LR-N07-0034, C.D.I. Technical Memorandum No. 06-23NP, Revision 1, Comparison of the Hope Creek and Quad Cities Steam Dryer Loads at EPU Conditions

C.D.I. Technical Memorandum No. 06-23NP, Revision 1, Comparison of the Hope Creek and Quad Cities Steam Dryer Loads at EPU Conditions

ML070710324
Person / Time
Site:	Hope Creek, Quad Cities
Issue date:	01/31/2007
From:	Continuum Dynamics
To:	Office of Nuclear Reactor Regulation
References
LCR H05-01, Rev 1, LR-N07-0034 C.D.I. Report 06-23NP
Download: ML070710324 (6)

Text

This Report Does Not Contain Continuum Dynamics, Inc. Proprietary Information C.D.I. Technical Memorandum No. 06-23NP Comparison of the Hope Creek and Quad Cities Steam Dryer Loads at EPU Conditions Revision 1 Prepared by Continuum Dynamics, Inc.

34 Lexington Avenue Ewing, NJ 08618 January 2007

This Report Does Not Contain Continuum Dynamics, Inc. Proprietary Information Introduction Steam flow in the main steam lines can excite oscillations in main steam line standpipes by flow induced instability over the inlet to the standpipes. These standpipes connect safety and relief valves to the main steam lines to provide pressure relief capability. Quad Cities Units I and 2 (QCI and QC2, respectively) appear to be the only domestic nuclear power plants where this excitation leads to large loads. In the Quad Cities units these oscillations - which originate in the main steam lines - propagate upstream into the steam dome and result in large steam dryer pressure loads at discrete frequencies. These loads for QC2 are now well documented (although the data remain proprietary) and are now reasonably understood (although prediction of amplitudes of these loads from first principles is not possible). A steam dryer load definition for the Hope Creek Nuclear Power Station (HC1) was developed by C.D.I. from subscale tests (Ref.

1), and the purpose of this note is to compare the measured steam dryer loads at QC2 (Ref. 2) with that measured/predicted for HCI at EPU conditions.

This memo documents a limited comparison of these data.

Quad Cities Unit 2 and Hope Creek Unit 1 Selected PSDs Shown in Figure 1 are the Power Spectral Density functions for the predicted differential pressure load on the HCI and QC2 steam dryers at EPU conditions. Nodes 7 (HCI) and 17 Rev. 1 (QC2) are on the centerline between MSL C and D at the intersection of the cover plate with the outer bank hood. Nodes 99 (HC1) and 133 (QC2) are on the centerline between MSL A and B at the intersection of the cover plate with the outer bank hood. ((

(3))) It is noted in passing that the standpipe resonant frequency for HC1 was predicted to be at 120 Hz and a peak can be seen in the PDS plots for HCI at 120 Hz.

Time histories of the pressure differences are shown in Figure 2 and Figure 3 to compare HC1 and QC2 differential pressure loads. ((

(3)))

Rev. 1 2

This Report Does Not Contain Continuum Dynamics, Inc. Proprietary Information

((I Rev. 1 (3)]

Figure 1. Comparison of PSDs of pressure difference at EPU conditions for Hope Creek Unit 1 (scaled from subscale experiments) and Quad Cities Unit 2.

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This Report Does Not Contain Continuum Dynamics, Inc. Proprietary Information HC 1: Node 7 rJ2 0.3 0.2 0.1 0

-0.1

-0.2

-0.3 Rev. 1 2.2 2.3 2.4 2.5 2.6 2.7 Time (sec) 2.8 2.9 3

((

(3)]1 Figure 2. Time histories of pressure difference across the dryer at nodes 7 (HC 1) and 17 (QC2) at EPU conditions. ((

(3)))

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This Report Does Not Contain Continuum Dynamics, Inc. Proprietary Information HC 1: Node 99 0.3 0.2 0.1 0

-0.1

-0.2

-0.3 Rev. I 2.2 2.3 2.4 2.5 2.6 2.7 Time (sec) 2.8 2.9 3

(3)))

Figure 3. Time histories of pressure difference across the dryer at nodes 99 (HC1) and 133 (QC2) at EPU conditions. ((

(3)))

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This Report Does Not Contain Continuum Dynamics, Inc. Proprietary Information Quantitative Comparison of the Loads Tabulated below is a quantitative comparison of the two loads for HC1 and QC2, based on the locations on either side of the dryer (on the outer bank hoods) where the pressure loading is maximum.

Minimum Pressure Maximum Pressure RMS (psid)

(psid)

(psid)

HC1: Node 7

-0.21 0.23 0.06

((

(3)))

HCI: Node 99

-0.27 0.23 0.07

((

1 1

1 (J)))

Rev. 1 (3))) This evaluation does not take credit for the fact that the HC1 EPU load is conservative and has been discussed elsewhere.

References

1. 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.

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.05-28P.

3. Continuum Dynamics, Inc. 2006. High and Low Frequency Steam Dryer Loads by Acoustic Circuit Methodology (Rev. 0). C.D.I. Technical Memorandum No.06-25P.

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