ML13333A350
| ML13333A350 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 03/02/1979 |
| From: | Baskin K Southern California Edison Co |
| To: | Ziemann D Office of Nuclear Reactor Regulation |
| References | |
| TASK-05-11.A, TASK-5-11.A, TASK-RR NUDOCS 7903090272 | |
| Download: ML13333A350 (4) | |
Text
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 K. P. BASKIN TELEPHONE MANAGER, GENERATION ENGINEERING March 2, 1979 213-572-1401 Director 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:
REGULATO;Y D
Subject:
Docket 50-206 Systematic Evaluation Program San Onofre Nuclear Generating Station Unit 1 By letter dated December 21, 1978 you forwarded the docketed and site visit information your staff had assembled in their review of SEP Topic V-II.A, Requirements for Isolation of High and Low Pressure Systems.
This information was presented in a tabular format by the staff.
In addition, the isolation requirements for the ECCS, RHR, Reactor Coolant Water Cleanup and Sampling Systems were specified in your letter. It was requested that we verify the correctness of the data in the staff's table and provide any additional information.
Attached hereto is the staff prepared table, the accuracy of which has either been verified or corrected. Additional information has been provided where the table appeared to be less than complete.
With regard to the ECCS at San Onofre Unit 1 the staff has indicated in the table that there is no low pressure injection system. The determination of low pressure versus high pressure systems is not obvious from the table nor the criteria referenced.
It is requested that the details of how such a conclusion was drawn by the staff be provided to us for review and verification of its correctness.
The isolation requirements for the cleanup and sampling system as identified in your letter relate to containment isolation and not necessarily the high pressure/low pressure interface in the system. For example, at San Onofre Unit 1, high pressure/low pressure interface in the letdown system is inside containment upstream from the containment penetration. Information reflected in the attached table relates to the containment isolation of the letdown system; high pressure/low pressure isolation information is reflected in Footnote 9 of the attached table.
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0 Mr. D. L. Ziemann, Chief
-2 If you have any questions or require any additional information regarding this matter please let me know.
Very truly yours, Enclosures
PLANT:
San Onofre Evaluation of Isolation of Low Pressure Systems From Reactor Coolant System Meets-Reduncancy Testaole Location or Method or Direct Interfaces3 Isolatioq of Type Between HP/LP Check Valve Pressure Method of Criteria' Isolation Valves Valves Interface Orientation Reduction Isolation Remarks Water Cleanup System
.9.
Operator action Inlet Yes 2 FRV's & 2 Yes Inside containment 9 NA8 Orifice in control roomIhM 568767 (Discharge) manual Discharge Yes i cV & I No Inside containment HorizontalNA Operator action (Charging) check in control room (CV 304 & 5)
Seal Injection Syste' Yes 2 EHV's Yes Inside Containment NA RCP Operator action in control room 2
.No low pressure injection Injection system Accumulators No accumulators Sampling System Yes 2 CV's & 2 Yes Inside containment Throttling Normally Closed 'I Sampling lines - pressurn manual valve Closes on CIS izer liquid & steam space and reactor loops B and C.
'NUR System SuctionSide Yes 2140 No Inside containment NA NA High pressure Single drop line interlock on inboard valves other valves administratively locked out Discharge Side Yes 2M-O No Inside containment NA NA
NOTE:
- 1. PWRs only
- 2. 8WRs only
- 3. Only direct interfaces considered--service water and comocbent coolino water systems not evaluated
- 4. High pressure svst es (i.e.. control rod drive hydraulic. isolation concenser, standby liquid control.
high pressure injection. & RCIC) connected to reactor coolant pressure boundary not evaluated
- 5. Inadvertent overcressurization of makeuo tanK due to reactor cociant oumo seal leak off
- 6. Reactor water cleanue system for EWRs and CVCS or Letcown System for PRS 7.. Isolation requirements for ECCS specified in SRP 6.3 (Section ilI), for RHR system in BTP RS8 5-1 attached to SRP 5.4.7 and for water cleanup and sampling system in GDC 55
- 8. NA - Not Applicable
- 9. Letdown orifice isolation valves, CV202, 203 and 204, are located at the HP/LP interface. These valves are operated from the control room and provide isolation on an SIS signal.