ML19254F931

Responds to 791002 Request for Info Re PWR Reactor Vessel Seal Ring Missile Problem.Seal Ring Cannot Become Destructive Missile During Continued long-term Operation & Poses No Threat to Public Health & Safety

ML19254F931
Person / Time
Site:	Farley
Issue date:	11/09/1979
From:	Clayton F ALABAMA POWER CO.
To:	Schwencer A Office of Nuclear Reactor Regulation
References
TAC-11846, NUDOCS 7911190472
Download: ML19254F931 (2)

Text

Alabama Power Company

, % 600 North 18tn Street Post office Box 2641 Birmmgnam. Alabama 35291 Telephone 205 323-5341 L';#cW,";&, AlabamaPower the Southern electrC system Novenber 9,1979 Docket No. 50-348 Director of Nuclear Reactor Regulation U. S. Nuclear Regulatory Ocmnirsion Washington, D. C. 20555 Attention: Mr. A. Schwerrer Joseph M. Farley Nuclear Plant-Unit No. 1 PWR Reactor Vessel Seal Ring Missile Problem Gentlunen:

Gis letter is in response to your letter of October 2,1979 requesting information on this subject as applied to the Joseph M. Farley Nuclear Plant.

As stated in our letter of March 30, 1978, the reactor cavity seal ring is in the retracted (ra'.md) position approximately five inches above the reactor vessel flange and does not fann a seal between the vessel and the cavity during reactor operation. We have evaluated the potential post-IOCA loadings on the seal ring in this configuration and have con-cluded that the seal ring will not becrme a missile frun its retracted position.

%e evaluation was performed by determining the jet thrust forces exiting the reactor cavity in the event of a pipe break in the cavity and assuming all thrust forces are absorbed by the seal ring. % ese forces were determined based on the peak pressures in the area at the top of tlw reactor cavity as reported in Table 6.2-11 of the FSAR. Se seal ring, seal ring support, and concrete were all found capable of withstanding the applied loads without failure. Mus, the seal ring cannot becrme k T

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Docket No. 50-348 Novanber 9,1979 Director of Nuclear Reactor Begulation Attention: Mr. A. Schwencer Page a destructive missile during continued long-term operation and poses no threat to the health and safety of the public.

Yours very truly, k [ Clavb F. L. Clayton,( Jr.

FICjr/HWnnb cc: Mr. R. A. Thtxras Mr. G. F. Trowbridge 1344 043