ML18110A895

LER 1977-012-00 for St. Lucie Unit 1, Malfunctioning of the Digital Data Processing System Resulting in a Loss of CEA Backup Position Indication

ML18110A895
Person / Time
Site:	Saint Lucie
Issue date:	03/24/1977
From:	Schmidt A Florida Power & Light Co
To:	Moseley N NRC/IE, NRC/RGN-II
References
PRN-LI-77-83 LER 1977-012-00
Download: ML18110A895 (8)

Text

U.S. NUCI.EAB REGULATORY COMMISSION DOCKET NUMOFB N RC"FORM 196

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!J I'ILE NUMOCB NlgC DISTRIBUTION roR PART ES DOCKET MATERIAL I INCXDENT REPORT TO: N.C.MOSELEY,. "ROM: FLORDIA PWR & LIGHT CO. DATE OF DOCUMENT MIAMI, FL. 3/24/77

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A.D . SCHMIDT DATE RECEIVED 4/6/77 g&LETTE R QNOTORIZED PROP INPUT FORM NUMOER OF COPIES RECEIVED

~B G IN*LI l@J NC LASS IF I E D 0 COPY DESCRIPTION ENCLOSURE LTR. TRANS THE FOLLOWXNG'...... LICENSEE EVENT REPORT FOR R.O. "/3 77-12, ON 2/24/77 CONCERNING THE DIGITAL DATA PROCESSIN SYSTEM MALFUNCTIONING...'...

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PLANT NAIVE: ST LUCIE f/ 1 SAB NOTE: XF PERSONNEL EXPOSURE IS INVOLVED SEND DXRECTLY TO KREGER/J, COLLXNS FOR ACTION/INFORMATION BRANCH CHIEF:

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P.O. BOX 013100, MIAMI, FL 33101 FLORIDA POWER & LIGHT COMPANY March 24, 1977 PRN-LI-77-83 Mr. Norman C. Moseley, Director, Region II oy.

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Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 230 Peachtree Street, N. N., Suite 1217 Atlanta, Georgia 30303

Dear Mr. Moseley:

REPORTABLE OCCURRENCE 335-77-12 ST. LUCIE UNIT 1 DATE OF OCCURRENCE: FEBRUARY 24, 1977 DIGITAL DATA PROCESSING SYSTEM The attached Licensee Event Report is being submitted in accordance with Technical Specification 6.9 to provide 30-day notification of the subject occurrence.

Very truly yours, D. Sc 3.

Vice President Power Resources MAS/cpc Attachment cc: Robert Lowenstein, Esquire Director, Office of Inspection and Enforcement (30)

Director, Office of Management Information and Program Control (3)

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PEOPLE... SERVING PEOPLE

i' LICENSEE EVENT REPORT

~ ~, I CSNTROL BLOCK: (PLEASE PAINT ALL AEOUIAEO INFORMATION) 1 UCENSEE UCENSE EVENT NAME UCENSE NUMBER TYPE TYPE Ioa~] 0 0 0 0 0 1 1 1 1 ~p 7 89

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14 15 25 26 30 31 32 REPORT AEPOAT CATEGORY TYPE SOURCE OOCKET NUMBER EVENT OATE REPORT OATE I001]CON'r 1, p p p 0 2 2 7 7 0 3 1 8 7 7 7 8 57 58 59 60 61 68 69 74 75 80 I

EVENT OESCRIPTION Qg Durin ower o eration the Di ital Data Processi S stem malfunctioned resulting in a 7 8 9 80 loss of CEA backu osition indication and the incore flux detector s stem used to I 7 89 80

~0 4 monitor incore flux distribution. Action required by Specification 3.1.3.3 and 4.2.1.3 7 8 9 80 Qg was initiated but the DDPS was restored to o eration before ower was reduced signifi-7 a9 80

~0 6 cantl and all CEA's were alread full withdrawn with all reed switch osition 7 8 9 80 SYSTEM CAUSE COMPONENT COOE

'2 COOE COMPONENT COOE MANUFACTURER

~XX ~E X X X X A F 1 2 0 7 8 9 10 11 17 43 44 47 48 CAUSE OESCRIPTION Qgaa Durin routine transfer of a ro ram from disc stora e to active memor the DDPS 80 Qg momentaril lost its reference oint. The resultin incorrect transfer caused the 7 8 9 80

. Qg co uter to al .;- No cause could be found for the s stem malfunction however F

7 89 80 FAClUTY METHOD OF STATUS =

% POWER OTHER STATUS

~ZP OISCOVEAY OISCOVERY OESCAIPTION Q~g E NA NA 7 8 9 10 12 13 44 45 46 80 FORM OF ACTIVITY COATENT AELEASEO OF RELEASE AMOUNT OF ACTNITY LOCATION OF RELEASE EH L~J Lzl NA NA 7 8 9 10 11 45 80 PERSONNEL EXPOSURES NUMBER TYPE OESCAIPTION

~s ~o o 0 z NA 7 8 9 11 12 13 PERSONNEL INJURIES NUMSEA OESCRIPTION 7

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~oo o 11 12 NA 80 PROBABLE CONSEQUENCES 7 8 9 80 LOSS OR DAMAGE TO FACILITY TYPE OESCAIPTION z NA 7 89 10 80 PUBLICITY NA 7 89 .80 AOOITIONAL FACTORS t11I w for continuation of Event Descri tion and Cause Descri tion.

7 89 80 7 89 80 M. A. Scho man PHONE 305/552-3779 CFO IIII5 ~ 1IIT

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Licensee Event Report Reportable Occurrence 335-77-12 Page 2 of 2 EVENT DESCRIPTION (Continued) indication channels operable. This is the sixth reportable occurrence involving loss of the DDPS (335-76-19, 335-76-27, 335-76-38, 335-76-48, 335-77-9), but the first occurrence due to this cause (335-77-12).

CAUSE DESCRIPTION (Continued) computer anomalies of this sort are not uncommon. Auto-restart of the unit functioned properly (after cause of halt was discovered) and the DDPS was back in service 18 minutes after the halt.

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