ML13317A558
| ML13317A558 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 03/31/1983 |
| From: | Baskin K Southern California Edison Co |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML13317A559 | List: |
| References | |
| TASK-03-05.B, TASK-3-5.B, TASK-RR NUDOCS 8304040140 | |
| Download: ML13317A558 (2) | |
Text
Southern California Edison Company (7
P. 0.
BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD. CALIFORNIA 91770 K. P. BASKIN TELEPHONE MANAGER OF NUCLEAR ENGINEERING, March 31, 1983 (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.No. 50-206 SEP Topic III-5.B, Pipe Break Outside Containment San Onofre Nuclear Generating Station Unit 1 SEP Topic III-5.B, Pipe Break Outside Containment, requires that participating utilities compare their facilities with current criteria for protection against pipe breaks outside containment. The results of Phase II of this analysis are described in the enclosed report. This report uses a "screening" approach to evaluate interactions using conservative techniques.
The result is to eliminate many interactions from further consideration while identifying those where further analysis is required to determine the impact on plant operation.
This report includes the results of the evaluation of mechanical interactions. An evaluation of electrical components for pipe whip and/or jet impingement has not been included in this report.
This evaluation will be conducted in conjunction with implementation of modifications required by 10 CFR 50, Appendix R. Integration of these two projects will more efficiently utilize SCE's resources as both projects may require rerouting or protection of certain electrical components.
This report complements the Phase I report submitted by SCE in 1973. In the Phase II report those lines which considered only critical cracks in the Phase I report have now been evaluated for full pipe break effects. In addition, the Category I portion of the auxiliary feedwater discharge lines, modified as a result of TMI, have been evaluated. Portions of the steam supply line to the turbine driven auxiliary feedwater pump, modified since the Phase I report, have been recategorized as high energy.
8304040140 830331 PDR ADOCK 05000206 P
Mr. D.
March 31, 1983 However, the effects of pipe breaks in this line have not been evaluated during this phase but will be considered if determined to be necessary during the evaluation of the effects on this line to be performed during the next phase of the analysis. The evaluation of the effects on portions of the main steam lines downstream of the air wrench valves has not been completed and will be forwarded as a supplement by June 17, 1983.
During the course of the analysis for this phase of HELBA Outside Containment, it was determined that the interactions with the structural beams described in the Phase I report submitted in 1973 should be reevaluated due to the change in the seismic criteria used in that earlier report. The result of our review of two beams evaluated for impact in the west turbine area in the Phase I report is that one beam continues to maintain structural integrity under postulated high energy break loads combined with seismic loads, while the other beam does not meet the acceptance criteria. This beam will be treated as an unresolved interaction and will be further evaluated in the Phase III analysis described below. It was also determined during our review of these beams that the remaining beams that were not specifically described in the Phase I report, but that would be involved in interactions with Phase I high energy lines should be reevaluated using current seismic criteria. An evaluation of interactions with these beams will also be included in the Phase III analysis.
Phase III of HELBA Outside Containment will further evaluate the unresolved locations identified in Phase II and the interactions with structural beams from the Phase I analysis, and recommend modifications or other actions as necessary. The need to conduct Phase III of this analysis will be determined during the Integrated Assessment. The schedule for completing any additional analysis will also be determined at that time.
If you have any questions on this report, please contact me.
Very truly yours, Enclosure