ML072130429

C.D.I. Technical Memorandum No. 07-26NP, Revision 0, Comparison of Browns Ferry Unit 1 & Unit 2 Main Steam Line Strain Gage / Pressure Readings

ML072130429
Person / Time
Site:	Browns Ferry
Issue date:	07/31/2007
From:	Continuum Dynamics
To:	Office of Nuclear Reactor Regulation
References
TVA-BFN-TS-418, TVA-BFN-TS-431 07-26NP, Rev 0
Download: ML072130429 (11)

Text

ENCLOSURE 12 TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT (BFN)

UNITS 1, 2, AND 3 TECHNICAL SPECIFICATIONS (TS) CHANGES TS-431 AND TS-418 -

EXTENDED POWER UPRATE (EPU) - STEAM DRYER EVALUATIONS CDI TECHNICAL MEMORANDUM NO. 07-26NP, "COMPARISON OF BROWNS FERRY NUCLEAR UNIT 1 AND UNIT 2 MAIN STEAM LINE STRAIN GAGE/PRESSURE READINGS" (NON-PROPRIETARY VERSION)

Attached is the Non-Proprietary Version of CDI Technical Memorandum No. 07-26, "Comparison of Browns Ferry Nuclear Unit 1 and Unit 2 Main Steam Line Strain Gage/Pressure Readings."

This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information C.D.I. Technical Memorandum No. 07-26NP Comparison of Browns Ferry Nuclear Unit 1 and Unit 2 Main Steam Line Strain Gage / Pressure Readings Revision 0 Prepared by Continuum Dynamics, Inc.

34 Lexington Avenue Ewing, NJ 08618 Approved by 62--4A 15 Alan J. Bilanin Prepared by Milton E. Teske July 2007

This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Summary Strain gages on the main steam lines of Browns Ferry Nuclear Unit 1 (BFN 1) and Unit 2 (BFN2) recorded pressure levels at Current Licensed Thermal Power (CLTP). This technical memorandum compares these two data sets.

Data Reduction The main steam lines at BFN I and BFN2 were instrumented with strain gages so as to infer the pressure in the lines during power operation. The strain gages were located at the positions summarized in Table 1.

Table 1. Main steam line lengths for BFN1 and BFN2. Lengths are measured from the inside wall of the steam dome. BFN1 lengths are approximate.

Main Steam Line BFN1 and BFN2: BFN1: BFN2:

Length to First Length to Second Length to Second Strain Gage Strain Gage Strain Gage Measurement (ft) Measurement (ft) Measurement (ft)

A 9.5 41.2 38.1 B 9.5 41.2 39.8 C 9.5 41.2 39.5 D 9.5 41.2 38.2 The data sets were each 120 seconds long (taken at 2500 samples per second) and recorded the strain with 10 volts of excitation to the strain gages (recovering the signals with their background noise). The data sets are identified as shown in Table 2.

Table 2. Strain gage data sets for BFN 1 and BFN2.

Unit Data File Name BFN 1 20070608143544.txt BFN2 20061128172906.asc The strain gage signals were converted to pressures by the use of the conversion factors provided in [1] for BFN1 and in [2] for BFN2, as summarized in Tables 3 and 4.

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This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Table 3. Conversion factors from strain to pressure for BFN 1 [1]. Channels are averaged to give the average strain.

Strain to Pressure Channel Channel Channel Channel (psid~tstrain) Number Number Number Number MSL A Upper 2.997 1 2 3 4 MSL A Lower 3.027 5 6 7 8 MSL B Upper 3.034 9 10 11 12 MSL B Lower 2.993 13 14 15 16 MSL C Upper 2.912 17 18 19 20 MSL C Lower 2.962 21 22 23 24 MSL D Upper 2.959 25 26 27 28 MSL D Lower 3.007 29 30 31 32 Table 4. Conversion factors from strain to pressure for BFN2 [2]. Channels are averaged to give the average strain; blank sensors indicate that the sensor was inoperative.

Strain to Pressure Channel Channel Channel Channel (psid~tstrain) Number Number Number Number MSL A Upper 3.088 1 2 3 4 MSL A Lower 2.987 5 6 7 8 MSL B Upper 3.070 9 11 MSL B Lower 3.040 13 14 15 16 MSL C Upper 3.008 18 19 20 MSL C Lower 3.041 21 22 23 24 MSL D Upper 3.017 26 27 28 MSL D Lower 3.022 29 30 31 Exclusion frequencies were used to remove extraneous signals, as also identified for BFNI in [1] and a subsequent email, and for BFN2 in [2], and summarized in Tables 5 and 6.

The standvive excitation frequency of 218 Hz was removed in all signals.

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This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Table 5. Exclusion frequencies for BFN1 strain gage data collected with 10 volts of excitation to the strain gages, as suggested in [1] and a subsequent email. VFD = variable frequency drive.

Recirc = recirculation pumps.

Frequency Range (Hz) Exclusion Cause 0-2 Mean 59.8 - 60.2 Line Noise 119.9 - 120.1 Line Noise 179.8 - 180.2 Line Noise 239.9 - 240.1 Line Noise 50.3 - 53.0 VFD (lx) 127.0 - 128.5 Recirc Pumps A, B Speed (5x) 217.5 - 220.0 Standpipe Excitation Table 6. Exclusion frequencies for BFN2 strain gage data collected with 10 volts of excitation to the strain gages, as suggested in [2]. VFD = variable frequency drive. Recirc = recirculation pumps.

Frequency Range (Hz) Exclusion Cause 0-2 Mean 59.9 - 60.1 Line Noise 119.9 - 120.1 Line Noise 179.9 - 180.1 Line Noise 239.9 - 240.1 Line Noise 44.7-46.0 VFD (Ix) 90.8-91.0 VFD (2x) 136.1 - 136.5 VFD (3x) 181.6 - 181.8 VFD (4x) 227.1 - 227.4 VFD (5x) 112.7 - 113.2 Recirc Pump A Speed (5x) 110.4 - 111.7 Recirc Pump B Speed (5x) 218.5 - 220.0 Standpipe Excitation Data Comparison and Interpretation The filtered main steam line pressure signals may be compared by plotting their PSDs, as shown in Figures 1 to 4. Peak and RMS pressures are summarized in Table 7.

From these comparisons it may be seen that the BFN2 signals are for the most part larger than the BFN 1 signals, with the exception of the presence of a peak at 55 Hz and 75 Hz in the lower locations on main steam lines B and C (MSL B and C have the dead-headed branches).

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This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Browns Ferry CLTP: MSL A Upper 0.1 N 0.01

• C ,,

0.001 0.0001 10-5 0 50 100 150 200 250 Frequency (Hz)

Browns Ferry CLTP: MSL A Lower 0.1 N 0.01 0.001 C/)

0.4 0.0001 10-5 0 50 100 150 200 250 Frequency (Hz)

Figure 1. Comparison of BFN1 and BFN2 pressure measurements on main steam line A: upper location (top); lower location (bottom).

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This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Browns Ferry CLTP: MSL B Upper 0.1 N 0.01 Cl

• -e,,

0.001 0.0001 10-5 0 50 100 150 200 250 Frequency (Hz)

Browns Ferry CLTP: MSL B Lower 0.1 N 0.01 zl 0.001 0.0001 10-5 0 50 100 150 200 250 Frequency (Hz)

Figure 2. Comparison of BFN I and BFN2 pressure measurements on main steam line B: upper location (top); lower location (bottom).

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This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Browns Ferry CLTP: MSL C Upper 0.1 N 0.01

-o 0.001 0.0001 10-5 0 50 100 150 200 250 Frequency (Hz)

Browns Ferry CLTP: MSL C Lower 0.1 N 0.01 z0 0.001 0.0001 10-5 0 50 100 150 200 250 Frequency (Hz)

Figure 3. Comparison of BFNl and BFN2 pressure measurements on main steam line C: upper location (top); lower location (bottom).

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This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Browns Ferry CLTP: MSL D Upper 0.1 N 0.01 rA 0.001 0.0001 10-5 0 50 100 150 200 250 Frequency (Hz)

Browns Ferry CLTP: MSL D Lower 0.1 N 0.01

.5, 0.001 0.0001 10-5 0 50 100 150 200 250 Frequency (Hz)

Figure 4. Comparison of BFN1 and BFN2 pressure measurements on main steam line D: upper location (top); lower location (bottom).

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This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Table 7. Comparison of Peak and RMS values for BFN I and BFN2.

Location BFN 1 Peak BFN2 Peak BFN 1 RMS BFN2 RMS Pressure (psid) Pressure (psid) Pressure (psid) Pressure (psid)

MSL A Upper 1.925 3.417 0.454 0.568 MSL A Lower 2.144 2.422 0.504 0.546 MSL B Upper 2.145 2.198 0.510 0.519 MSL B Lower 2.374 2.817 0.551 0.538 MSL C Upper 2.643 2.624 0.588 0.584 MSL C Lower 2.866 3.650 0.633 0.650 MSL D Upper 2.098 2.888 0.473 0.627 MSL D Lower 2.410 2.613 0.481 0.573

((

(3)))1 Conclusion (3)))

References

1. Structural Integrity Associates, Inc. 2007. Browns Ferry Unit 1 Main Steam Line 100%

CLTP Strain Data Transmission. SIA Letter Report No. KKF-07-012.

2. Structural Integrity Associates, Inc. 2006. Main Steam Line 100% CLTP Strain Data Transmission. SIA Letter Report No. GSZ-06-017.

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This Document Does Not Contain Continuum Dynamics, Inc. Proprietary Information Figure 5. Predicted loads on the low-resolution grid representing BFN I (black curves) and BFN2 (red curves), as developed by the Modified Bounding Pressure acoustic circuit 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.

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