ML13322B133
| ML13322B133 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 04/17/1990 |
| From: | Rosenblum R SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| REF-GTECI-A-47, REF-GTECI-SY, TASK-A-47, TASK-OR GL-89-19, NUDOCS 9004230461 | |
| Download: ML13322B133 (2) | |
Text
Southern California Edison Company 23 PARKER STREET IRVINE, CALIFORNIA 92718 R. M. ROSENBLUM TELEPHONE MANAGER OF
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- 4) 587-5420 NUCLEAR REGULATORY AFFAIRS April 17, 1990 U. S. Nuclear Regulatory Commission Attention:
Document Control Desk Washington, D.C.
20555 Gentlemen:
Subject:
Docket No. 50-206 Steam Generator Overfill Protection System Generic Letter 89-19 San Onofre Nuclear Generating Station Unit 1 This letter responds to the actions required by Generic Letter 89-19 regarding Unresolved Safety Issue A-47, "Safety Implications of Control Systems in LWR Nuclear Power Plants."
We have decided that a steam generator overfill protection system should be installed at San Onofre Unit 1 contingent upon the completion of the Level 1 PRA being performed on our plant.
Consideration of Unique Plant Features As indicated in the generic letter, San Onofre Unit 1 does not have a steam generator overfill protection system. As a result of our review of this issue, we have determined that the consequences of an overfill event warrant the addition of such protection. However, the unique design of SONGS 1 is such that many of the possible overfill events would be terminated by initiation of Safety Injection (SI) due to rapid RCS cool-down and depressurization. This would cause our feedwater pumps to be stopped automatically and switched to the SI function. In addition, there may be negative consequences associated with installing a high steam generator level trip on the feedwater pumps because they serve a dual function as SI pumps.
Because of these concerns we plan to perform a thorough evaluation of the benefits and risks associated with the addition of this system. If the evaluation does not support our assessment that an overfill protection system is warranted, we will supply you with the necessary information to retract this commitment. We expect to complete this portion of the PRA and be able to supply you with any necessary submittal by August 31, 1991.
If the results do not support installation of the system, we will inform you at that time.
PD ADLLL.K 650002 6
0 PF
Document Control Desk April 17, 1990 Schedule for Implementation In accordance with the schedule established in the generic letter, and as indicated on the NRC's "Order Confirming Licensee Commitments on Full-Term Operating License Open Items," this system will be implemented during the Cycle 12 refueling outage scheduled for late 1992.
The generic letter recommends that commitments made in response to the letter be implemented prior to plant start-up from the first refueling outage that begins 9 months following receipt of the letter. The letter was received by SCE on October 11, 1989.
The Cycle 11 refueling for San Onofre Unit 1 is expected to begin in late June 1990, which will be less than 9 months after SCE's receipt of the letter.
Therefore, implementation in the Cycle 12 refueling outage is consistent with the generic letter. Proposed technical specification changes will be submitted for NRC approval six months before the new system is scheduled to become operational.
If you have any questions, please let me know.
Respectfully submitted, By:
R. M. Rosenblum Manager of Nuclear Regulatory Affairs Subscribed and sworn to before me this 17th day of April, 1990 OFFICIAL SEAL S
LINDA L. RULON Notary Public-Califomia Notary Public in the State ORANGE COUNTY otayiPulic iMy Comm. Exp. Mar. 4,1992 cc:
J. B. Martin, Regional Administrator, NRC Region V C. Caldwell, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3