05000395/LER-1982-066, Forwards LER 82-066/03L-0.Detailed Event Analysis Encl

Forwards LER 82-066/03L-0.Detailed Event Analysis Encl

ML20083M377
Person / Time
Site:	Summer
Issue date:	01/25/1983
From:	Dixon O SOUTH CAROLINA ELECTRIC & GAS CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20083M381	List: 05000395/LER-1982-066, Forwards LER 82-066/03L-0.Detailed Event Analysis Encl 05000395/LER-1982-066-03, /03L-0:on 821226,during Mode 1 Operation,Reactor Bldg Sump Leakage Detection Sys Declared Inoperable When High Level Alarm Remained in Alarm State.Caused by Failure of Capacitance Level Detection Sys.Sys Recalibr
References
NUDOCS 8302010155
Download: ML20083M377 (3)

LER-1982-066, Forwards LER 82-066/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
3951982066R00 - NRC Website

text

4 SOUTH CAROLINA ELECTRIC & GAS COMPANY post oprics 7e4 COLuusiA. south CAROUNA 29218 O. W. DixoN. JR.

Nuc san Orsm rioNS cd'

~,

Mr. James P. O'Reilly, Director 3{;

U.S. Nuclear Regulatory Commission Region II, Suite 3100 101 Marietta Street, N.W.

Atlanta, Georgia 30303

SUBJECT:

Virgil C. Summer Nuclear '5tation Docket No. 50/395 Operating License No. NPF-12

~

Thirty Day Written Report LER 82-066

Dear Mr. O'Reilly:

Please find attached Licensee Event Report #82-066 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 the Action Statement of Technical Specification 3.4.6.1,

" Leakage Detection Systems," on December 26, 1982.

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

Ver truly yours, d

O. W.

D on, Jr.

l l

l CJM:OND:dwf Attachment I

cc:

V.

C.

Summer A.

R.

Koon T.

C. Nichols, Jr.

G.

D. Moffatt E.

C.

Roberts Site QA O. W.

Dixon, Jr.

C.

L. Ligon (NSRC)

G. J. Braddick H.

N.

Cyrus H. T. Babb J. L. Skolds D.

A.

Nauman J.

B.

Knotts, Jr.

M.

B. Whitaker, Jr.

B. A. Bursey W.

A. Williams, Jr.

I&E (Washington)

Document Management Branch O.

S. Bradham INPO Records Center R.

B. Clary NPCF M.

N. Browne File l

UPEICI AL COP'!],

8302010155 830125 Ad st A PDR ADOCK 05000395 S

PDR l

Mr. James P.

O'Reilly LER No.82-066 Page Two January 25, 1983 DETAILED DESCRIPTION OF EVENT On December 26, 1982, at 0530 hours0.00613 days <br />0.147 hours <br />8.763227e-4 weeks <br />2.01665e-4 months <br />, with the Plant in Mode 1, the Reactor Building Sump Leakage Detection System was declared inoperable when the high level alarm remained in the alarm state.

The system is required to be operable in Modes 1 through 4 per Technical Specification 3.4.6.1.b.

Normal operation continued with the inoperable leakage detection system, since the containment gaseous and particulate radiation monitoring systems were operable until December 28, 1982, when the Plant experienced a reactor trip.

On December 29, 1982, an interpretation of Technical Specification 3.4.6.1.b was agreed upon with NRC Region II, in that a one gallon per minute leak rate can be detected by probes from either the leak detection or reactor building sumps.

Reactor criticality was re-established with the alternate method of leakage detection via the reactor building sump.

PROBABLE CONSEQUENCES There were no adverse consequences from this event.

During the time period in which the leakage detection system was inoperable, the containment gaseous and particulate radiation monitoring system would have detected any increase in activity indicative of excess leakage.

CAUSE(S) OF THE OCCURRENCE The cause of the occurrence is attributed to the failure of the capacitance level detection system.

Mr. James P. O'Reilly LER No.82-066 Page Three January 25, 1983 IMMEDIATE CORRECTIVE ACTIONS TAKEN Investigation by maintenance personnel into the cause of the high alarm identified the failure of both of the level switches for the leak detection system.

The capacitance probes and associated.

electronics were replaced on December 28, 1982.

The sensitivity of the system was found to be affected by the close proximity of the probe metal support brackets during system calibration.

An engineering analysis indicated that the supports were unnecessary and were subsequently removed on December 29, 1982.

System repairs and the satisfactory performance of a calibration with the appropriate surveillance test procedure were completed on January 22, 1983, at 0600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br />.

The Reactor Building Sump Leakage Detection System was returned to service at that time as the primary means of detecting a one gallon per minute leak rate.

ACTION TAKEN TO PREVENT RECURRENCE The Licensee plans no additional action in regards to this event unless warranted by similar occurrences in the future.