ML053200222
| ML053200222 | |
| Person / Time | |
|---|---|
| Site: | Hope Creek  |
| Issue date: | 10/31/2005 |
| From: | Continuum Dynamics |
| To: | Office of Nuclear Reactor Regulation, Public Service Enterprise Group |
| References | |
| 4500283344, LCR H05-01, LR-N05-0258 05-17 | |
| Download: ML053200222 (34) | |
Text
Attachment 18 LR-N05-0258 LCR H05-01 HOPE CREEK GENERATING STATION FACILITY OPERATING LICENSE NPF-57 DOCKET NO. 50-354 REQUEST FOR LICENSE AMENDMENT EXTENDED POWER UPRATE Hydrodynamic Loads on Hope Creek Unit 1 Steam Dryer to 200 Hz CDI Report 05-17, Revision I October 2005
C.D.I. Report No. 05-17 Hydrodynamic Loads on Hope Creek Unit 1 Steam Dryer to 200 Hz Revision 1 Prepared by Continuum Dynamics, Inc.
34 Lexington Avenue Ewing, NJ 08618 Prepared under Purchase Order No. 4500283344 for Nuclear Business Unit, PSEG Nuclear LLC Materials Center, Alloway Creek Neck Road Hancocks Bridge, NJ 08038 Approved by Alan J. Bilanin October 2005
Executive Summary Measured in-plant strain gage / pressure time-history data in the four main steam lines of Hope Creek Unit 1 (HC1) are processed by a dynamic model of the steam delivery system to predict loads on the steam dryer. These measured data are first positioned on the four main steam lines, and then used to extract acoustic sources in the system. A validated acoustic circuit model is used to predict the fluctuating pressures anticipated across components of the steam dryer in the reactor vessel. The hydrodynamic load data may then be used by a structural analyst to assess the structural adequacy of the steam dryer in HC1.
This effort provides PSEG with a dryer dynamic load definition that comes directly from measured in-plant data and the application of a validated acoustic circuit model, at a power level where the strain gage / pressure data were acquired.
Table of Contents Section Page Executive Summary..........................................................
i Table of Contents.............................
ii
- 1. Introduction............................................................................
1
- 11. Modeling Considerations..........................................................
2 2.1 Helmholtz Analysis..........................................................
2 2.2 Acoustic Circuit Analysis....................................................
3 III. Input Pressure Data...........................................................
5 IV. Results.................................................................................
11 V. Peak Loads Sensitivity and Exceedance..................
19 VI. Power Level Behavior..........................................................
22 VII. Error Analysis.......................
28 VIII. Conclusions...........................................................................
29 IX. References.............................................................................
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I. Introduction In Spring 2005 Exelon installed new stream 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 the last 30 years. As a means for confirming the adequacy of the steam dryer, the QC2 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 model under development by Continuum Dynamics, Inc. for several years [1]. The results of this benchmark exercise [2] confirmed the predictive ability of the acoustic circuit model for pressure loading across the dryer. This model, validated against the Exelon full scale data, is used in this effort.
This report applies this validated acoustic circuit model to the Hope Creek Unit 1 (HC1) steam dryer and main steam line geometry. Data obtained from the four main steam lines were used to generate predictions of the pressure loading on the HC 1 dryer at seven power levels from 50% to 100%. The highest loading was predicted for the 96% power level. The magnitude of these load predictions is similar to previous load predictions for Dresden Unit 2 and Unit 3, although greater uncertainty exists in the HC1 loads as a consequence of the locations of the strain gages - more than 200 feet from the steam dome.
II. Modeling Considerations The HC1 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.
2.1 Helmholtz Analysis A cross-section of the steam dome (and steam dryer) is shown below in Figure 2.1, with HCI dimensions as shown.
The complex three-dimensional geometry is rendered onto a uniformly-spaced rectangular grid (with mesh spacing of approximately 1.5 inches), and a solution is obtained for the Helmholtz equation 82p+
=
2
+
a2
(=0 we ih s
a2 a
where P is the pressure at a grid point, co is frequency, and a is acoustic speed in steam.
R a'a b a
I Ik:
, b _,_aa_ b-9 i
e f
l k
9 Figure 2.1.
Cross-sectional description of the steam dome and dryer, with the verified HC1 dimensions of a' = 15.0, a = 17.5 in, b = 13.5 in, c' = 21.0 in, c = 15.0 in, d = 16.0 in, e = 21.0 in, f= 73.0 in, g = 163.0 in, i = 96.5 in, j = 183.0 in, k = 120.0 in, and R
= 125.5 in.
2
This equation is solved for incremental frequencies from 0 to 200 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 O N
-cc-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.
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 component dimensions, and in particular 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 200 Hz, acoustic wavelengths are approximately 8 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 0
I' i
I Ln.
Figure 2.2. Schematic of an element in the acoustic circuit analysis, with length L and cross-sectional area A.
3
Application of acoustic circuit methodology generates solutions for the fluctuating pressure P. and velocity un in the nrh element of the form P. = [Ane In n +Bneik2nXn Je int Un =
I [(O+Unkln )AneikinXn pa2 kin
+ tJk 2 n )Bneik2nXn e'wt k 2 n where harmonic time dependence of the form ei"t has been assumed. The wave numbers kin and k2n are the two complex roots of the equation kn2 +i 21 (,(1)+Unkn )--2 (t
nYn)
=0 Dna a
where fn is the pipe friction factor for element n, Dn is the hydrodynamic diameter for element n, and i = Ti.
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 main steam line piping geometry is summarized in Table 2.1.
Table 2.1. Main steam line lengths at HCI. The main steam lines are 26 inch Schedule 80 (ID = 23.647 in) and 28 inch Schedule 80 (ID = 26.267 in).
Main Steam Line Length of 26 inch Length of 28 inch Length of 28 inch Pipe (fit)
Pipe to First Strain Pipe to Second Strain Gage (ft)
Gage (ft)
A 168.05 39.33 89.33 B
180.09 39.33 89.33 C
175.88 39.33 89.33 D
164.21 39.33 89.33 4
III. Input Pressure Data Strain gages were mounted on the four main steam lines. The seven data sets examined here is summarized in Table 3.1, and includes the eight strain gage measurements, as identified in Table 3.2. Recorded strain is converted to pressure by the formula P =2.537 Ch where P is the pressure in psid and ch is the hoop strain in ps [3].
Table 3.1. Data sets considered for HC1.
Data Set 20050707103347 20050211035248 20050210212726 20050207153500 20050906080538 20050201083053 20050131074623 Feed Flow (106 lbs/hr) 14.40 14.12 13.83 12.96 10.90 9.42 7.42 Data Rate (samples/sec) 1024 1024 1024 1024 1024 1024 1024 Pertinent Commnents 100% Power 98% Power 96% Power 90% Power 76% Power 65% Power 50% Power Table 3.2. Strain gage identification for HC 1.
Strain Gage Number 1
2 3
4 S
6 7
8 Strain Gage MSL Location A: first strain gage A: second strain gage B: first strain gage B: second strain gage C: first strain gage C: second strain gage D: first strain gage D: second strain gage Strain Gage Channel Number STGA-AOI-233 STGA-A03-237 STGA-BO1-62 STGA-B03-67 STGA-CO1-582 STGA-C02-587 STGA-DO1-402 STGA-D02-407 Examination of the frequency content of these data sets shows pressure spikes at 72, 108, and 142 Hz, depending on power level and strain gage. Past experience suggests that the ERV standpipes are typically the source of pressure spikes above 50 Hz. Because the strain gages are positioned downstream of the standpipes, the acoustic circuit model was modified to substitute a standpipe source for an inlet source, on each main steam line, above a frequency of 50 Hz. In addition, the large distances from the main steam line inlet to the locations of the strain gages -
over 200 feet - also necessitated the zeroing of the acoustic damping in the main steam lines.
Table 3.3 summarizes the characteristics of the collected data at each of the seven power levels. Note that measured signals below 0.0009 psid2/Hz are considered noise and have been 5
filtered from the analysis. Table 3.3 suggests that examination of the pressures obtained from the strain gages is alone not sufficient to determine which power level leads to the maximum pressure load prediction. Rather, the acoustic circuit model must be used, and when it is, the 96% power level gives the highest pressure loading on the HCI steam dryer (see Section 6 for additional details). This result is supported by [4]. The power spectral density functions (PSD) for 96% power are shown in Figure 3.1.
Table 3.3. Summary of the pressure data obtained from the eight strain gages at all power levels examined for HC1.
Maximum Pressure (psid)
Strain Gage 50%
65%
76%
90%
96%
98%
100%
Number Power Power Power Power Power Power Power 1
0.394 0.271 0.313 0.473 0.553 0.486 0.355 2
0.307 0.388 0.0 0.965 1.784 1.016 1.082 3
0.458 1.087 0.0 2.268 1.690 1.348 1.392 4
0.396 0.831 2.608 1.518 0.701 0.611 0.732 5
0.310 0.724 0.117 0.309 0.514 0.192 0.155 6
0.493 0.638 0.380 0.852 1.073 0.832 0.713 7
0.398 0.321 0.185 0.432 0.519 0.459 0.361 8
0.514 0.527 0.0 0.357 0.303 0.369 0.227 RMS Pressure (psid)
Strain Gage 50%
65%
76%
90%
96%
98%
100%
Number Power Power Power Power Power Power Power 1
0.108 0.129 0.073 0.099 0.140 0.120 0.098 2
0.094 0.113 0.0 0.265 0.315 0.267 0.282 3
0.115 0.281 0.0 0.362 0.412 0.320 0.326 4
0.139 0.210 0.448 0.223 0.194 0.158 0.166 5
0.094 0.204 0.042 0.078 0.160 0.059 0.047 6
0.145 0.157 0.099 0.189 0.300 0.217 0.171 7
0.112 0.105 0.075 0.117 0.146 0.119 0.101 8
0.129 0.145 0.0 0.085 0.081 0.096 0.061 6
cn qe 0.007 0.006 0.005 0.004 0.003 0.002 0.001 0
I..
0 50 100 150 Frequency (Hz) 200 MSL A: SG 2 0.015 N
V)
PQ.
0.01 0.005 I
. I l--------- ------- ------- ------
n 0
50 100 150 200 Frequency (Hz)
Figure 3.1 a. PSD comparison of strain gage data at 96% power, converted to pressure, for main steam line A: strain gage number 1 (top) and strain gage number 2 (bottom).
7
rn Cnt V) 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0
0.012 0.01 0.008 0.006 0.004 0.002 0
0 50 100 150 Frequency (Hz) 200 MSL B: SG 4 l
I A....................
.--.............------I................................
I...
0 50 100 150 Frequency (Hz) 200 Figure 3.1b. PSD comparison of strain gage data at 96% power, converted to pressure, for main steam line B: strain gage number 3 (top) and strain gage number 4 (bottom).
8
MSLC: SG5 N
a.)
C/S 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0
t i.
0 50 100 150 Frequency (Hz) 200 MSL C: SG 6 0.05 0.04 0.03 0.02 0.01 0
AD..........................
i i.
, ^ i,
0 50 100 Frequency (Hz) 150 200 Figure 3.1c. PSD comparison of strain gage data at 96% power, converted to pressure, for main steam line C: strain gage number 5 (top) and strain gage number 6 (bottom).
9
P-v ut, 0.012 0.01 0.008 0.006 0.004 0.002 0
0.0014 0.0012 0.0001 0.0008 0.0006 0.0004 0.0002 0
......................... I...
0 50 100 Frequency (Hz) 150 200 MSL D: SG 8
................ -- - - - - - - - - -...... n.............................
- 81.,.......................................................---
t) 50 100 150 Frequency (Hz) 200 Figure 3.1d. PSD comparison of strain gage data at 96% power, converted to pressure, for main steam line D: strain gage number 7 (top) and strain gage number 8 (bottom).
10
IV. Results The main steam line pressure data are used to drive the validated acoustic circuit model for the HC1 steam dome and main steam lines. The results are presented here on a low-resolution grid (shown schematically in Figures 4.1 to 4.4) by summarizing the peak and RMS pressures expected over the time interval provided in the original data. These nodal results for 96% power level are shown in Figure 4.5. The Minimum Error solution, as defined in [2], is used.
It may be seen that the peak loads are no higher than 1.2 psid. This loading level is consistent with previous results seen for Dresden Unit 2 (peak loads of 0.42 psid at OLTP and 0.74 psid at EPU) and Unit 3 (peak loads of 1.02 psid at OLTP and 1.12 psid at EPU), and is much less than predicted for Quad Cities Unit 1 and Unit 2 [5]. The peak loads on either side of the steam dryer in HCI are shown in Figures 4.6 and 4.7.
Comparisons may be further shown at the front edge of the cover plates, opposite the A-B and C-D sides of the dryer, at nodes 8 and 99 (see Figures 4.1 and 4.5 for specific locations). On the A-B side of the dryer (node 99), the maximum predicted pressure difference across the cover plate is 1.142 psid at predominantly 72 Hz. On the C-D side of the dryer (node 8), the maximum predicted pressure difference across the cover plate is 0.610 psid, occurring at 29 Hz and 72 Hz.
11
Figure 4.1. Bottom plates pressure node locations, with pressures acting downward in the notation defined here.
12
.I0 I
Figure 4.2.
Upper plates pressure node locations, with pressures acting downward in the notation defined here.
13
I Figure 4.3. Vertical plates: Pressures acting left to right on panels 6-11, 22-29, and 40-47; acting right to left on panels 64-71, 82-89, and 98-103.
14
2 I
34Sr p-o Figure 4.4. Skirt plates: Pressure acting on the outer dryer 0/180 surfaces and the skirt.
15
0.-
8........
aa 0 6 Add i~t k
A A
0.4 Ct 0.2 0 0 20 40 60 80 100 120 Node Number 0.32 0_
- 0.2 C/)
0.15
~~~~~~~~.t.2 -.........--
'---'t.
_ -1 rI--
r A.
- 1 J E 0)0 0
20 40 60 80 100 120 Node Number Figure 4.5. Predicted loads at 96% power as developed by the current methodology to 200 Hz.
Node 8 is located at the back edge of the cover plate opposite the D main steam line, while node 99 is located at the back edge of the cover plate between the A and B main steam lines.
16
C,,a.)
N C,,
0.6 -
0.4 0.2 0
-0.2
-0.4
-0.655 55.5 56 56.5 57 Time (sec) 0.05 0.04 0.03 0.02 0.01 A
_,7, 50 100 t
A l...
W0 50 100 Frequency (Hz)
Figure 4.6. Time and PSD of the predicted pressure load at node 8.
150 200 17
1.5 I
1.5
-o 0.0s
-4 0
M 0.0
-0.5 0
.035.....
0.035 0.03 o 0.025
=
I-
%S 0.015 0.01 0.005 --- -- - - --- - -.
0 0 50 100 150 200 Frequency (Hz)
Figure 4.7. Time and PSD of the predicted pressure load at node 99.
18
V. Peak Loads Sensitivity and Exceedance The 96% power results can be examined to develop the load exceedance probability function for peak pressure loads on either side of the steam dryer (nodes 8 and 99). For the predictions shown previously in Figures 4.6 and 4.7, respectively, the predicted discrete pressures (positive and negative) are sorted into bins of width 0.01 psid and plotted, as shown in Figure 5.1.
The distributions for nodes 8 and 99 are normnally distributed, and Gaussian functions of the form p(P)
A e-p 2 /2a2 can be curvefit to the collected data, resulting in standard deviations of a = 0.2973 psid for node 8 and a = 0.2946 psid for node 99. Then, the time for a peak load P to occur can be found from the exponential portion of the above equation. The results are shown in Figure 5.2.
19
C) 0 00 O
U3 0
0 0.U S
co~
c) 0 C
00 0
0cj O
z
-0 z
600 500 400 300 200 100 0
500 400 300 200 100 0
Node 8
.6o
............V 1.5
-1
-0.5 0
0.5 Pressure (psid) 1 1.5 Node 99
-1.5
-1
-0.5 0
0.5 1
1.5 Pressure (psid)
Figure 5.1. Probability density functions for predicted pressures at node 8 (top) and node 99 (bottom).
20
109 C.)
0 0
C.)
SE 107 105 1000 10 0.1 0.001 Node 8
. I.
0 0
00 0
U 0
9
__---------------t--o-----------__
1 1.5O@
I 0
10-5 0
0.5 1
1.5 Peak Pressure (psid)
Node 99 2
2.5 109 Cn C.)
0 0
4.)O
_E 5-107 105 1000 10 0.1 0.001 r---
,-O-
- 00 0:
- 0 I,
I.
I F------- ------ '-----..........------...----
10-5 0
0.5 1
1.5 Peak Pressure (psid) 2 2.5 Figure 5.2. Peak pressure load exceedance for predicted pressures at node 8 (top) and node 99 (bottom). Typical times: 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> = 3,600 sec; 1 day = 86,400 sec; 1 month = 2.6 x 106 sec; 1 year= 3.15 x 107 sec; 31.7 years = 109 sec.
21
VI. Power Level Behavior As discussed previously, additional strain gage / pressure data were supplied by PSEG at lower power levels, so that predictions could be made of the behavior of peak load on the dryer.
Figure 6.1 illustrates the behavior of the PSD at a function of power level, for each of the eight strain gages. Calculations at all power levels give the pressure and RMS comparisons shown in Figure 6.2. The strain gage data (summarized in Table 3.3) show that peak strains occur in the main steam lines at 96% power. However, the acoustic circuit analysis shows that steam dryer Rev 1 load at one position on the dryer (node 99) is actually peak at 98% power (as shown in Figure 6.2).
22
co L5 q) 0.01 0.005 0
0.025 r 50 100 150 Frequency (Hz) 200 MSL A: SG 2 I
N e'r Cn P.-4 0.02 0.015 0.01 0.005 I
100% Power 98% Power 96% Power 90% Power 76°%' Power 65°. (%
Power so 50% Powcr I
... I....................-
I,-.........---------_
-Ii 4 A L
1..
0 0
50 100 Frequency (Hz) 150 200 Figure 6.1 a. PSD of strain gage / pressure data at strain gage I (top) and strain gage 2 (bottom).
Frequency peaks above 50 Hz are consistent with the ERV standpipes. The seven colors represent the seven power levels examined. Frequency content at 60, 120, and 180 Hz has been filtered. The noise floor has not been removed.
23
MSL B: SG 3 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0
0.05
.I--
b 100% Power 98% Power 96%X0 Power 90% Power.........................
76% Power 65%,, Power 50%o Power tioPve..............................................
\\
0 50 100 Frequency (Hz) 150 200 MSLB: SG4 ri a) 0.04 0.03 0.02 0.01 100% Power 98% Power 96% Power 90% Power 760%o Power
.650,% Power
- 1.
,'i
Ni
S lsE _n w
XA 00 0 0 50 100 Frequency (Hz) 150 2(
Figure 6.lb. PSD of strain gage / pressure data at strain gage 3 (top) and strain gage 4 (bottom).
Frequency peaks above 50 Hz are consistent with the ERV standpipes. The seven colors represent the seven power levels examined. Frequency content at 60, 120, and 180 Hz has been filtered. The noise floor has not been removed.
24
N V:
0.03 0.025 0.02 0.015 0.01 0.005 0
MSLC: SG5 100% Power w e 98% Power 96% Power
- __,__90% Power 76% Pow cr
. D()0t1'o PoxverI:
0 50 100 Frequency (Hz) 150 200 MSL C: SG 6 N
._~
uM AL 0.05 0.04 0.03 0.02 0.01 A
,I 100% Power 98% Power 96% Power 90% Power 7f 76% Power 65% Power
...I.......................
50% Power.
I :
\\
I -.1 -
-I, n A 11 0
50 100 150 200 Frequency (Hz)
Figure 6.1c. PSD of strain gage / pressure data at strain gage 5 (top) and strain gage 6 (bottom).
Frequency peaks above 50 Hz are consistent with the ERV standpipes. The seven colors represent the seven power levels examined. Frequency content at 60, 120, and 180 Hz has been filtered. The noise floor has not been removed.
25
.N-e Z
Ct)-e V)
Ct 04 0.012 0.01 0.008 0.006 0.004 0.002 0
0.012 0.01 0.008 0.006 0.004 0.002 A
0 50 100 150 Frequency (Hz) 200 MSL D: SG 8 I
I
£ 100% Power 98% Power 1
96% Power 90% Power 760% Powcr 76 ~ p l...............
65% Power 50% Powe L.........
A.
0 50 100 150 200 Frequency (Hz)
Figure 6.1 d. PSD of strain gage / pressure data at strain gage 7 (top) and strain gage 8 (bottom).
Frequency peaks above 50 Hz are consistent with the ERV standpipes. The seven colors represent the seven power levels examined. Frequency content at 60, 120, and 180 Hz has been filtered. The noise floor has not been removed.
26
-4 03 b r-42a)
E
Q E
EXCt I
~a 1 -4 C,E a)
&-4 1.4 1.2 1
0.8 0.6 0.4 0.2 0
1 450 60 70 80 Power Level (%)
90 100 "C-1 -4 C2 a) 0.4 0.35 0.3 0.25 0.2 0.15, 0.1 0.05 0
54 L......
I D
60 70 80 Power Level (%)
90 100 Figure 6.2. Summary of maximum differential pressure (top) and RMS pressure (bottom) as a function of power level in HCI.
27
VII. Error Analysis The analysis of potential uncertainty occurring at HC1 consists of two contributions: the uncertainty when using a single strain gage at each location with the acoustic circuit methodology, and the uncertainty with respect to position of these strain gages relative to the strain gages at QC1 and QC2.
Through an extensive analysis, Exelon [6] concluded that the best estimate of the overall uncertainty for steam dryer acoustic circuit analysis methodology was that the error would range from a maximum under prediction of 3.5% to a maximum over prediction of 14.5%. These estimates are based on the use of strain gage pairs positioned on the four main steam lines at approximately 10 and 40 feet downstream of the steam dome. However, in a recent report [4],
Structural Integrity Associates argued that there is conservatism built into the data collected at the single strain gages in Hope Creek, as compared against the data collected from strain gage pairs as was done at Quad Cities. SIA suggests that this conservatism is bounded by a factor of between 1.16 and 2.40 [4]. It is suggested that no credit be taken for conservatism in the number of strain gages by Hope Creek at this time.
The second uncertainty arises from the actual locations of the strain gage pairs at Hope Creek. In a similar analysis for Vermont Yankee [7], it was concluded that an average error of 42.1% is possible if the main steam line data collection locations are farther downstream than on Quad Cities. Since no credit was taken for the number of strain gages used, it is suggested that 42.1% be used for the uncertainty in the strain gage locations. Thus, an SRSS of the two uncertainties (an average of 8.0% from the Exelon analysis and 42.1% from the Vermont Yankee analysis, or 42.9%) is sufficient to bound all uncertainties that exist in this analysis, until such time that strain gage pairs can be repositioned and installed closer to the steam dome, as was done in Quad Cities.
28
VIII. Conclusions The C.D.I. acoustic circuit analysis, using in-plant measured data from HC1 a) Determines that steam dryer differential hydrodynamic loads at 96% power are less than 1.2 psid.
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.
c) Determines that the highest differential pressure load on the dryer occurs at 72 Hz.
The following additional work is suggested:
It is highly recommended that strain gages be positioned much closer to the steam dryer.
This method has been used successfully by Exelon, and load uncertainty levels of less than 10% have been achieved.
29
IX. 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. 2005. Evaluation of Continuum Dynamics, Inc. Steam Dryer Load Methodology Against Quad Cities Unit 2 In-Plant Data Revised Hydrodynamic Loads on Quad Cities Unit 2 Steam Dryer (Revision 0). C.D.I. Report No. 05-10.
- 3. Structural Integrity Associates, Inc. Letter Reports. "Hope Creek Strain Gage Data" (14 July 2005) and "Hope Creek February 2005 Strain Gage Data - ASCII Files" (01 August 2005).
- 4. Structural Integrity Associates, Inc. Letter Report. "Hope Creek Steam Dryer Hydrodynamic Loads Assessment" (11 October 2005). SIA Report No. SIR-05-258 Revision B.
- 5. Continuum Dynamics, Inc. 2005. Revised Hydrodynamic Loads on Quad Cities Unit 2 Steam Dryer to 200 Hz, with Comparison to Dresden Unit 2 and Dresden Unit 3 Loads (Revision 0). C.D.I. Report No. 05-01.
- 6. 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.
- 7. Continuum Dynamics, Inc. 2005. Vermont Yankee Instrument Position Uncertainty. Letter Report Dated 01 August 2005.
30