ML13331A868
| ML13331A868 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 04/01/1986 |
| From: | Medford M Southern California Edison Co |
| To: | Lear G Office of Nuclear Reactor Regulation |
| References | |
| 6426F, NUDOCS 8604030206 | |
| Download: ML13331A868 (3) | |
Text
REGULATORY IfFORMATION DISTRIBUTION SYST M (RIDS)
ACCESSION NBR:8604030206 DOC.DATE: 86/04/01 NOTARIZED: NO DOCKET #
FACIL:50-206 San Onofre Nuclear Station, Unit 1, Southern Californ 05000206 AUTH.NAME AUTHOR AFFILIATION MEDFORD,M.O.
Southern California Edison Co.
RECIP.NAME RECIPIENT AFFILIATION LEARG.E.
PWR Project Directorate 1
SUBJECT:
Forwards suppl to safety analysis in 851217 rev to Proposed Change 136 to Tech Specs per 10CFR50.59. Suppl supports rev in number of detectors in sphere encl bldg included in Table 3.14.3, "Fire Detection Instruments."
DISTRIBUTION CODE:
AOO6D COPIES RECEIVED: LTR ENCL _1 SIZE:
TITLE:
OR Submittal: Fire Protection NOTES:License Exp date in accordance with 10CFR2,2.109.
05000206 RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PWR-A PD1 PD 01 3
3 DUDLEY,R 1
1 INTERNAL: ADM/LFMB 1
0 ELD/HDS2 1
0 IE WHITNEYL 1
1 NRR PWR-A DIR 1
1 NRR PWR-B DIR 1
1 NRR STANG,J 07 2
2 NLI IL,J06 1
0 NRR/DHFT DIR 1
1 GEFI 04 1
1 RONS 1
1 EXTERNAL: 24X 1
1 LPDR 03 1
1 NRC PDR 02 1
1 NSIC 05 1
1 TOTAL NUMBER OF COPIES REGUIRED: LTTR 20 ENCL 17
Ip Southern California Edison Company P. 0 BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 M.O.MEDFORD TELEPHONE MANAGER. NUCLEAR LICENSING (818) 302-1749 April 1, 1986 Director, Office of Nuclear Reactor Regulation Attention: G. E. Lear, Director PWR Project Directorate No. 1 U. S. Nuclear Regulatory Commission Washington, D.C.
20555 Gentlemen:
Subject:
Docket No. 50-206 Proposed Change No. 136 Fire Protection Technical Specifications San Onofre Nuclear Generating Station Unit 1 By letter dated December 17, 1985, a revision to Proposed Change No. 136 to the Technical Specifications (submitted via Amendment Application No. 120 to Provisional Operating License No. DPR-13 dated June 8, 1984) was submitted. The purpose of this letter is to provide additional information in support of the revision to Proposed Change No. 136. Specifically, provided as an enclosure to this letter is a supplement to the previous safety analysis required by 10 CFR 50.59. This supplement addresses the revision in the number of detectors in the Sphere Enclosure Building included in Table 3.14.3, "Fire Detection Instruments."
Based on the safety analysis provided in the enclosure, it is concluded that this aspect of Proposed Change 136 does not involve an unreviewed safety question, nor does it present significant hazards considerations not described or implicit in the Final Safety Analysis, and there is reasonable assurance that the health and safety of the public will not be endangered by the proposed change.
Very truly yours, Enclosure cc:
F. R. Huey, USNRC Senior Resident Inspector 0
8604030206 86 26 PDR ADOC 5
SUPPLEMENT TO SAFETY ANALYSIS OF PROPOSED CHANGE NO. 136
- 1.
Will operation of the facility in accordance with this proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No The reduced number of detectors in the Sphere Enclosure Building shown in Table 3.14.3 will not involve a significant increase in the probability or the consequences of an accident previously evaluated.
This reduction is a result of plant modifications to replace the electrical penetrations.
The old penetrations included a metal enclosure on the outboard side of containment which contained terminal blocks for penetration cabling. The enclosure contained thermal fire detectors which monitored the rate of temperature rise of the volume contained in the enclosure. The new replacement penetrations do not include the metal enclosures.
Therefore, the thermal fire detectors would no longer be effective and have been removed.
The remaining detectors in the fire zone will provide sufficient coverage to ensure timely detection of potential fires in the area.
- 2. Will operation of the facility in accordance with the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?
Response: No Since the replacement penetrations are not enclosed, the detectors would not provide additional fire protection and their removal has been shown to be acceptable based on the ability of the existing instruments to detect a fire in the area in sufficient time to take appropriate action. Therefore, the removal of these detectors from Table 3.14.3 will not result in a new or different kind of accident that has not been previously evaluated.
- 3. Will operation of the facility in accordance with the proposed change involve a significant reduction in a margin of safety?
Response: No The margin of safety for Technical Specification 3.14 and Table 3.14.3 is provided by early detection of a fire. The thermal detectors removed from Table 3.14.3 only provided detection in the penetration enclosures. Since detection for the replacement penetrations will be adequately provided by existing detectors in the fire zone, operation of the facility will not involve a significant reduction in the margin of safety.
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