05000395/LER-1983-032, Forwards LER 83-032/03L-0.Detailed Event Analysis Encl

Forwards LER 83-032/03L-0.Detailed Event Analysis Encl

ML20023B642
Person / Time
Site:	Summer
Issue date:	04/29/1983
From:	Dixon O SOUTH CAROLINA ELECTRIC & GAS CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20023B644	List: 05000395/LER-1983-032, Forwards LER 83-032/03L-0.Detailed Event Analysis Encl 05000395/LER-1983-032-03, /03L-0:on 830331,detection Zone Nnn in Control Bldg Failed to Respond to Simulated Smoke Condition During Investigation of Alarm.Alarm Previously Received on 830329. Caused by Short in Smoke Detector.Detector Reinstalled
References
NUDOCS 8305050233
Download: ML20023B642 (2)

LER-1983-032, Forwards LER 83-032/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
3951983032R00 - NRC Website

text

-

w

~

SOUTH CAROLINA ELECTRIC & GAS COMPANY POST OFFICE 764 r,%

[IO.

COLUMBIA. SOUTH CAROLINA 29218

.:vj)

O. W. DIXON. JR.

uuc$s5 ""O,'* $r"[On.

April 29, 1983 f

'?g

' v Mr. James P. O'Reilly Regional Administrator U.S. Nuclear Regulatory Commission Region II, Suite 2900 101 Marietta Street, N.W.

Atlanta, Georgia 30303

SUBJECT:

Virgil C. Summer Nuclear Station Docket No. 50/395 Operating License No. NPF-12 Thirty Day Written Report LER 83-032

Dear Mr. O'Reilly:

Please find attached Licensee Event Report #83-032 for Virgil C.

Summer Nuclear Station.

This Thirty Day Report is required by Technical Specification 6.9.1.13.(b) as a result of entry into Action Statement (a) of Technical Specification 3.3.3.7,

" Fire Detection Instrumentation," on March 31, 1983.

Should there be any questions, please call us at your convenience.

Very truly yours, D, -

Dix,on, Jr.

,Wp. W.

CJM:OWD/dwf/fjc Attachment G.

J. Braddick cc:

V.

C.

Summer T.

C. Nichols, Jr.,/O. W.

Dixon, Jr.

J.

C. Miller E.

C.

Roberts J.

L. Skolds

(

J.

B.

Knotts, Jr.

H.

N.

Cyrus I&E (Washington)

Group / General Managers O.

S. Bradham Document Management Branch R.

B.

Clary INPO Records Center C. A.

Price NPCF A.

R.

Koon File (Lic./Eng.)

.D. A. Lavigne I~

C.

L. Ligon (NSRC) l l

8305050233 830429 l

$M ADDCM 05000395 hU w,,n.iC p C yT l

PM g&

l

~

l t

I b

Mr. James P.

O'Reilly LER No.83-032 Page Two April 29, 1983 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES On March 29, 1983, with the Plant in Mode 5, a trouble alarm was received from Zone NNN (Control Building 482') on the Integrated Fire and Security System monitor in the Control Room.

Operations personnel did not consider the alarm to be significant at the time since trouble alarms _are typically not alarm defeating for the DI-4 smoke detectors in this zone.

Operations personnel investigating the alarm on March 31, 1983, discovered that Zone NNN would not respond to a simulated smoke condition.

The zone was subsequently declared inoperable at 1130 hours0.0131 days <br />0.314 hours <br />0.00187 weeks <br />4.29965e-4 months <br /> in accordance with Action Statement (a) of Technical Specification 3.3.3.7.

The potential existed for a fire to be initially undetected during the two-day period that the alarm function of Zone NNN was inoperable.

However, the major equipment in the zone (charcoal filter plenums for the Control Room Ventilation System) was protected by an independently operating deluge sprinkler system, which would have provided protection to the vital equipment.

CAUSE AND CORRECTIVE ACTIONS

An hourly fire watch patrol was established within one (1) hour of the inoperable determination.

The cause of the zone failure was determined to be a smoke detector head, which was not fully locked into the base assembly.

A short circuit had occurred as a result j

of this, which showed the zone in a trouble condition and also prevented the detection of an actual alarm.

The detector was r

properly installed in the base assembly, and the zone returned to operable status by 1634 hours0.0189 days <br />0.454 hours <br />0.0027 weeks <br />6.21737e-4 months <br /> on March 31, 1983, upon the satisfactory performance of an Operational Test.

The licensee has been unable to determine how the smoke detector head became loose in the base assembly.

In order to prevent a i

future recurrence of this failure to recognize an inoperable condition, guidelines will be developed by May 30, 1983, which will provide direction'to plant personnel in the timely l

identification and resolution of problems that occur in the fire detection system.

l l

t