ML13317A158

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Forwards Steam Generator Integrity Considerations for San Onofre Unit 1 Following Postulated Steam & Feedline Breaks, in Response to NRC
ML13317A158
Person / Time
Site: San Onofre 
Issue date: 06/03/1982
From: Baskin K
Southern California Edison Co
To: Crutchfield D
Office of Nuclear Reactor Regulation
Shared Package
ML13317A159 List:
References
TAC-44652 NUDOCS 8206090166
Download: ML13317A158 (2)


Text

Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE

ROSEMEAD, CALIFORNIA 91770 K. P. BASKIN TELEPHONE MANAGER OF NUCLEAR ENGINEERING, (une 3,

198 213) 572-1401 SAFETY, AND LICENSING Director, Office of Nuclear Reactor Regulation Attention:

D. M. Crutchfield, Chief Operating Reactors Branch No. 5 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Gentlemen:

Subject:

Docket 50-206 Hot, Dry Steam Generator Steam Line Break Accident, Request for Additional Information San Onofre Nuclear Generating Station Unit 1 By letter dated April 20, 1982 you requested that we supplement our submittal of February 2, 1982 which provided our evaluation of the effect of adding cold auxiliary feedwater to a hot, dry steam generator. The additional information requested consisted of a fracture mechanics analysis to support our conclusions regarding the integrity of the steam generators. The purpose of this letter is to supply the requested information. consists of a report entitled, "Steam Generator Integrity Considerations for San Onofre Unit 1 Following Postulated Steam and Feedline Breaks," dated May 1982. This report provides the evaluation conducted to determine the effect of reinitiating cold auxiliary feedwater flow to the steam generators following a secondary break.

Existing conservative analyses which are bounding with respect to San Onofre Unit I were used in all but one case. These bounding analyses were conducted for standard model Westinghouse steam generators and included the transient response of the system following the break, the thermally induced stresses in the steam generators, and the fracture mechanics calculations to determine the critical flaw depth. For the case described in Section 3.5 of the report, a plant specific fracture mechanics analysis was performed since previous calculations which would bound the case were not applicable due to differences in the feedwater flow path.

The results of our conservative evaluation support the conclusions previously established which indicated that the structural integrity of the steam generators will not be adversly affected by the reinitiation of cold 8206090166 820603 PDR ADOCK 05000206 P

PDR

Mr. D.

June 3, 1982 auxiliary feedwater flow following a secondary break. The relatively low auxiliary feedwater flow which is provided to the steam generators will not cause a severe thermal shock.

If you have any questions or desire additional information, please contact me.

Very truly yours,