ML13333A518
| ML13333A518 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 02/29/1980 |
| From: | Haynes J Southern California Edison Co |
| To: | Ziemann D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8003110542 | |
| Download: ML13333A518 (1) | |
Text
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD: CALIFORNIA 91770 February 29, 1980 Director of Nuclear Reactor Regulation Attention:
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 Containment Purging and Venting San Onofre Nuclear Generating Station Unit 1 By letter dated January 15, 1980 we indicated to you that we would maintain the containment vent valves at a maximum opening of 50 degrees to comply with the NRC's interim position.
In our recent shutdown the vent valves, CV10 outside containment and CV116 inside containment, were modified with the kit purchased from Fisher Controls for a 50 degree opening. Following their modification both valves were tested.
CV116 opened to 47 degrees and CV10 opened to 53.5 degrees.
It is concluded that the additional 3.5 degrees opening will not prevent CV10 from closing in the event of a design basis LOCA.
This is based on the calculation of the maximum allowable opening performed by Fisher Controls as delineated in the enclosure to our January 15, 1980 letter.
That calculation demonstrated that the valve will close from a maximum opening of 70 degrees in the event of a design basis LOCA. Therefore, remodification of CV10 is not warranted.
If you have any questions regarding this matter please let me know.
Very truly yours, 4c)3 Y J. G. Haynes Chief of Nuclear Engineering