ACM; (3) to minimize structural contamination the strain gages should be located away from structural restraints; and (4) other constraints such as accessibility, ease of installation, and time to install, are at play.
(3) 45
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
((3 (3)))
46
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
((
(B.1)
I (B.2) I (B.3)
(3))) I 47
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
((
(B.4)
I (B.5a) t I
(B.5b)
(3)))1 48
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)))
49
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)))
50
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
((
(3) ))
51
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)))
52
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
((
(3)))
53
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
((
(3)))
54
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
((
(3)))1 55
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Appendix C: Comparison Between Rev. 4.1 and Rev. 4.1R This appendix compares pressure predictions on the QC2 and NMP2 steam dryers between ACM Rev. 4.1 and the rebenchmarked ACM Rev. 4.1R. The QC2 results, for the pressure transducers in front of MSL A, MSL B, MSL C, and MSL D, are shown in Figures C.1, and are compared with data measured on the dryer at these locations (these results form part of the rebenchmark). The NMP2 results, for six locations on the hoods, are shown in Figures C.2 for normal EPU operation, in Figures C.3 for RCIC inboard valve closed, and in Figures C.4 for RCIC drain trap out-of-service.
56
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
((I (3)))
Figure C. 1a. Comparison of ACM Rev. 4.1 and 4. 1R predictions with data measured on the QC2 dryer at OLTP conditions: P12 in front of MSL A (top); P3 in front of MSL B (bottom).
57
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information I
(3)))
Figure C. lb. Comparison of ACM Rev. 4.1 and 4.1 R predictions with data measured on the QC2 I dryer at OLTP conditions: P20 in front of MSL C (top); P21 in front of MSL D (bottom).
58
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)))
Figure C.2a. Comparison of ACM Rev. 4.1 and 4.1R predictions on the NMP2 data at 115%1 CLTP power for normal EPU operation: on the outer bank hood opposite MSL C and D (top); on the middle hood on the MSL C and D side of the dryer (bottom).
59
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
((
(3)))
Figure C.2b. Comparison of ACM Rev. 4.1 and 4.1R predictions on the NMP2 data at 115%
CLTP power for normal EPU operation: on the inner bank hood on the MSL C and D side of the dryer (top); on the inner bank hood on the MSL A and B side of the dryer (bottom).
60
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
((I (3)]
Figure C.2c. Comparison of ACM Rev. 4.1 and 4.IR predictions on the NMP2 data at 115%00 CLTP power for normal EPU operation: on the middle bank hood on the MSL A and B side of the dryer (top); on the outer bank hood opposite the MSL A and B side of the dryer (bottom).
61
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)]
Figure C.3a. Comparison of ACM Rev. 4.1 and 4.1R predictions on the NMP2 data at 115%
CLTP power for RCIC inboard valve closed: on the outer bank hood opposite MSL C and D (top); on the middle hood on the MSL C and D side of the dryer (bottom).
62
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)]
Figure C.3b. Comparison of ACM Rev. 4.1 and 4.1R predictions on the NMP2 data at 115%
CLTP power for RCIC inboard valve closed: on the inner bank hood on the MSL C and D side of the dryer (top); on the inner bank hood on the MSL A and B side of the dryer (bottom).
63
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information
((I (3)]
Figure C.3c.Comparison of ACM Rev. 4.1 and 4.LR predictions on the NMP2 data at 115%
CLTP power for RCIC inboard valve closed: on the middle bank hood on the MSL A and B side of the dryer (top); on the outer bank hood opposite the MSL A and B side of the dryer (bottom).
64
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)))1 Figure C.4a. Comparison of ACM Rev. 4.1 and 4.1R predictions on the NMP2 data at 115%
CLTP power for RCIC drain trap out-of-service: on the outer bank hood opposite MSL C and D (top); on the middle hood on the MSL C and D side of the dryer (bottom).
65
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)]
Figure C.4b. Comparison of ACM Rev. 4.1 and 4.1R predictions on the NMP2 data at 115%
CLTP power for RCIC drain trap out-of-service: on the inner bank hood on the MSL C and D side of the dryer (top); on the inner bank hood on the MSL A and B side of the dryer (bottom).
66
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information 1[
(3)]
Figure C.4c. Comparison of ACM Rev. 4.1 and 4.1R predictions on the NMP2 data at 115%
CLTP power for RCIC drain trap out-of-service: on the middle bank hood on the MSL A and B side of the dryer (top); on the outer bank hood opposite the MSL A and B side of the dryer (bottom).
67
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Appendix D: MSL A Upper Strain Gage Signals The first time that data were taken at 110% CLTP target power (on 10 July 2012), one of the strain gage pairs (identified as channels in Table 3.1) on MSL A upper gave elevated noise levels. It was determined that the signals from that strain gage pair and its opposite pair would be disregarded when converting to pressure. While this approach normally increases the baseline noise level, in this case it reduced the baseline noise because of the bad strain gage reading.
Subsequent to the collection of these data, the plant underwent a scram. The plant recovered 110% CLTP target power on 18 July 2012 and acquired data at 115% CLTP target power on 21 July 2012. These data were converted to pressures assuming the same strain gage channel pairs as for the 10 July data. Further review of the data at 115% CLTP target power concluded that the noise level in the MSL A upper strain gage was in fact normal during this dataset, and that the conversion to pressure should apply all four strain gage pairs. Thus, the 115% dataset used for the load definition report included the four strain gage pairs at MSL A upper. Table D. 1 summarizes the status of the four pairs during power ascension. Figure D.1 compares the two pressure signals at MSL A upper.
I Table D. 1. Tabulation of active strain gage pairs on MSL A upper during power ascension data.
Target Power Level Structural Active Active Active Active
(% CLTP) Integrity Data File Pairs Pairs Pairs Pairs Name 100.0 20120625022309 1 2 3 4 102.5 20120628154002 1 2 3 4 105.0 20120630165003 1 2 3 4 107.5 20120708005230 1 2 3 4 110.0 [*] 20120710180627 2 4 112.5 [*] 20120719032244 2 4 115.0 [*] 20120721142636 2 4 115.0 20120721142636 1 2 3 4 105.0 Inboard RCIC 20120703013557 1 2 3 4 Valve Closed 110.0 Inboard RCIC 20120728161342 1 2 3 4 Valve Closed 115.0 Inboard RCIC 20120904092600 1 2 3 4 Valve Closed 115.0 RCIC Drain 20130524092644 1 2 3 4 Trap Out-of-Service I
[*]: Strain gage pair 3 was giving elevated noise level, so this pair and its opposite pair (strain gage pair 1) were not included when computing the pressure at MSL A Upper.
68
This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information (3)))
Figure D. 1. Exclusion filtered pressure measured on the NMP2 main steam lines at 115% CLTP target power conditions for MSL A, comparing the use of strain gage pairs 2 and 4 with the use of all four strain gage pairs.
69