RS-05-042, Additional Information Related to Analysis and Design of New Quad Cities Steam Dryers, and Responses to Requests for Additional Information Related to EPU Operation at Dresden and Quad Cities Nuclear Power Stations

Additional Information Related to Analysis and Design of New Quad Cities Steam Dryers, and Responses to Requests for Additional Information Related to EPU Operation at Dresden and Quad Cities Nuclear Power Stations

ML050970279
Person / Time
Site:	Dresden, Quad Cities   (DPR-019, DPR-025, DPR-029, DPR-030)
Issue date:	04/06/2005
From:	Simpson P Exelon Generation Co, Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RS-05-042
Download: ML050970279 (9)

Text

- lei t viA-A,.exE RS-05-042 April 6, 2005 U. S. Nuclear Regulatory Commission ATTN : Document Control Desk Washington, DC 20555-0001 Subject :

Additional Information Related to Analysis and Design of New Quad Cities Steam Dryers, and Responses to Requests for Additional Information Related to EPU Operation at Dresden and Quad Cities Nuclear Power Stations Reference :

Letter from Patrick R. Simpson (Exelon Generation Company, LLC) to U. S.

NRC, "Technical Documentation Related to Analysis and Design of New Quad Cities Steam Dryers, and Responses to Requests for Additional Information Related to EPU Operation at Dresden and Quad Cities Nuclear Power Stations,"

dated April 1, 2005 In the reference, Exelon Generation Company, LLC (EGC) provided information developed by General Electric (GE) in support of EGC's Integrated Steam Dryer Project. The attachment to this letter provides additional technical information from our contractor Continuum Dynamics, Inc. The attached report details the development of acoustic loads used to perform dynamic structural analysis of steam dryers.

Should you have any questions concerning this letter, please contact Mr. Thomas G. Roddey at (630) 657-2811.

Patrick R. Simpson Manager - Licensing Dresden Nuclear Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-19 and DPR-25 NRC Docket Nos. 50-237~and 50-249 Quad Cities Nuclear Power Station, Units 1 and 2 Renewed Facility Operating License Nos. DPR-29 and DPR-30 NRC Docket Nos. 50-254 and 50-265

April 6, 2005 U. S. Nuclear Regulatory Commission Page 2

Attachment:

"Quad Cities 2 New Dryer Vulnerability Loads," Revision 1, C.D.I. Technical Note No. 05-03, dated April 2005 cc :

Regional Administrator - NRC Region III NRC Senior Resident Inspector-Dresden Nuclear Power Station NRC Senior Resident Inspector - Quad Cities Nuclear Power Station

ATTACHMENT "Quad Cities 2 New Dryer Vulnerability Loads," Revision 1 C.D.I. Technical Note No. 05-03, dated April 2005

Quad Cities 2 New Dryer Vulnerability Loads Revision 1 ared under Continuum Dynamics, Inc.

34 Lexington Avenue Ewing, NJ 08618 Prepared by rchase Order No. 00077969 for

,xelon Generation LLC 4300 Winfield Road Warrenville, IL 60555 Approved by Alan J. Bilanin April 2005 C.D.I. Technical Note No. 05-03

SUMMARY

The development of a replacement steam dryer by General Electric would benefit from the loads computed from Continuum Dynamics, Inc.'s acoustic circuit methodology. These loads are determined by first predicting the acoustic sources on the existing dryer at EPU conditions, then applying these sources to the circuit model to predict loads on the new dryer. Loads obtained in this way are likely to be conservative, and offer an estimate sufficient for a structural analysis of the new dryer before installation in the plant.

DR YER DESIGNS Exelon is considering the replacement of their existing steam dryer with a new dryer suggested by General Electric (Figure 1). Table I summarizes the cross-sectional dimensions of the two dryers, where it may be seen that the new dryer eliminates the top skirt by extending the height of the dryer itself.

LOADS TRANSFER APPROACH In the absence of full-scale data on the new dryer, the loads on the existing dryer, detailed by the composite methodology described in [1], may be used to estimate the full-scale loads expected (conservatively) on the new dryer. To do so, Continuum Dynamics, Inc. examined the current solution to the existing dryer and its acoustic circuit analysis [2] and, using the CDI loads methodology (using venturi and water reference leg pressure measurements from 0 to 100 Hz and strain gage measurements from 100 to 200 Hz), extracted the four sources that exist at the inlets to the four main steam lines on the steam dome. The in-plant data used for this calculation were the measured pressure time histories at the junctions of the four main steam line venturi ment lines with the main steam lines, the measured pressure time histories at the two water reference legs, and the strain gage measurements on the B MSL at EPU conditions.

LO,4D,S COMPARISON The two dryers result in different distributions of nodes across their surfaces, but some comparison may be made by comparing the low resolution results (Figures 2a and 2b), where corner, edge, and centerline pressure loads are recovered from the detailed Helmholtz solution on both dryers.

It may be seen that the predicted loads on the new dryer are somewhat lower than the predicted loads on the existing dryer (both on peak observed load and on RNIS load). This load should bound that which occurs on the new dryer at EPU conditions.

High resolution results were sent to Exelon for structural analysis (maximum predicted load of 3.52 psid).

REFERENCES 1. (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.

C.D.I. Report No. 05-01.

2. Continuum Dynamics, Inc. 2005. Methodology to Determine Unsteady Pressure Loading on Components in Reactor Steam Domes (Rev. 5). C.D.I. Report No. 04-09 (Proprietary).

Table 1. Verified dimensions of the two steam dryers Dimension a; ao a2 1

6.0 jyvEj~jn)T?evv Dryer Q~n 151, 19.42 b

28.5 1158 C ; Ch C2 15.5 23S,8.5 d; do 1 19.0 22S,2212 e

1605 1133 f

75.0 71.5 9

137.0 161.0 h

23.0 i

88.5 88.5 166.6 166.6 120.0 120.0 125.5 125.5

I

_L_

Nominal Water level,, I I Figure 1.

Cross-sectional descriptions of the existing dryer (top) and new dryer (bottom).

Dimensions are provided in Table 1.

Figure 2a.

kl\\~IWMJ 40 60 80 100 120 140 Node Number 0

20 40 60 80 100 120 140 Node Number loads on the existing dryer as developed by the CDI methodology to 200 Hz.

V-4 Figure 2b.

2.5 0.7 0.6 0.5 0.4 0.3

---

- 1 ----- I --------- 1-1 ----- --------------------- --------

fl

--- 444- -4 50 100 Node Number 50 100 Node Number loads on the new dryer as estimated by the CDI methodology to 200 150 150