ML18110A894

LER 77-077-013 for Saint Lucie Unit 1 Regarding Momentary Power Loss from the Sups

ML18110A894
Person / Time
Site:	Saint Lucie
Issue date:	03/28/1977
From:	Schmidt A Florida Power & Light Co
To:	Moseley N NRC/RGN-II
References
PRN-LI-77-91 LER 77-013-00
Download: ML18110A894 (8)

Text

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~ U.S. NUCLL'AR REGULATORY CC ISS ION

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DOCI'FT NUMOE f3 FILE. NUMOEA DISTRIBUTION FDR PART 60 DOCl<ET MATERlAL INCXDENT REPORT

..~o: N.C.MOSELEY "ROM: FLORDIA PWR & LIGHT CO. DATE OF DOCUMENT MIAMI, FLORDIA

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A.D. SCHMIDT DATE RECEIVED h5LETTE B ORIGINAL QCOPY DESCRIPTION LTR. TRANS THE 0 NOTO R IZ E D LACLASS f'I E D I

FOLLOWING.......'NCLOSU PROP INPUT FOAM BE LICENSEE i s~~

NUMBER OF COPIES RECEIVED EVENT REPORT FOR R.O.,/I 77-13, ON 2/26/77 .CONCERNING POWER'THAT WAS LOST'FROM THE 'SUPS 1" (1P) (2P)

I 3'II3ildIL'LANT NAME: ST. LUCIE // 1

'AB NOTE: IP PERSONNEL EXPOSURE IS INVOLVED SEND DIRECTLY TO KREGER/J, COLLINS FOR ACTION/INFORMATION BRANCH CHXEF:

W 3 CYS FOR ACTXON LICE ASST~:

W CYS ACRS CYS SQ&8%88 S NT INTERNAL D IST RI BUTION NRC PDR IGE 2)

MIPC SCHROEDER/XPPOLITO HOUSTON NOVAK/CHECK GRXMES CASE BUTLER HANAUER TEDESCO/tfACCARY EISEN'HUT S'HAO VOLLMER/BUNCH KREGER/J ~ COLLXNS EXTERNAL DISTRIBUTION CONTROL NUMBER LPDR: )~A i@+~

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i)o~~ FLORIDA POWER LIGHT COMPANY 4'5 8L cn

$g~ March 28, 1977 PRN-LI-77-91

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- Mr. Norman C. Mofej.eg,~Director, Region II Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 230 Peachtree Street, N.W.,'uite 1217 AONJRtOQ~

Atlanta, Georgia 30303

Dear Mr. Moseley:

REPORTABLE OCCURRENCE 335-77-13 ST. LUCIE UNIT 1 DATE OF OCCURRENCE: FEBRUARY 26, 1977 RCS COLD LEG,TEMPERATURE 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 midt.

Vice President.

Power Resources MAS/cmp 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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HELPING BUILD FLORIDA

ICENSEE EVENT REPORT CONTROL BLOCK: t',PLEASE PAINT ALL REQUIRED INFORMATION)

UCENSEE UCENSE EVENT NAME UCENSE NUMBER TYPE TYPE g]89 F I 0 1 S 1 0 0 0 0 0 0 0 0 0 1 1 1 1 ~0

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7 14 15 25 26 30 31 32 REPORT REPORT CATEGORY TYPE SOURCE OOCKET NUMBER EVENT OATE REPORT OATE

[OD1]CON'I L I 0 5 0 0 3 3 5 0 2 2 6 7 7 0 .3 28 7 7 7 8 57, 58 59 60 61 68 69 74 75 80 EVENT OESCRIPTION Qp g During normal plant operation, power from the SUPS was momentarily lost. This resulted 89 80

[OD3] in the loss of AC power to the computer for the turbine and caused a shift from auto-7 89 80

[OD4] matic to manual control of the turbine. erator action was taken to reduce power 7 8 9 Jog re stabilized and re arations made to return the 7 8 9 80 Qo 6 turbine controls to automatic. Upon transferring to automatic control, the computer

.7 89 PRME 80 SYSTEM CAUSE COMPONENT CO MPOiVENT SUPPUER MANUFACTURER VGIATION

+0 W 1 2 0 N 7 8 9 10 11 12 17 44 47 48 CAUSE DESCRIPTION Qp 8 The RCS temperature changes were caused by Steam Flow changes which occurred while 7 8 9 80 Qp g automatically transferring turbine valve control mode. This transfer was not as smooth 7 8 9 80

~1 0 as required due to minor inaccuracies in the characteristic curves for sequential valve 7 89 FACIUTY 80 METHOO OF STATUS .4 POWER OTHER STATUS OISCOVERY OISCOVERY OESCRIPTION

~p N A A N/A 7 8 9 10 12 13 44 45 46 80 FORM OF ACTIVITY COIiITENT RELEASEO OF RELEASE AMOUNT OF ACTIVITY LOCATION OF RELEASE L~J LzJ N/A N/A 7 0 9 10 11 44 45 60 PERSONNEL EXPOSURES NUMBER TYPE OESCRIPTION PPz ~oo o ~z N/A 7 89 11 12 13 80 PERS'ONNEL INJURIES NUMBFR OESCRIPTION

[P4 ~oo o N/A 7 89 11 12 80

'PROB~LE CONSEQUENCES

'g N/A 7 8 9 80 LOSS OR OAMAGE TO FACIUTY TYPE OESCRIPTION

~16 N A 7 89 10 PUBLICITY N/A 7 8 9 ~ 80 ADDITIONAL FACTORS Q~

7 I89 See Page Two for continuation of Event and Cause Descriptions.

80 7 89 80 M. A. Schoppman 305/552-3779 PHONE GF0 bbt a IIEET

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• REPORTABLE OCCURRENCE 335-77-13 LlCENSEE EVENT REPORT PAGE T7/0 adjs If il $

EVENT DESCRIPTION (Cont) automatically began a transfer from sequential valve control to single valve control. This mode transfer resulted in a steam flow change which caused RCS cold leg temperature to exceed 542 F. Maximum temperature reached was 5/>3 F. RCS cold leg temperature was immediately reduced to less than 5l>2 F as required by Technical Specification 3.2.5.a. Upon completion of transfer to single valve control, plant conditions were stabilized and reactor power wa" returned to 99.5/.

This is the third occurrence in which cold leg temperature has exceeded 5/>2 F. The two nrevious events ( 335-77-1 and 335-77-8) occurred during turbine valve testing, but are related to this event in that all three occurrences were produced by the same cause.

Corrective action to preclude this type event will be to modify the tur-bine valve characteristic curves used in the turbine control system. Data has been taken and is being evaluated by the vendor with respect to revising the curves. Xn the interim period until the new curves are .available',

changes in the turbine control operating procedures have been made to reduce the likelihood of recurrence of this type of event (335-77-13).

CAUSE DESCRIPTION (Cont) control. and single valve control which have been set into the turbine control system.

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