ML18113A443

LER 1976-017-00 for St. Lucie Unit 1, During Surveillance Test, Four Bistables Were Drifted Such That Their Trip Setpoints Were Less Conservative than Required by Tech Spec 3.3.2.1

ML18113A443
Person / Time
Site:	Saint Lucie
Issue date:	05/21/1976
From:	Schmidt A Florida Power & Light Co
To:	Moseley N NRC/IE, NRC/RGN-II
References
PRN-LI-76-125 LER 1976-017-00
Download: ML18113A443 (8)

Text

U.S. NUCLFAB REGULATORY MISSION DOCKET NUMBER Nff~ POOD 195 I2-7G) 5o-335 FILE NUMOEB NRC DISTRIBUTION FDR PART 50 DOCKET MATERIAL XNCIDENT REPORT TO: ""OM: FLORIDA POWER 8o LIGHT CO DATg OF DOCUMENT MR N C MOSELEY MIAMI, FLA A D SCHMIDT DATF RECEIVED A

LETTER ONOTOBIZED PROP INPUT FORM NUMBER OF COPIES RECEIVED Cl ORIGINAL UNC LASS IF I E D COPY DESCRIPTION ENCLOSURE LTR TRANS THE FOLLOWING.. ~ ~ ~ . LER 50-335(RO 76<<17) ON II-21-76 RE POUR BISTABLES WERE POUND TO HAVE DRIFTED WHEREBY SETPOINTS DID NOT MEET TECH SPEC" ~ ~ ~ ~ ~ ~ ~

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'RE> FLORIOA POWER L LIGHT COMPANY May 21, 1976

~g& PRN-LI-76-125 Mr. Norman C. Moseley, Director, Region II Office of Inspection. and Enforcement U. S. Nuclear. Regulatory Commission 230 Peachtree Street, N.Tht., Suite 818 Georgia 30303 'tlanta,

Dear Mr. Moseley:

N3 1976 d

'da 1hIetSAR ssc0I~'0"" t0 eoueISs10~

REPORTABLE OCCURRENCE 335-76 ae d,II1 ST.,LUCIE UNIT 1 DATE OF OCCURRENCE: APRIL 21~

1 SETPOINT DRIFT The'ttached Licensee Event Report is being submitted in accordance with Technical Specification 6.9 to provide 30-day notification of the'ubject. occurrence..

Very truly yours, D. Schmidt

~

Vice President

~

Power Resources MAS/ms

'I Attachment

'Cd Jack R. Newman, Esquire Director, Office of Inspection'and Enforcement (30)

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

4 LICENSEE EVENT REPORTS CONTROL BLOCK:

~ 03LEABE PRINT ALL REQUIRED INFORMATION) 6..

. UCKNSEE LCENSE EVENT NAME UCENSE NUMBER TYPE TYPE F L L 1 0 0 0 0 0 '

1 1 '1 1 ~03

'.7[gg89 S S 0 0 0 0

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14 15 25 26 30 31 32 REPORT REPORT CATEGORY TYPE SOUACE OQCXET NUMBER EVENT OATE AEPOAT QATE

[cD1] CON'T ~L ~L 0 5 0 0 3 3 5 0 4 2 1 7 6 0 5 2 1 7 6 7' 57 58 59 60 68 69 74 75 80 I 'et EVENT OESCRIPTION Qo g . During the initial Surveillance Test of the Engineered Safeguards Panel 7 8 9 80 (ESP), four bistables were found to have drifted .such that their trip 7 89 80

~o 4 oints.were less conservative than required by Technical Specifica-89 80 Qg tion 3.3.2.1. Two of the bistables were for Containment Pressure (201 7 8 9 80 Jog and 401) and'wo were for Steam Generator Pressure (208 and 210) . In 7 89. PASsIE 80 SYSTEM CAUSE COMPON KafT COMPONENT

, 7 8 9 10

~IB COOK COOK

~F 11 1?

3 N COMPONENT CQQE S T R U,17 SUPPLER

~N 43 44 C

MANLIFACTUAKR 5 6 0 47

. CAUSE OESCRIPTION The ori inal bistable settin s were too close to Technical Specification 7 8 9 Iaas] limits. Set oint drift then caused the trip setpoints to be less 7 89 80 Q~o . conservative than the limits. The setpoints were 'adjusted and a program 7 89. MKTHOO OF 80 FACUlY 9,

STATUS  % POWER OTHER STATUS OISCQVERY QISCQVEAY OESCAIPTIQN

~

cz 7 8,4 10 12 .13 44 45 46 N/A 80 FOAM OF

'0'1 ACTIVITY CONTENT AELEASKQ OF RELEASE AMOUNT OF ACTIVITY LOCATION OF AKLEASK

~a.'. ~z ~z N/A N/A 7 8: .9 44, 45 80 PERSONNEL EXPOSURES NUMBER TYPE OESCRIPTION

~s. ~oo o ~z N/A 7 8=9 11 12 13 PERSONNEL INJURIES NUMBEA OKSCAIPTION

~00 N/A

~~4 7 8.'9.. I 0 11 12 PROBABLE CONSEQUENCES Q~g I N/A 7 .8".9 80 LOSS OR OAMAGE TO FACIUTY TYPE OESCAIPTION,

'~z N/A 7'19 . 10 BO PUBLICITY N A ~

7 89 80 AOOITIONAL FACTORS'ee Fa e Two for continuation of Event Descri tion and Cause Description 7 89 80

7. 8.9 60 Jvl. A. Schoppman ,,',.305/552-3779

I REPORTABLE OCCURRENCE 335-76-17 LICENSEE EVENT REPORT PAGE TWO Event Descri tion (Continued) both cases, redundant 'channels were available. Containment pressure setpoints had drifted to approximately 18.35ma (allowable lower limit of 18.40ma) . Steam Generator. Pressure setpoints had drifted to approximately 11. 97ma (allowable. lower limit of 12. 00ma) . The setpoints were adjusted to be at least .04ma conservative with respect to Technical Specification limits.. This was the first reportable occurrence of setpoint drift associated with the ESP. (335-76-17)-

Cause Descri tion (Continued)

\

initiated to monitor them on- a more frequent basis to determine if component failure may have been the cause of the setpoint drift.

The results indicated that component failure or abnormal instrument drift was not the cause of the occurrence. A complete ESP functional test was satisfactorily completed on May 10, 1976.

No further corrective action is planned beyond the implementation of the .04ma conservatism described above.

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