ML070810365

C.D.I. Report No. 07-01NP, Rev. 0, Revised Hydrodynamic Loads on Hope Creek Unit 1 Steam Dryer to 200 Hz.

ML070810365
Person / Time
Site:	Hope Creek
Issue date:	02/28/2007
From:	Bilanin A Continuum Dynamics
To:	Office of Nuclear Reactor Regulation
References
4500378760, LCR H05-01, Rev 1, LR-N07-0055 C.D.I. Report No. 07-01NP, Rev 0
Download: ML070810365 (28)

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Attachment 2 LR-N07-0055 LCR H05-01, Rev. 1 Hope Creek Generating Station Facility Operating License NPF-57 Docket No. 50-354 Supplement to Request for License Amendment Extended Power Uprate C.D.I. Report No. 07-01NP Revised Hydrodynamic Loads on Hope Creek Unit 1 Steam Dryer to 200 Hz Revision 0 February 2007

This Report Does Not Contain C.D.I. Proprietary Information C.D.I. Report No. 07-01NP Revised Hydrodynamic Loads on Hope Creek Unit 1 Steam Dryer to 200 Hz Revision 0 Prepared by Continuum Dynamics, Inc.

34 Lexington Avenue Ewing, NJ 08618 Prepared under Purchase Order No. 4500378760 for Nuclear Business Unit, PSEG Nuclear LLC Materials Center, Alloway Creek Neck Road Hancocks Bridge, NJ 08038 Approved by A

jj1dqA4 a/a-lt4 Alan J. Bilanin February 2007

This Report Does Not Contain C.D.I. Proprietary Information Executive Summary Measured in-plant pressure time-history data (acquired in February 2007) in the four main steam lines of Hope Creek Unit I (HC1), at the eight strain gage locations at Current Licensed Thermal Power (CLTP), are processed by a dynamic model of the steam delivery system to predict loads on the steam dryer. These measured data are used with a validated acoustic circuit model 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 HC 1.

These loads are compared with in-plant time-history data taken previously (in May 2006), in which several strain gages were not working on main steam lines C and D. In addition, measured one-eighth scale pressure time-history data at corrected CLTP conditions are also compared to the recent full-scale pressure time-history data as well.

This effort provides PSEG with a comparison between previous and present in-plant data, and with subscale test data, and the application of a validated acoustic circuit model, at power levels where the pressure data were acquired.

This Report Does Not Contain C.D.I. Proprietary Information Table of Contents Section Page Executive Summary .................................................................. i T able of C ontents ..................................................................... ii

1. Introduction ............................................................................ 1

2. Modeling Considerations ............................................................ 2

3. Input Pressure Data .................................................................. 3 3.1 February 2007 Data ......................................................... 3 3.2 May 2006 Data ............................................................... 8 3.3 January 2007 Subscale Data ................................................ 8 4 . R esults ................................................................................ 18

5. C onclusions ........................................................................... 23

6. R eferences ............................................................................. 24 ii

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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 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 I (HCI) steam dryer and main steam line geometry. Recent data obtained from the four main steam lines are used to generate predictions of the pressure loading on the HCI dryer at Current Licensed Thermal Power (CLTP) conditions. These data are compared with main steam line data taken previously at HCI, when strain gage failures occurred and main steam line data had to be approximated [3]. In addition, data obtained from a one-eighth scale model of the HC1 steam delivery system are used to generate full-scale predictions of the pressure loading on the HC1 dryer at CLTP conditions as well [4].

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2. 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. The approach followed in the current analysis is identical to the approach discussed and taken in [3] and is not repeated here, with the exception of summarizing the locations of the strain gages on the four main steam lines, as shown in Table 2.1.

Table 2.1. Main steam line lengths at HC 1. The main steam lines are 26 inch Schedule 80 (ID = 23.647 in) to the strain gages.

Main Steam Line Distance to First Distance to Second Strain Gage (ft) Strain Gage (ft)

A 9.71 45.83 B 9.71 45.71 C 9.71 45.71 D 9.71 45.83 2

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3. Input Pressure Data Three sets of data are analyzed in this report: strain gage data collected in February 2007, with all eight strain gage locations (two per main steam line) functioning and providing data; strain gage data collected in May 2006 with strain gages failures on main steam lines C and D (separately reported in [3]); and subscale pressure transducer data collected in January 2007 as part of an effort to calibrate the Mach number in the subscale facility (the experiment is separately reported in [4]. All test conditions are at CLTP conditions.

3.1 February 2007 Data Strain gages were mounted on the four main steam lines in HC1. The in-plant data examined here are summarized in Table 3.1, and include eight strain gage measurements [5].

Recorded strain is converted to pressure with the factors provided in [6].

Table 3.1. Data set considered for HC 1.

Data Set Strain Gage Data Rate Pertinent Voltage (V) (samples/sec) Comments 20070208110642 0.01 1024 CLTP 20070208105816 10.0 1024 CLTP Because of the small level of voltage across the strain gages in the first set of data, it is postulated that these data contain only system noise, and that this noise can be removed from the second set of data, which includes the signal plus the noise. Several frequency ranges were also excluded from these data, for the reasons given in Table 3.2.

Table 3.2. Exclusion frequencies for HC1.

Frequency Interval (Hz) Exclusion Cause 0.0 to 2.0 Mean 59.8 to 60.2 60 Hz Line Noise 119.8 to 120.2 120 Hz Line Noise 179.8 to 180.2 180 Hz Line Noise 104.9 to 105.3 B Recirculation Pump 106.5 to 106.9 A Recirculation Pump The resulting main steam line pressures are shown in Figures 3.1, while the coherence between the upper and lower strain gages is shown in Figures 3.2. Pressure levels are shown in Table 3.3.

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This Report Does Not Contain C.D.I. Proprietary Information I((

(3)))

Figure 3.1. Main steam line data collected in February 2007: upper locations are black, while lower locations are red; main steam line A (top); main steam line B (bottom).

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Figure 3.1. Main steam line data collected in February 2007: upper locations are black, while lower locations are red; main steam line C (top); main steam line D (bottom).

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Figure 3.2. Coherence between the upper and lower strain gage locations for the data collected in February 2007: main steam line A (top); main steam line B (bottom).

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Figure 3.2. Coherence between the upper and lower strain gage locations for the data collected in February 2007: main steam line C (top); main steam line D (bottom).

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This Report Does Not Contain C.D.I. Proprietary Information Table 3.3. Pressure levels for the data collected in February 2007.

(3)))

3.2 May 2006 Data Because of the failure of the lower C and D main steam line strain gages in the data collected in May 2006, symmetry of the steam lines was used as a justification for replacing these signals with those on main steam lines B and A, respectively. Geometry considerations supported this substitution with regard to both main steam line length and standpipe location.

Pressure levels are shown in Table 3.4. The main steam line data collected in May 2006 are compared with the main steam line data collected in February 2007 in Figure 3.3.

Since phasing information is lost when main steam line signals are replaced, the time signals on main steam lines C and D (from main steam lines B and A) were shifted in time increments until the maximum dryer load was achieved, as discussed in [3]. The comparison of dryer loads between May 2006 and February 2007 is presented in Section 4.

Table 3.4. Pressure levels for the data collected in May 2006.

((

(3)))

3.3 January 2007 Subscale Data Additional tests were run in January 2007 in the C.D.I. one-eighth scale test facility, in an effort to compare with the previous one-fifth scale test results and refine the flow speed at CLTP conditions [4]. These results (based on a comparison of peak PSD in the standpipes) confirmed that flow conditions run during the one-eighth scale tests, as reported in [7], were high by (( (3))).

Pressure transducer readings - taken at the same main steam line locations as in HC1 - are compared with the February 2007 data in Figure 3.4 for subscale test conditions consistent with

(( )) times the previously assumed CLTP level. Pressure levels are shown in Table 3.5.

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This Report Does Not Contain C.D.I. Proprietary Information It should be noted that the pressure measurements on main steam line D in the subscale rig exhibited a peak near a frequency of (( (3))). As a corresponding peak was not observed on any other lines or in full scale data, this peak was filtered from the pressure readings to provide a more accurate comparison of the subscale test data to plant data.

It may be seen that the average RMS pressure for the February 2007 data (from Table 3.3) is (( (3))) psid, for the May 2006 data (from Table 3.4) is (( (3))) psid, and for the January 2007 subscale data (from Table 3.5 above) is (( (3))) psid. Matching the one-eighth and one-fifth scale tests still resulted in a conservative measurement of the main steam line pressure data, even though several of the pressure locations measured similar minimum, maximum, and RMS pressure levels (comparing Table 3.3 with Table 3.5 entries).

Table 3.5. Pressure levels for the subscale test data collected in January 2007 (corrected to full scale).

(()

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Figure 3.3. Comparison of May 2006 and February 2007 main steam line data: A upper (top);

A lower (bottom).

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Figure 3.3. Comparison of May 2006 and February 2007 main steam line data: B upper (top); B lower (bottom).

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Figure 3.3. Comparison of May 2006 and February 2007 main steam line data: C upper (top); C lower (bottom). B main steam line data are substituted for C main steam line data in the May 2006 data.

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((I (3)))

Figure 3.3. Comparison of May 2006 and February 2007 main steam line data: D upper (top);

D lower (bottom). A main steam line data are substituted for D main steam line data in the May 2006 data.

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This Report Does Not Contain C.D.I. Proprietary Information Er (3)))

Figure 3.4. Comparison of January 2007 subscale test data and February 2007 main steam line data: A upper (top); A lower (bottom). The one-eighth-scale data matched the one-fifth-scale data peak PSD at the valve disc ends of the three standpipes on main steam line B [4]. ((

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[1 (3)))

Figure 3.4. Comparison of January 2007 subscale test data and February 2007 main steam line data: B upper (top); B lower (bottom). The one-eighth-scale data matched the one-fifth-scale data peak PSD at the valve disc ends of the three standpipes on main steam line B [4]. ((

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Figure 3.4. Comparison of January 2007 subscale test data and February 2007 main steam line data: C upper (top); C lower (bottom). The one-eighth-scale data matched the one-fifth-scale data peak PSD at the valve disc ends of the three standpipes on main steam line B [4]. ((

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Figure 3.4. Comparison of January 2007 subscale test data and February 2007 main steam line data: D upper (top); D lower (bottom). The one-eighth-scale data matched the one-fifth-scale data peak PSD at the valve disc ends of the three standpipes on main steam line B [4]. ((

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4. Results The three sets of main steam line pressure data were used to drive the verified acoustic circuit model (Rev. 2) for the HCI steam dome and main steam lines. Comparisons are presented on a low-resolution grid (shown schematically in [3]) by summarizing the peak and RMS pressures expected over the time interval provided in the original data, as shown in Figures 4.1 and 4.2. It may be seen that the maximum differential pressure load predicted on the HCI dryer at CLTP conditions is approximately (( (3))) psid (node 99) for the February 2007 full-scale plant data. In comparison, the May 2006 data, with use of the conservative algorithm, resulted in higher differential loads at all nodes, and a maximum differential pressure load (also at node 99) of approximately (( (3))) psid.

Peak loads are predicted on node 7 (opposite the C and D main steam lines) and node 99 (opposite the A and B main steam lines), and are compared in Figures 4.3 and 4.4. Here it may be seen that the highest PSD on the dryer occurs at a frequency of approximately (( (3))).

It may be seen that even with the favorable comparison on the standpipes between the one-fifth and one-eighth scale tests (as reported in [4]), the subscale low resolution comparison with the full scale data demonstrates a conservative prediction of the dryer loads (a maximum differential pressure load at node 7 of approximately (( (3))) psid).

(3)))

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Figure 4.1. Predicted loads at CLTP conditions as developed by the current methodology to 200 Hz, comparing full scale 2007 (red curves) with full scale 2006 (blue curves).

Node 7 is located at the back center edge of the cover plate opposite the C and D main steam lines, while node 99 is located at the back center edge of the cover plate opposite the A and B main steam lines.

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Figure 4.2. Predicted loads at CLTP conditions as developed by the current methodology to 200 Hz, comparing full scale 2007 (red curves) with subscale (black curves). Node 7 is located at the back center edge of the cover plate opposite the C and D main steam lines, while node 99 is located at the back center edge of the cover plate opposite the A and B main steam lines.

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Figure 4.3. PSD comparison of the predicted CLTP pressure. load at the center edge of the cover plate with the outer bank hood for node 7 opposite the C and D side of the dryer (top) and node 99 opposite the A-B side of the dryer (bottom), comparing full scale 2007 (red curves) with full scale 2006 (blue curves).

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Figure 4.4. PSD comparison of the predicted CLTP pressure load at the. center edge of the cover plate with the outer bank hood for node 7 opposite the C and D side of the dryer (top) and node 99 opposite the A-B side of the dryer (bottom), comparing full scale 2007 (red curves) with subscale (black curves).

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5. Conclusions The C.D.I. acoustic circuit analysis (Rev. 2), using in-plant measured data from HC I and one-eighth-scale measured data from C.D.I.:

a) Determines that steam dryer differential low-resolution loads at CLTP conditions from plant data are less than (( (3))) psid, when all strain gages are operational. The loads are lower than those predicted by the May 2006 data, and consequently the CLTP finite element analysis [8] is conservative.

b) Shows that the subscale data at CLTP conditions are conservative. The model predicts a maximum load of approximately (( (3))) psid in comparison to a maximum load of

(( (3))) psid from plant data. This comparison shows that the dryer loads predicted at EPU conditions (in [4]) should also be conservative.

c) Predicts that the loads on dryer components are largest for components nearest the main steam line inlets and decrease inward into the reactor vessel.

d) Determines that the highest differential pressure load on the dryer at full scale occurs at approximately (( (3))) Hz.

e) In-plant data indicates no discrete frequency loading is occurring, and suggests that the steam dryer loads, at least up to CLTP conditions, are a result of random flow noise. This finding is supported by the calculation of coherence between the plant upper and lower strain (3))).

gage measurements being low ((

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6. 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. 2006. Bounding Methodology to Predict Full Scale Steam Dryer Loads from In-Plant Measurements (Rev. 2). C.D.I. Report No. 05-28 (Proprietary).

3. Continuum Dynamics, Inc. 2006. Hydrodynamic Loads on Hope Creek Unit 1 Steam Dryer to 200 Hz (Rev. 2). C.D.I. Report No. 06-17.

4. Continuum Dynamics, Inc. 2007. EPU Conditions in the Main Steam Lines at Hope Creek Unit 1: Additional Subscale Four Line Tests (Rev. 0). C.D.I. Technical Note No. 07-01.

5. Structural Integrity Associates, Inc. 2007. Hope Creek Main Steam Line Strain Gage Data:

MSL Channel Combinations.

6. Structural Integrity Associates, Inc. 2006. Hope Creek Main Steam Line Strain Gage Data Reduction. Calculation File No. HC-28Q-302.

7. Continuum Dynamics, Inc. 2006. Estimating High Frequency Flow Induced Vibration in the Main Steam Lines at Hope Creek Unit 1: A Subscale Four Line Investigation of Standpipe Behavior (Rev. 1). C.D.I. Report No. 06-16.

8. Continuum Dynamics, Inc. 2006. Stress Analysis of the Hope Creek Unit 1 Steam Dryer for CLTP (Rev. 3). C.D.I. Report No. 06-24.

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