ML13333A343
| ML13333A343 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 02/07/1979 |
| From: | Haynes J SOUTHERN CALIFORNIA EDISON CO. |
| To: | Ziemann D Office of Nuclear Reactor Regulation |
| References | |
| TASK-03-04.C, TASK-3-4.C, TASK-RR NUDOCS 7902140235 | |
| Download: ML13333A343 (1) | |
Text
Southern California Edison Company P.O. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD. CALIFORNIA 91770 February 7, 1979 Director, Office of Nuclear Reactor Regulation Attention:
Mr. D. L. Ziemann, Chief Operating Reactors Branch #2 Division of Operating Reactors U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Gentlemen:
Subject:
Docket No. 50-206, Provisional Operating License No. DPR-13 Reactor Pressure Vessel Supports, Seal Ring and Biological Shielding San Onofre Nuclear Generating Station, Unit 1 Our letter of May 4, 1978 indicated that the potential for the reactor cavity annulus seal ring or biological shielding to become a missile in the event of a LOCA pipe break inside the reactor vessel cavity would be investigated as part of the Asymmetric LOCA Loads Evaluation Program being per formed by Westinghouse. Specifically, our letter indicated this would be part of the Phase C activity, "Reactor Cavity Pressurization Studies," scheduled for completion by January 1, 1979.
The purpose of this letter is to provide you with an update of the status of our evaluation of the potential for the seal ring or biological shielding to become a missile. The status of the overall Asymmetric LOCA Loads Evaluation Program has periodically been reviewed with the NRC staff at meetings with the Westinghouse Owner's Group, the most recent meeting having been November, 1978.
The generic Reactor Cavity Pressurization Studies were completed on schedule. However, the results of these studies do not provide sufficient information to resolve the seal ring and biological shielding missile question.
Resolution of this matter is so closely related to the resolution of the overall asymmetric LOCA loads analysis, that it cannot be completed independent of the rest of the analysis. Therefore, it is our intention to incorporate resolution of this matter into the plant specific aspects of the overall Asymmetric LOCA Loads Evaluation Program. As stated in our May 4, 1978 letter, this program is scheduled to be completed by January 1, 1980. As in the past, you will be kept advised of the status of Westinghouse's analysis through periodic meetings between the NRC staff and the Westinghouse Owner's Group.
If you have any questions regarding this matter please contact me.
Very truly yours, J. G. Haynds Chief of Nuclear Engineering 47\\