ML20140D339

Forwards Addl Info Re 3 Volt Interim Plugging Criteria TS Amend Renewal Request,Including Determination of 2-Dimensional Pressure Distribution on Byron/Braidwood D4 SG Tube Support Plate During Mslb

ML20140D339
Person / Time
Site:	Byron, Braidwood
Issue date:	06/03/1997
From:	Hosmer J COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20140D342	List: ML20140D339 ML20140D390
References
NUDOCS 9706100354
Download: ML20140D339 (2)

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1 commonv,cahh twon company I HM Opus Pla(c Downcrs Grm c. 11.605145'*01 4

June 3,1997 U. S. Nuclear Regulatory Commission Washington, D.C. 20555 ,

Attention: Document Control Desk

Subject:

Braiduood Nuclear Power Station Unit 1 NRC Docket Numbers: 50-456 Additional Information Regarding 3 Volt Interim Plugging Criteria Technical Specification Amendment Renewal Request Rcrcrence: 1. M. D. Ly nch letter to I. Johnson dated May 14,1997, transmitting Safety i Evaluation for the Renewal of 3 Volt Interim Plugging Criteria

! 2. Teleconference dated May 19,1997, between the Commonwealth Edison Company and the Nuclear Regulatory Commission i

The Referenced letter transmitted the Nuclear Regulatory Commission (NRC) Safety Evaluation (SE) for the renewal of 3 volt interim plugging criteria for Braidwood Unit 1. In that SE the Staff stated an j Advisory Committed Reactor Safeguards (ACRS) member's concern that the effect of a two-dimensional flow distribution above the topmost tube support plate would give rise to a radial variation in the ,

I hydrodynamic picssure loading on the topmost tube support plate. As discussed in the Referenced teleconference, the Staff requested Comed's calculation uldch was performed to addressed this issue.

Atta,hed is,"A Determination of the 2-Dimensional Pressure Distribution on the Byron /Braidwood D4 SG Tube Support Plate During a MSLB." Also attached is a clarification of the reference information for this calculation.

If you have any questions concerning this correspondence, please contact Denisc Saccomanda, Senior PWR Licensing Administrator,(630)663-7283.

Sincerely, 0 ',

John B. Hosmer Engineering Vice President I

Attachment

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cc: D. Lynch, Senior Project Manager - NRR G. Dick, Byron /Braidwood Project Manager - NRR S. Burgess, Senior Resident Inspector - Byron ,

A.B. Beach, Regional Administrator - Rlli Ollice of Nuclear Safety - IDNS 9706100354 970603 PDR

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l Clarification of Reference Information for PSA B-97-05 l

Reference:

l 1)" Calculation of Byron 1/Braidwood 1 D4 Steam Generator Tube Support Plate Loads l with RELAP5M3" Comed' Document number PSA-B-95-17, Revision 0, (October 11,

! 1995) Copy of document is attached.

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2) "An Independent Verification of Byron /Braidwood D4 SG Tube Support Plate Differential Pressures During MSLB", Comed Report PSA-B-95-15, Revision 0,

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(September 1,1995) Copy of documentis attached.

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3), 5) " Nuclear Systems l", Todreas and Kaz'mi. (1990) Two sections of this l

reference are pertinent to this effort. 1) the integral Bemouill eqn of motion development on pages 351-358, and 2) the Zukauskas correlation description }

provided on page 390-391, covering flow resistance across bare rod arrays. l

4) " Introduction to Unsteady Thermofluid Mechanics", F. J. Moody .(1990) This l reference is used to discuss the isentropic expansion of the fluid page 91, and

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the acoustic propagation rates in steam water mixtures page 72. l I

6) "The Thermal Hydraulics of a Boiling Water Nuclear Reactor". R. T. Lahey and F. J.

Moody, (1977). This reference was used to provide an estimate of vessel depressurization rate independent of other computer codes. Key page is l Included in Reference 2 above (page 373). A more restrictive depressurization rate was appliedin this analysis.

7) "Braidwood Unit 1 Technical Support for Cycle 5 Steam Generator Interim Plugging l Criteria", WCAP-140146. (May,1994) This reference is the primary source of 9eometric Information. The key geometry information is shown in Figure 2.

8) " Technical Support for Afternate Plugging Criteria with Tube Expansion at TSP Intersections for Braidwood 1 and Byron 1 Model D4 Steam Generators", WCAP-14273, (1995). This document contains/ references some of the TRANFLO calculation results that are referred to with respect to depressurization rate.

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