ML20206S234

Special Rept Spr 86-012:on 860831 & 0906,main Steam Line Process Radiation Monitor RM-G19A Declared Inoperable Due to High Reading on Monitor.Caused by Failed Auxiliary Circuit Board Inside Module Unit.Board Replaced

ML20206S234
Person / Time
Site:	Summer
Issue date:	09/11/1986
From:	Nauman D SOUTH CAROLINA ELECTRIC & GAS CO.
To:	Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
SPR-86-012, SPR-86-12, NUDOCS 8609220135
Download: ML20206S234 (2)

Text

>

,  ! $$7eI' " * " *"*

um i 29218 E"e $".s*"en "

Nuclear Operations SCE&G

- . .cm .., ,

September 11, 98g., 4g Q SO Dr. J. Nelson Grace Regional Administrator U. S. Nuclear Regulatory Commission Suite 2900 101 Marietta Street, NW Atlanta, Georgia 30323

SUBJECT:

Virgil C. Summer Nuclear Station Docket No. 50/395 Operating License No. NPF-12 Special Report (SPR 86-012)

Dear Dr. Grace:

Attached is a Special Report for the Virgil C. Summer Nuclear Station.

This Special Report is submitted pursuant to the requirements of Section 6 of the Technical Specifications.

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

CWery tru yours, kDr.'Aox ~ ~ ~

auman RJB: DAN /bjh Attachment cc: 0. W. Dixon, Jr./T. C. Nichols, Jr. K. E. Nodland E. H. Crews, Jr. R. A. Stough E. C. Roberts G. O. Percival J. G. Connelly, Jr. R. L. Prevatte W. A. Williams, Jr. J. B. Knotts, Jr.

j Group Managers S. D. Hogge l 0. S. Bradham I&E Washington D. R. Moore Document Management C. A. Price Branch W. T. Frady INP0 Records Center C. L. Ligon (NSRC) ANI Library R. M. Campbell NPCF File

$$[2gDQg$$

S I{

py- .-

I

, Dr. J. Nelson Grace g SPR 86-012 September 11, 1986 EVENT DESCRIPTION On August 31,1986, at 1015 hours0.0117 days <br />0.282 hours <br />0.00168 weeks <br />3.862075e-4 months <br />, Main Steam Line Process Radiation Monitor RM-G19A was declared inoperable due to a high reading on the l monitor that was not supported by a local survey. A Maintenance Work l Request was initiated for the repair of the unit. Health Physics was l notified of the inoperable monitor and a preplanned alternate method of I monitoring was initiated as required by Action 30, Table 3.3-6 of l Technical Specification 3.3.3, " Radiation Monitoring Instrumentation".

l The cause of the high reading was found to be due to a failed auxiliary circuit board inside of the module unit. Upon replacement of the auxiliary circuit board, RM-G19A was satisfactorily tested and declared operable September 3, 1986, at 1745 hours0.0202 days <br />0.485 hours <br />0.00289 weeks <br />6.639725e-4 months <br />. The total time inoperable was 79.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />.

l On September 6, 1986, at 0400 hours0.00463 days <br />0.111 hours <br />6.613757e-4 weeks <br />1.522e-4 months <br />, RM-G19A was again declared inoperable due to spurious high readings. A Maintenance Work Request was initiated for the repair and compensatory action was taken as required by the Technical Specifications. Upon completion of the investigation into the cause of this event by Instrument Technicians, the detector assembly was replaced. The unit was satisfactorily tested and declared operable September 9, 1986, at 0600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br />. The total time inoperable was 74 hours8.564815e-4 days <br />0.0206 hours <br />1.223545e-4 weeks <br />2.8157e-5 months <br />.

The Licensee plans no additional corrective action due to this event other than scheduled maintenance and surveillance testing.

i

-- - - _ .-. . . ..