ML19224C894

From kanterella
Jump to navigation Jump to search
Responds to IE Bulletin 79-07.Action Items 2 & 4 Not Applicable.No Methods Specified in Item 1 Are Used in Leap Computer Code for Seismic Analysis of safety-related Piping
ML19224C894
Person / Time
Site: Vogtle  Southern Nuclear icon.png
Issue date: 05/24/1979
From: Staffa R
GEORGIA POWER CO.
To: James O'Reilly
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
NUDOCS 7907100173
Download: ML19224C894 (2)


Text

'

Geo g a Paer Comany 4 g

, 233 Peam ee St ed Pos! O'? ce By 4545 p

Amla Geyg a 3J3:3 0tiNRC PEC '

Te e; hor e 404 522 0060

..y . ,..,,4, Ms

, , {pgp ()g,gp Power Supply Engineering sad Services, I, , , . v . I s May 24, 1979

- f.s 4('i_

Un'ted States Nuclear Regulatory Cornission Office of Inspection and Enforcement

REFERENCE:

Region II - Suite 3100 RU: JF0 101 Marietta Street 7 50-424 Atlanta, GA 30303 50-428 Attn: Mr. James P. O'Reilly Gentlemen:

The following is submitted in response to your letter dated April 14, 1979, concerning I.E. Bulletin 79-07.

The compute code in use by the Los Angeles Power Division of Bechtel Power Corporat 7 in the seismic stress analysis of safety-related piping 4

for the Vogtle Nuclear Generating Station, Units 1.and 2, is 2101 " LEAP" (Linear Elastic Analysis of Pipe).

The following numbered responses correspond to the numbered action items contained in Bulletin 79-07.

1. None of the methods specified are used ir. the LEAP computer code for the seismic analysis of safety-related piping.
2. Not applicable.
3. The LEAP computer code is verified by computer code ME 632, TPIPE and SUPERPIPE.
4. Not applicable.

The above information applies to seismic analysis performed by Bechtel Power Corporation for safety related piping.

The following information applies to the seismic analysis performed by Westinghouse for safety related piping.

Westinghouse scope for Vogtle includes the dynamic analysis of the Reactor Coolant Loop and Class 1 auxiliary piping, The Reactor Coolant Loop will be analyzed by Westinghouse using a direct integration, three-dimensional, non-linear, time history technique using three statistically independent components of earthouake motion acting simultaneously. This 790710017s 3!g , , ,

Ja-r/yggh $

r-United States Nuclear Regulatory Cormission May 24, 1979 Page Two

. aiysis will not employ earthquake directional motions which are statis-tically dependent. The computer code which will be utilized by Westinghouse is WECAN. The Class 1 auxiliary piping will be analyzed using response spectrum modal analysis. Two perpendicular horizontal and one vertical earth-quake components will be conbined simultaneously with theThe intramodal responses intermodal response combined, using square-root-sum-of-the-squares (SRSS).

will then.be calculated using SRSS sumation of the individual modes. In no instance will an algebraic technique be used to combine the responses.

The computer code utilized by Westinghouse is WEST 0YN.

Both computer codes, WECAN and WESTDYN, are documented in WCAP-8252, Revision 1, " Documentation of Selected Westinghouse Structural Analysis Computer Codes," May 1977. Comparisons of the computer codes with bench-mark problems are also contained in the subject topical report.

Westinghouse does not employ algebraic sumation techniques for response spectrum modal analysis, and Westinghouse time history analysis techniques do not enploy earthquake directional motions which are statistica'ly dependent.

Therefore, no computer listings arc necessary for transmittal to the NRC.

Ver truly yours, f ~'. W.l ,S f'a$ctf f f a/ '

c er Qualilty Assurance Manag/

CWH:aaw xc: U. S. Nuclear Regulatory Comission Office of Inspection and Enforcement Division of Reactor Operations Inspection Washington, D.C. 20555 Mr. M. D. Hunt NRC, Region IIh 2J}}