ML17353A665

LER 96-007-00:on 960329,inadvertent ESF Actuation Occurred During Refueling Outage Due to Cognitive Personnel Error. Personnel Involved Counseled & Integrated Safeguards Test Procedures Being revised.W/960429 Ltr

ML17353A665
Person / Time
Site:	Turkey Point
Issue date:	04/29/1996
From:	Hovey R, Mowrey C FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-96-106, LER-96-007, LER-96-7, NUDOCS 9605030192
Download: ML17353A665 (6)

Text

CATEGORY REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

, t ACCESSION NBR:9605030192 DOC.DATE: 96/04/29 NOTARIZED: NO DOCKET I FACIL:50-250 Turkey Point Plant, Unit 3,,Florida Power and Light C 05000250 AUTH. NAME AUTHOR AFFILIATION MOWREY,C.L. Florida Power & Light Co.

HOVEYpR.J. Florida Power & Light Co.

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 96-007-00:on 960329,inadvertent ESF actuation occurred during refueling outage due to cognitive personnel error.

Personnel involved counseled & integrated safeguards test procedures being revised.W/960429 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

TITLE: 50.73/50.9 Licensee Event Report (,LER), Incident Rpt, etc.

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-1 PD 1 1 CROTEAU,R 1 1 INTERNAL: AEOD/SPD3%B 2 2 AEOD/SPD/RRAB 1 1 TER 1 1 NRR/DE/ECGB 1 1 NRR/~EE 1 1 NRR/DE/EMEB 1 1 NRR/DRCH/HHFB 1 1 NRR/DRCH/HICB 1 1 NRR/DRCH/AOLB 1 1 NRR/DRCH/HQMB 1 1 NRR/DRPM/PECB 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 RES/DSIR/EIB 1 ~ 1 RGN2 FILE 01 1 1 EXTERNAL: L ST LOBBY WARD 1 1 LITCO BRYCE,J H 2 2 NOAC MURPHY,G.A 1 1 NOAC POOREiW. 1 1 NRC PDR 1 1 NUDOCS FULL TXT 1 1 NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTETH CONTACT THE DOCUMENT CONTROL DESK, ROOM OWFN 5D-5(EXT. 415-2083)" TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 25 ENCL 25

hPR '89 1998 L-96-106 10 CFR 50.73 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 Gentlemen:

Re: Turkey Point Units 3 & 4 Docket Nos. 50-250, 50-251 Reportable Event: 96-007 The attached Licensee Event Report 250/96-007 is being provided in accordance with 10 CFR 50.73(a)(2) (iv) .

If there are any questions, please contact us.

Very truly yours, R. J. Hovey Vice President Turkey Point Plant attachment Stewart D. Ebneter, Regional Administrator, Region II, USNRC Thomas P. Johnson, Senior Resident Inspector, Turkey Point Plant, USNRC 030032 9605030192 F60422 05000250 PDR 8

ADOCK PDR QBP+ /

an FPL Group company

LICENSEE EVENT REPORT (LER)

FACILITY HAME (1) DOCKET NUMBER (2) PAGE (3)

TURKEY POINT UNITS 3 & 4 05000250 OF 4 TITLE (4) Inadvertent Engineered Safety Features Actuation During Refueling Outage EVENT DATE (5) LER NUMBER(6) RPT DATE (7) OTHER FACILITIES INV. (8)

MOH DAY YR SEQ 4 R4 MON DAY YR FACILITY NAMES DOCKET 4 (S) 03 29 96 96 007 00 04 29 96 Turkey PoInt Unft 4 05000251 OPERATING MODE (9) 1/5 POHER LEVEL (10) 100/0 LICENSEE CONTACT FOR THIS LER (12)

TELEPHONE NUMBER C. L. Mowrey, Compliance Specialist 305-246-6204 COMPLETE ONE LINE FOR EACH CCMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFACTURER NPRDS? CAUSE SYSTEM COMPONEHT MANUFACTURER NPRDS?

SVPPLEMEHTAL REPORT EXPECTED (14) NO YES 0 EXPECTED SVBMISSI OH MONTH DATE (15)

(I! yes, complete EXPECTED SUBMISSION DATE)

ABSTRACT (16)

Test equipment was being installed in preparation for an integrated safeguards test on Florida Power & Light Company's Turkey Point Unit 4. Test potentiometers were installed that simulated a pressurizer pressure of greater than 2000 psig. This action released a Safety Injection block signal, while another Safety Injection signal was present. As a result, all available Engineered Safety Features equipment actuated, including all four Emergency Diesel Generators (two per unit), and the three high head Safety Injection pumps which were in service (3A, 3B, 4B).

Because this event affected both units, docket 05000250.

it is being reported under The cause of the event was cognitive personnel error; the test procedure required a simulated pressure of 1900 psig on each channel, which would not have unblocked the Safety Injection signal.

Personnel involved have been counseled. The integrated safeguards test procedures are being revised to provide additional barriers against this type of event.

LICENSEE ANT REPORT (LER) TEXTINTINCTION FACILITY NAME DOCKET NUMBER LER NUMBER PAGE NO.

TURKEY POINT UNITS 3 6 4 05000250/251 96-007-00 2 OF 4 I. DESCRIPTION OF THE EVENT On March 29, 1996, Florida Power & Light Company's (FPL) Turkey Point Unit 4 was in Mode 5 nearing the end of a refueling outage.

Preparations were in progress for an integrated safeguards .test, which involves starting each train of Engineered Safety Features (ESF) equipment from a simulated Safety Injection (SI) signal

[JE]. In order to perform the test, all actual SI signals must be defeated or bypassed, thereby allowing ESF equipment to respond to the simulated signal.

One of the SI actuation signals is low pressurizer [AB:pzr]

pressure (two of three channels below 1730 psig). In Mode 5, with the Reactor Coolant System [AB] depressurized, this SI signal is present, but it can be manually blocked when two out of three pressurizer pressure channels are below 2000 psig. The blocking logic also blocks the high steamline differential pressure SI signal (also present when in Mode 5). When pressure on two of three channels is above 2000 psig, the SI signals are automatically unblocked.

Pretest preparations direct that simulated 1900 psig signals be applied to all three channels. This simulated pressure is high enough to clear the low pressure SI signal, but not high enough to automatically unblock the high steamline differential pressure SI signal. In the event, Maintenance Instrumentation and Control (IGC) personnel -installed the test potentiometers with pressure signals preset at greater than 2000 psig, rather than at 1900 psig. When the test potentiometer was installed on the second channel preset at greater than 2000 psig, the SI signals were automatically unblocked. With a high steamline differential pressure SI signal still present, an ESF actuation occurred.

The signal initiated the start of the four Emergency Diesel Generators [EK:dg],and all three of the High Head SI pumps [BQ:p]

(3A, 3B, and 4B) which were operable and aligned for service.

All other equipment, which was not out of service in accordance with procedures in effect at the time, started as designed except for the 4C Emergency Containment Cooler outlet isolation valve CV-4-2908 [BK:isv], which had dual indication. An investigation determined that the valve had properly repositioned, but a position indication limit switch was improperly adjusted, resulting in the dual indication.

This inadvertent ESF actuation is being reported in accordance with 10 CFR 50.73(a)(2) (iv) . Because this event affected both units, it is being reported under docket 05000250.

LICENSEE SENT REPORT (LER) TEÃiONTINUATION FACILITY NAME DOCKET NUMBER LER NUMBER PAGE NO.

TURKEY POINT UNITS 3 & 05000250/251 96-007-00 3 OF 4 II. CAUSE OF THE EVENT The immediate cause of the ESF actuation was unblocking SI signals with an SI initiation signal present.

The intermediate cause was cognitive personnel error on the part of non-licensed utility personnel, in that they failed to follow an approved procedure. The procedure required simulated signals of 1900 psig; the simulated signals were set at greater than 2000 pslgo Root causes were a combination of instructional presentation deficiencies within the procedure, and a predisposition to believe that the procedure was adequate. These are discussed below.

The procedure cautions to perform simulations one channel at a time to avoid resetting the SI block signal. The procedure also lists the steps for installing each potentiometer, including a step to adjust each potentiometer to 1900 psig after installation. However, the steps for installing and adjusting the potentiometers are organized in the format of an independent verification sheet rather than procedural signoff steps. This method of procedural organization is typical of Operations procedures, but is in contrast to most Maintenance procedures which have specific performance steps and separate independent verification sheets. Additionally, there is no procedural guidance to verify the potentiometer settings prior to installation.

The preparation section of the procedure had been started on the previous shift, and several other preparation steps had been performed out of sequence. The success of these earlier steps, combined with the format of the procedure, predisposed the personnel to believe that successful performance did not require the substeps to be performed in sequence.

The combined result of these factors was that two potentiometers were installed, both with settings greater than 2000 psig, before either potentiometer was adjusted to 1900 psig.

III ANALYSIS,OF THE EVENT Licensing Requirements The licensing basis at Turkey Point assumes the initiation of an ESF actuation if any one of a number of set points is reached.

During preparation for the integrated safeguards test, the block relay is required to be in the block position to prevent an SI signal from reaching the logics.

LICENSEE OENT REPORT (LER) TEÃlONTINUATION FACILITY NAME DOCKET NUMBER LER NUMBER PAGE NO.

TURKEY POINT UNITS 3 & 4 05000250/251 96-007-00 Analysis of Effects on Safety Unit 4 was in Mode 5 at the time of the SI signal generation and Unit 3 was in Mode l. Although this event constitutes an unnecessary challenge to ESF equipment, and is therefore reportable, all systems in service at the time operated as expected. Given the above assessment, the health and safety of the plant personnel and general public were not compromised.

IV. CORRECTIVE ACTIONS Plant response to the SI signal was verified to be as expected, using the emergency operating procedures.

2 ~ Preparations for the integrated safeguards test were stopped until the cause of the SI signal was known and corrected.

3. The IGC personnel involved were counseled by plant management. The incident was discussed with all I&C supervisors, and at shop meetings with personnel on each shift.

4 ~ The integrated safeguards test procedures will be revised to provide additional barriers to this type of event, prior to the next refueling outage on each unit. In particular, the test preparation appendices performed by Maintenance personnel will be revised to a format consistent with Maintenance procedures.

5. Other Operations procedures involving performance by Maintenance personnel will be reviewed to determine are similar vulnerabilities created by formatting if there differences.

6~ The position indication for valve CV-4-2908 was repaired.

V. ADDITIONAL INFORMATION EIIS Codes are shown in the format [EIIS SYSTEM: IEEE component function identifier, second component function identifier (if appropriate)].

LER 250/94-002 reported an inadvertent ESF actuation while re-energizing the safeguards racks. That event was due to a failed relay.