ML13308B532
| ML13308B532 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 01/10/1975 |
| From: | Johari Moore SOUTHERN CALIFORNIA EDISON CO. |
| To: | Goller K Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8103110175 | |
| Download: ML13308B532 (2) | |
Text
Southern California Edison Company R O. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 JACK B. MOORE TEL7PON vice PREStoENT 1~~
2 3
5 7 2
- 2 2 9 2 January 10, 1975 235229 Directorate of Licensing U. S. Atomic Energy Commission Washington, D.C. 20545 Attention: Mr. Karl Goller Assistant Director for Operating R/eacto s Gentlemen:
Subject:
Flooding of Critical Equipment
.9 San Onofre Nuclear Generating Station Unit 1 As requested in your letter of December 13, 1974, we are conducting a review of San Onofre Unit 1 facilities to determine if failure of any non-seismic Category A* equipment could result in a condition, such as flooding or the release of chemicals, that might affect the performance of safety-related equipment required for safe shutdown of the facility, or that are required to limit the consequences of an accident.
Our review, to date, includes the following systems:
Service Water Domestic Water Condensate Drains Feedwater Primary Plant Makeup Auxiliary Cooling Water Screen Wash Turbine Plant Cooling Water Fire Protection Circulating Water The amount of water available from each of these systems is not sufficient to cause flooding of safety-related systems, with the exception of the circulating water system. As explained in our letter of October 5, 1972, a postulated rupture in the circulating water system could flood and overflow the condenser bay and possibly affect the performance of engineered safety systems.
- Category A is defined in Section 9.2.2 of the Final Safety Analysis Report for San Onofre Unit 1.
1/ 0175 473
Mr. Karl Goller 2 -
January 10, 1975 As committed to in our October 5, 1972 letter, we have installed a level detection system which annunciates flooding of the condenser bay in the control room. The condenser bay level detection system consists of two Magnetrol Model A-103 EP/VP level switches, mounted on two stand pipes.
One level detection unit is located at the northeast side of the condenser bay, and the other unit is located on the southwest side of the condenser bay. Either level switch will alarm in the control room.
In addition to the level detection system, we have instituted procedures which require the operator to stop the appropriate circulating water pump upon receiving an alarm from this system. These procedures coupled with the condenser bay level detection system provide assurance that the operability of engineered safety systems will not be impaired as a result of flooding.
We are continuing our review and are extending it to the effects of chemical release. No additional problem areas have been identified to date and no temporary emergency procedures have been deemed to be necessary. The results of our completed review will be submitted by February 11, 1975.
If you have any questions, please contact us.
Sincerely yours,