ML20115E023

Main Steamline Break Inside Containment, Bimonthly Status Rept for Apr 1985

ML20115E023
Person / Time
Site:	Catawba
Issue date:	04/30/1985
From:	Tucker H DUKE POWER CO.
To:	Adensam E, Harold Denton Office of Nuclear Reactor Regulation
References
NUDOCS 8504190173
Download: ML20115E023 (2)

Text

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.g . . W Catawba Nuclear Station Main Steamline Break Inside Containment Bimonthly Status Report April, 1985 1

A.-' DRAIN TEST The dataJreduction of'the first-parts of the drain test (cable tray, flat surface and Reactor Coolant Pump simulation tests) have been completed and incorporated into the containment models. Resumption of the. test program commences the first week of April and'is scheduled to be completed in an approximate 2 month period. Data reduction of these edditional tests

.(free fall, additional flat surface and steam generator simulation tests) is scheduled for completion by the end of June. At that time, this reduced data will also be incorporated into the containment models where applicable.. The reduced data is comprised of drop size distribution, drop velocity and percentage of splashed / film flow obtained from tne photographs

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and high-speed movies taken during testing.

B. MULTINODE COBRA /NC CALCULATION Based on the completed drain flow tests, droplet and film flow split was evaluated for each node in the multinode model. A

-data file was developed having the drain flow, drop size-and film flow per cell from the completed test data analysis.

Two multinode calculations are currently in progress with COBRA-NC; a reference calculation'without drain flow, and the same cciculation with the drain flow data from the experiment

-inputted into the code. Since the drop size for the free fall drains have not been measured, a drop size of 0.2-inches was used in the analysis.

The preliminary results,. indicate that the= average. containment temperature for no, drains from COBRA-NC is less'than the FSAR

-limit of 327' at 300 seconds. While the average is lower than the'FSAR limit, there are hot' spots within the containment at or near-the' break node which exceeds the FSAR limit. The calculation with the drain flow modeled has preliminary results calculated out to 300 seconds in the transient and indicates that the entire containment is at Tsat at 18 psia at 300 seconds

' (approximately 225*F) while the break node is at approximately 280*F. These should be. regarded as preliminary, and Westinghouse is in the process of reviewing the results, models, input and assumptions'to Jnsure that the es3culation is correct.

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DUKE Powna COMPANY P.O. Box 33189 CHAmLOTTE. N.O. 98849 HALB.TUCKERi mm,

- .E2. April 11, 1985

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.Mr. Harold R.,Denton,. Director Office of. Nuclear Reactor Regulation U.iSD Nuclear Regulatory Commission '

-Washington, D.' C. 20555 Attention: '.Ms'. E. G. Adensam . Chief i Licensing Branch No.' 4

~ Re t . Catawba Nuc1 car Station-Docket Nos.. .50-413 and 50-414-L j ~

Dear Mr. Denton:

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-License Condition 17(b) of Facility Operating License NPF-35. requires i the submittal of bimonthly reports on the status'of the confirmatory research program of tests and analyses regarding containment response for main steamline break accidents. Attached is the second bimonthly l report.

Very truly yours, l

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Hal B. Tucker l WLH: sib Attachment I

cc: Dr. J. Nelson Grace, Regional Administrator NRC Resident Inspector l U. S. Nuclear Regulatory Consatssion Catawba Nuclear Station i

Region 11 101 Marietta Street NW, Suite 2900 Atlanta, Georgia 30323 Robert Guild, Esq.

• P. O. Box 12097 Charleston,' South Carolina 29412 Mr. Jesse L. Riley

-Carolina Environmental. Study Group 854 Henley Pisce Charlotte, North Carolina ~ 28207 Palmetto Alliance

. 2135 Devine' Street

-Columbia, South Carolina 29205 $h{/

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