ML13317B063
| ML13317B063 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 04/02/1982 |
| From: | Baskin K Southern California Edison Co |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.F.2, TASK-TM NUDOCS 8204060022 | |
| Download: ML13317B063 (1) | |
Text
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD. CALIFORNIA 91770 K. P. BASKIN TELEPHONE MANAGER OF NUCLEAR ENGINEERING, April 2, 1982 (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 NUREG-0737, II.F.2-Instrumentation for Detectio of Inadequate Core Cooling Subcooling Monitoring System San Onofre Nuclear Generating Station Unit 1
Reference:
- 1. Letter, K. P. Baskin, SCE, to D. L. Ziemann, San Onofre Unit 1 Subcooling Meter Errors, February 13, 1980
- 2. Letter, K. P. Baskin, SCE to D. L. Ziemann, NRC, Implementation of Category A Lessons Learned Requirements, April 11, 1980 Reference 1 provided information on the San Onofre Unit 1 subcooling meter/alarm errors and their sources. It also provided the justification for the use of a saturation curve as a back up for the subcooling meter.
Reference 2 described a system upgrade which would allow a greater range of temperature and pressure to be monitored and incorporate the necessary redundancy into the system.
The enclosed reactor coolant subcooling monitoring system error analysis reflects the system upgrade discussed in Reference 2 and provides a basis for the accuracy of the system. The equipment, as identified in the enclosure, has been installed and is currently inservice at San Onofre Unit 1. It should be noted that in this analysis, the Tsat and subcooling margin errors are greatly increased below 500 psi.
However, since the primary function of this system is to provide the operator with information following a small break loss-of-coolant accident (i.e., when the reactor coolant pressure will be greater than 500 psi), the existing system satisfies the intent of the subject requirement.
If you have any questions, please let me know.
Very truly yours, 83204060022 820402 PDR ADOCK 05000206 P
PDR tnclosure