ML18078A692
| ML18078A692 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 01/12/1979 |
| From: | Anderson T WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| To: | Parr O Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML18078A693 | List: |
| References | |
| NS-TMA-2023, NUDOCS 7901230261 | |
| Download: ML18078A692 (2) | |
Text
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Electric Corporation Water Reactor Divisions Mr. Olan Parr, Chief Light Water Reactor Branch No. 3 Division of Project Management Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission 7920 Norfolk Avenue Bethesda, Maryland 20014
Dear Mr. Parr:
Please find enclosed:
PWR Systems Division Box 355 Pittsburgh Pennsylvania 15230 NS-TMA-2023 January 12, 1979 Ref a: NS-TMA-1996 dated 12/l /78 Ref b: NS-CE-1737 dated 3/21/78
. One (1) copy of "Fuel Grid Impact Loads fo.r Salem Unit No. 2 11 (Proprietary) as Attachment A.
One ( 1) copy of 11 Fue1 Grid Impact Loads for Sal em Un it No. 2 11 (Non-Propri eta ry) as Attachment B.
- 73.
One (1) copy of a synopsis of WCAP 9283 (Non-Proprietary) as Attachment C.
~o enclosed are:
~ One (1) copy of Application for Withholding, AW-79-04.
~
One (1) copy of Application for Withholding, AW-77-27.
c;~rhe purpose of this letter is to update and expand upon the information previously
?- *provided in the report, "Dynamic Analysis of the Reactor Coolant System for Loss-l.~of-Coolant-Accidents: Salem Nuclear Generating Station I and II" which was trans-
~~-;- mitted by Reference (a).
The i nforma ti on herein was discussed with re pres en ta ti ves
~") of Westinghouse and the NRC Core Performance Branch in a tel econ on December 21, C:) 1978.
C)
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Attachment A (proprietary) and Attachment B (non-proprietary) contain fuel grid
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load impact data which supplements the i ntormati on previously provided in
~ Reference (a).
It should be recognized that grid impact loads are calculated using conservative analytical techniques and modeling assumptions.
These con-servatisms, which have been discussed in other dockets such as the North Anna FSAR (Appendix SA, response to Question 5.71), include:
(1) break opening time for postulated p;p*e ruptures is typ-ically much longer (approximately 20 milli-seconds) than the assumed 1 millisecond break opening time; (2) internal hy-
- draulic loads inside the Are::t.or :essel, which have a significant effect upo: '\\o~'l;,,
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Page 2 NS-TMA-2023 1/12/79 cor~ grid impact loads are calculated using conservative hydro-elastic interaction methods; (3) break opening areas assumed in the analysis are much larger than the actual areas which the structure's rigidity.will permit to develop; (4) structural models are based upon conservative modeling assumption; (5) the allowable grid impact value is the lower bound 95 x 95 value; etc.
Considering these and other conservatisms, the calculated grid impact loads are higher than can be expected to occur.
It is, therefore, unnecessary to apply arbitrary factors of safety to the loads resulting from the core evaluations.
The information provided in Table.A-1 represents the grid impact loads for both seismic and blowdown forces calculated by the conservative methods described above.
As demonstrated by analyses in v/CAP-9283, 11 Integrity of the Primary Piping Systems of Westinghouse Nuclear Power Plants during Postulated Seismic Events," transmitted to the NRC by Reference (b), a seismic event will not cause a primary coolant system pipe rupture.
Therefore, the impact loads presented in Table A-1 do not require combination to assure adequate conservatism in the plant design.
For your information, a synopsis of WCAP-9283 is provided in Attachment C.
This submittal con ta ins proprietary information of *i.1esti nghouse Electric Corporation.
In conformance with the requirements of 10CFR2.790, as amended, of the Commission's regulations, we are enclosing with this submittal, an application for withholding from publfc disclosure and an affidavit.
The affidavit sets forth the basis on which the information may be withheld from public disclosure by the Committee.
- Correspondence with respect to the appli*cation for withholding should reference AW-79-04 and should be addressed to R. A. \\ileisemann, Manager, Regulatory and Legislative Affairs, Westinghouse Electric Corporation, P.O. Box 355, Pittsburgh Pennsylvania, 15230.
J. J. Mclnerney/W. T. Bogard
/keg Attachments cc:
R. J. Mattson, Chief NRC Division of Systems Safety