ML20072A333
| ML20072A333 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 05/24/1983 |
| From: | Ray H SOUTHERN CALIFORNIA EDISON CO. |
| To: | Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| NUDOCS 8306100072 | |
| Download: ML20072A333 (2) | |
Text
.
u Southern California Edison Comp 59&gq;,
5CU S AN ONOFRE NUCLE AR GENER A TING STA TOON p.o. e Ox 12e S AN C LEMENTE. C A LIFORNI A 92672 b;y H. B. R AY TELEPHONE STQTION M AN AGE R (714)492-7700 May 24, 1983 g
U.S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region V 1450 Maria Lane, Suite 210 Walnut Creek, California 94596-5368 Attention:
Mr. J.
B.
Martin, Regional Administrator
Dear Sir:
Subject:
Docket Nos. 50-361 and 50-362 14-Day Follow-Up Report License Conditions 2.C.(14)a and 2.C.(12)a San Onofre Nuclear Generating Station, Units 2 and 3
Reference:
Letter, U.
B. Ray (SCE) to J.
B. Martin (NRC),
dated May 9, 1983 The referenced letter provided you with confirmation of our prompt notification, pursuant to License Condition 2.G of Facility Operating Licenses NPF-10 and NPF-15 for San Onofre Units 2 and 3, respectively, involving the Fire Protection System.
License Conditions 2.C.(14)a and 2.C.(12)a of Operating Licenses NPF-10 and NPF-15, respectively, require that SCE maintain in effect and fully implement the Fire Protection Plan as delineated in the Fire Hazards Analysis (FHA).
As identified in the referenced letter, on May 6, 1983, it was determined that contrary to the requirements of National Fire Protection Association (NFPA) Standard 72D, a single break or single ground fault in the alarm circuitry between fire detectors and the fire alarm control panel results in an alarm signal and a trouble signal.
The existing design does not, however, prevent the transmission of an alarm signal during an actual fire condition.
l 8306100072 830524
~
PDR ADOCK 05000361 S
PDR l
Ba-a s
E Mr. J. B. Martin May 24, 1983 The failure to meet the NFPA 72D Standard was due to an improper design change which inadvertently eliminated the ability to differentiate between a trouble signal and an alarm signal.
This NFPA 72D criterion was not addressed during the review of the design change.
To meet this criterion, a Design Change Package (DCP) will be prepared by June 15, 1983, to modify the circuitry such that a trouble signal and an alarm signal will be mutually exclusive.
At that time, a schedule for installation will be developed.
In the interim, SCE will continue to respond to all system signals.
Public health and safety were not affected by this event since dedicated personnel respond immediately to all signals to determine the cause.
As indicated in the referenced letter, SCE is seeking clarification of the reportability requirements for incidents such as these from NRR.
Until further clarification is received, we will continue to submit these reports pursuant to License Condition 2.G.
If there are any questions r egarding this event, please so advise.
Sincerely, itB % / D %
cc:
A.E. Chaffee (USNRC Resident Inspector, Units 2 and 3)
R.J. Pate (USNRC Resident Inspector, Units 2 and 3)
J.P. Stewart (USNRC Resident Inspector, Units 2 and 3)
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