ML13309B338
| ML13309B338 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 09/21/1983 |
| From: | Medford M Southern California Edison Co |
| To: | Knighton G Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML13309B339 | List: |
| References | |
| NUDOCS 8309290105 | |
| Download: ML13309B338 (3) | |
Text
-v REGULATURYIFORMATION DISTRIBUTION SYWM (RIDS)
ACCESSION NBR:8309290105 DUC.DATE: 83/09/21 NOTARIZED: NO DOCKET #
FACIL:50-361 San Onofre Nuclear Station, Unit 2, Southern Californ 05000361 50-362 San Onofre Nuclear Station, Uni.t 3, Southern Californ 05000362 AUTH.NAME AUTHOR AFFILIATION MEDFORDf.0.
Southern California Edison Co.
RECIP.NAME RECIPIENT AFFILIATION KNIGHTONG.W.
Licensing Branch.
SUBJECT:
Forwards Suppi IRev 1 to "P of Effects of PORVs on Depressurization & OHR." Rev simplifies/updates analysis by providing more detailed probabilistic treatment of automatic PURV cases.
A' DISTRIBUTION CODE: 60018 COPIES RECEIVED:LTR' ENCL
/
E:-
TITLE: Licensing Submittal: PSAR/FSAR Amdts & Related Correspondence NOTES:J Hanchett Icy PUR Documents. ELD Chandler icy.
05000361 J Hanchett Icy PUR Documents..ELD Chandler icy.
05000362 RECIPIENT CQPIES RECIPIENT COPIES TO CODE/NAME LT1R ENCL ID CODE/NAME LTTR ENCL NRH/DL/ADL 1
A NRR LB3 LA 1
ROODH.
01, 1
1 INTERNAL: ELD/HDS2 1
IE FILE 1
IE/DEPER/EPB 36 3
IE/DEPER/IRB 35 1
IE/DLQA/UAB 21 1
NRR/DE/AEAB 1
NRR/DE/CEB 11 1
NRR/DE/EHEB 1
NRR/DE/EU8 13 2
NRR/DE/GB 28 2
NRR/DE/MEB 18 1
NRR/DE/MTEB 17 1
NRR/OE/SAB 24 1
NRR/DE/SGEB 25 1
NRR/DHFS/HFE640 1
NRR/DHFS/LQB 32 1
NRR/DHFS/PSRB 1
NRR/DL/SSPB 1
NRR/DS1/AEB 26 1
NRR/DSI/ASB 1
NRR/DSI/CPB 10 1
NRR/DSI/CS8 09*
1' 1
NRR/DSI/ICSB 16 1
NRR/DSI/METB 12 1
NRR/DSI/PSB 19 1
1A8 22 1
NRR/DSI/RSU 23 1
JULE29 04*
1 1
RGNS 3
DR5DAM1/MIB 1
EXTERNAL:
ACRS 41 6
BNL(AMDTS ONLY) 1 DMB/DSS (AMDTS)
I FEMA-REP DIV 39
.1 U
LPOR 03*
1 1
NRC POR 02--
1 1
- 05.
1 1
NTIS 1
1 NOTES:
2 2
T OTAL NUMBER OF COPIES REUUIRED:
LTTR 55 ENCL 48
Southern California Edison Company P. 0.
BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD. CALIFORNIA 91770 September 21, 1983 Director, Office of Nuclear Reactor Regulation Attention::
Mr.. George W. Knighton, Branch Chief Licensing Branch No. 3 U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Gentlemen:
Subject:
Docket Nos. 50-361 and 50-362 San Onofre Nuclear Generating Station Units 2 and 3 SCE's letter of June 22, 1983 provided information in response to the NRC's questions regarding depressurization.and decay heat removal for CE plants without Power Operated Relief Valves (PORV's).
The June 22, 1983 transmittal included CEN-239, Supplement 1, "Probabilistic Risk Assessment of the Effects of PORV's on.Depressurization.and Decay Heat Removal, San Onofre Nuclear Generating Station, Units 2 and 3," dated June 1983.
CEN-239, Supplement 1 provided a probabilistic evaluation of the potential change in risks that would result from the addition of PORV's to San Onofre Unit 2 and 3. The results indicated that the addition of PORV's would have a negligible impact on core damage frequency. Specifically, that core damage frequency would decrease-by less than 1 x 10-0 per year per plant for manually actuated PORV.V;'s and that core damage frequency would increase by approximately 6.1 x 10-7 per year per plant for automatically actuated PORV's.
Subsequently., changes were made to the text of CEN-239, Supplement 1 to simplify and/or update the analysts by providi-ng a more detailed probabilistic treatment of the Automatic PORV cases and a more complete probabilistic analysis of Auxiliary Feedwater-restoration. These changes are consistent with the clarification previously provided in discussions with the NRC staff. The results.of these changes indicated that core damage frequency would decrease by approximately 1.3 X 10-7 per year per plant due to the addition of manually actuated PORV's (instead of less than 1 X 10-8) and that core damage frequency would increase by approximately 1.4 X lO-6 per year per plant due to the addition of automatically actuated PORV's (instead of 6.1 X 10-7).
8309290 1 330921 PDR ADCDQR0O6 P
Mr. G.
September 21, 1983 Enclosed please find seven (7) copies of CEN-239, Supplement 1, Revision 01, dated September 1983 which includes the changes summarized above.
Revision 01 supercedes the existing Supplement 1. The clarification provided by Revision 01 continues to support SCE's conclusion that the existing design for San Onofre Units 2 and 3 is adequate and that the addition of PORV's would have a negligible impact on core damage frequency.
If you have any questions or comments, please let me know.
Very truly yours, M. 0).
Medford Supervising Engineer San Onofre Units 2 and 3 Licensing Enclosure cc: H. Rood (Open by addressee only)
L. B. Marsh (Open by addressee only)