ML17353A741

LER 96-008-00:on 960521,surveillance Method for Testing Emergency Diesel Generators (EDG) Determined Inadequate. Caused by Personnel Error.All Four EDGs Rapid Start Tested & EDG Surveillance Procedures modified.W/960618 Ltr

ML17353A741
Person / Time
Site:	Turkey Point
Issue date:	06/18/1996
From:	Jim Hickey, Hovey R FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-96-149, LER-96-008, LER-96-8, NUDOCS 9606260218
Download: ML17353A741 (8)

Text

C+TEGORY j.

REGULA Y INFORMATION DISTRIBUTIO SYSTEM (RIDS)

ACCESSION NBR:9606260218 DOC.DATE: 96/06/18 NOTARIZED: NO DOCKET FACIL:50-250 Turkey Point Plant, Unit 3, Florida Power and Light C 05000250 AUTH. NAME AUTHOR AFFILIATION HICKEY,J.A. Florida Power 6 Light Co.

HOVEY,R.J. Florida Power & Light Co.

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 96-008-00:on 960521,surveillance method for testing Emergency Diesel Generators (EDG) determined inadequate.

Caused by personnel error.All four EDG rapid start tested &

EDG surveillance procedures modified.W/960618 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR Q ENCL Q SIZE: S 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 PD2-3 PD 1 1 CROTEAUIR 1 1 INTERNAL: Me 2 2 AEOD/SPD/RRAB 1 1 1 1 NRR/DE/ECGB 1 1 NRR/DE/EELB 1 1 NRR/DE/EMEB 1 1 NRR/DRCH/HHFB 1 1 NRR/DRCH/HICB 1 1 NRR/DRCH/HOLB 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 D EXTERNAL: L ST LOBBY WARD 1 1 LITCO BRYCE I J 2 2 NOAC MURPHYPG.A 1 1 NOAC POORE,W. 1 1 NRC PDR 1 1 NUDOCS FULL TXT 1 1 E

N NOTE TO ALL "RIDS" RECIPIENTS:

DOCUMENT CONTROL DESi(,

PLEASE HELP US TO REDUCE WASTE! CONTACT THE ROOM OWFN SD-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: ITTR 25 ENCL 25

JUN 18 1998 L-96-149 10 CFR 50.73 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 Gentlemen:

Re: Turkey Point Units 3 and 4 Docket Nos. 50-250 and 50-251 Reportable Event: 96-008-00 The attached Licensee Event Report, 250/96-008-00, is being provided in accordance with 10 CFR 50.73(a)(2)(i)(B).

Should there be any questions, please contact us.

r ruly yours, 4

k C J8i<~c R. J. Bovey, Vice President Turkey Point Plant JAH Attachment cc: S. D. Ebneter, Regional Administrator, Region II, USNRC T. P. Johnson, Senior Resident Inspector, USNRC, Turkey Point Plant isp .~AAA r<<LJP%J

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'P6062602i8 'rr60bi8 PDR ADOCK 05000250 S PDR an FPL Group company

J LICENSEE EVENT REPORT (LER)

FACILITY NAME (1) DOCKS. NUMBER (2) PAGE (3)

TURKEY POINT UNIT 3 05000250 1 OF 4 TITLE (() INADEQUATE SURVEILLANCE TESTING FOR EMERGENCY DIESEL GENERATORS EVENT DATE (5) LER NUMBER(6) Rl'T DATE (7) OTHER FACILITIES INV. (S)

DAY SEQ ~ FACILITY NAMES DOCKET I (S) 05 21 96 96 008 00 06 18 96 OPERATING NODE (9)

POWER LEVEL (10) 100 LICENSEE CONTACT FOR THIS LER (12)

Teie hone Number James A. Hickey, Licensing Engineer (305) 246-6668 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFACTURER NPRDS2 CAUSE SYSTEM COMPONENT HANUFACTURER NPRDST SUPPLEMENTAL REPORT EXPECTED (I() NO YES EXPECTED SUBMISSION MONTH DAY YEAR DATE (15)

(II yes, cceplete EXPECTED SUBMISSION DATE)

ABSTRACT (16)

At 1030 on May 21, 1996, based on an inquiry from a visiting inspector Florida Power 6 Light Company determined the surveillance method used for testing the Emergency Diesel Generators was inadequate. All four Emergency Diesel Generators were declared inoperable and Technical Specification 4.0.3 was entered. All four Emergency Diesel Generators were required to be tested within the next 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to verify operability.

Technical Specifications require the rapid start test to be conducted from "normal conditions". Contrary to the "normal conditions" start requirement, the initial system line-up verification required the Diesel Fuel Priming Pump to be started and fuel supply parameters verified. This action was determined to constitute inadvertent pre-conditioning and did not meet the intent of verifying the rapid start capability of the Emergency Diesel Generators.

At 0050 on May 22, 1996, Technical Specification 4.0.3 was exited following the successful rapid start testing of all four Emergency Diesel Generators.

The Emergency Diesel Generator rapid start surveillance procedures have been modified to eliminate the requirement to start the Diesel Fuel Priming Pump and verify fuel supply parameters prior to the start of an Emergency Diesel Generator for surveillance testing.

LICENSEEENT REPORT (LER) TEXT COhOVATION PACILITY NAME DOCKET NUMBER LER NUMBER PAGE NO.

TURKEY POINT UNIT 3 05000250 96-008-00 2 OF 4 I. DESCRIPTION OF THE EVENT On May 20, 1996, Condition Report 96-711 was initiated as a result of an inquiry by a visiting inspector. The inspector's concern involved the practice of depressing the Diesel Fuel Priming Pump Push-button

[EK:HS] and verifying adequate fuel system parameters during the pre-start alignment verification for Emergency Diesel Generator (EDG)

[EK:DG] surveillance testing. In accordance with plant procedures a three day due date was assigned to the Condition Report to provide an operability assessment.

At 1030 on May 21, 1996, Florida Power &. Light Company determined the surveillance method used for testing the Emergency Diesel Generators was inadequate. The practice of verifying diesel fuel system parameters constituted inadvertent pre-conditioning and had the potential to mask an unlikely set of simultaneous failures. If such a combination of problems existed, the EDG surveillance might not reveal the failure. All four Emergency Diesel Generators were declared inoperable and Technical Specification 4.0.3 was entered. All four Emergency Diesel Generators were required to be tested within the next 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to verify operability.

An On The Spot Change to the EDG rapid start surveillance procedure was approved. The requirement to depress the Diesel Fuel Priming Pump Push-button and verify adequate fuel system parameters during the pre-start alignment verification was deleted.

Approximately 14.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> later, at 0050 on May 22, 1996, rapid start surveillances on all four EDGs were completed satisfactorily and Technical Specification 4.0.3 was exited.

II. CAUSE OF THE EVENT The root cause of the event was cognitive personnel error. The Vendor technical manual for the EDGs recommends depressing the Diesel Fuel Prime Push-button prior to starting the EDG. This recommendation was not properly evaluated against the requirements for surveillance testing of the EDGs in accordance with plant Technical Specifications.

III. ANALYSIS OF THE EVENT Several other potential failures of the Unit 3 EDG fuel oil system have been reviewed to determine their potential impact on the function of the EDG and to determine if the pre-test prime could have "masked" a potential failure. Each of the potential failures are discussed below:

A large failure in the suction lines [EK:TBG] to the priming and engine driven pump [EK:P] would result in a loss of prime to both pumps. This failure would be detectable by both the pre-test prime and on a diesel start attempt. No failure is masked.

A small leak in the suction line would delay full pressurization of the fuel oil system. However, it would not impact fuel inventory in the supply headers. From discussions with'KW,

LICENSEEENT REPORT (LER) TEXT CO2OVATION FACILITY NAME DOCKET NUMBER LER NUMBER PAGE NO.

TURKEY POINT UNIT 3 05000250 96-008-00 3 OF 4 performance of the injectors would not be affected by the reduced fuel supply pressure. Therefore, there would be no discernable impact on EDG performance and no failure mechanism for the diesel.

An internal leak through either the fuel pump discharge check valve [EK:V] or the over pressure protection 65 psig check valve in the metering valve could result in a.small change in header inventory. A vacuum would form in the supply headers preventing any substantial loss in fuel oil inventory. The minor loss of fuel oil would be masked on a diesel start. However, there is no failure mechanism for the EDG and overall EDG performance would be unaffected.

An external leak in the fuel oil supply piping outside of the engine covers would be visually detectable and would be identified as part of the pre-start visual inspection of the engine or by regular operator rounds. This failure would not be masked by the priming of the system and could be more easily detected following system pressurization.

A leak on a single supply header inside of the engine covers could potentially drain the affected header. This failure would leave the other header filled. On start of the diesel, the drained header could have the potential impact of starting the diesel on half of the cylinders [EK:ENG]. While the loss of up to half of the cylinders would slow the engine ramp rate, it is expected that the supply header would fill and the EDGs would continue to meet the required 15 second acceptance criteria for speed and voltage.

This failure could be masked by the manual priming operation, but would not substantially impact EDG function Leaks on both supply headers or a single leak coupled with leak-through of a check valve could potentially drain the majority of the fuel supply header and impact the successful function of the EDG. Pre-priming the fuel supply header would mask this condition during normal functional testing. Note that with the priming pump functioning, a completely drained supply header could be filled and EDG startup completed within the acceptance criteria. In order to impact EDG function, three failures are required, a supply header leak or leaks, a check valve failure and a priming pump failure.

The Unit 4 EDGs are essentially identical to those for Unit 3 with the following exceptions:

The higher relative elevation of the Skid Tank on Unit 4 eliminates any potential for loss of prime by ensuring that the suction piping is always filled and at positive pressure due to static head. This eliminates the first two potential failures discussed for Unit 3 above.

The remainder of the potential failures discussed for Unit 3 are essentially unchanged for Unit 4. The same impacts and conclusions discussed above are applicable to Unit 4.

LICENSEE ENT REPORT (LER) TEXT CO ATION fACXLITY NAME COCKET NUMBER LER NUMBER PAGE NO.

TURKEY POINT UNIT 3 05000250 96-008-00 4 OF 4 All four EDGs were successfully tested utilizing Technical Specification 4.0.3 within the time frame allowed. No problems associated with pre-conditioning the EDGs were discovered. Therefore, the health and safety of plant personnel and the public was not affected by the inadequate surveillance practice.

This event is reportable under the requirements of 10 CFR 50.73 (a) (i) (B) .

IV. CORRECTIVE ACTIONS

1. All four EDGs were successfully rapid start tested. Testing was completed on May 22, 1996.

2. The EDG surveillance procedures have been modified to eliminate the need to depress the Diesel Fuel Priming Pump Push-button and verifying adequate fuel system parameters during the pre-start alignment verification. Completed June 14, 1996 to verify The EDG surveillance procedures have been modified proper Diesel Fuel Priming Pump shaft rotation when the EDG is started. Completed June 14, 1996.

A comprehensive surveillance procedure review was performed to identify other instances of pre-conditioning. No practices which constitute pre-conditioning were identified. Completed June 14, 1996.

V. ADDITIONAL INFORMATION In 1988, both EDGs were declared inoperable simultaneously due to one being out of service for scheduled maintenance and the other exhibiting fuel pressure higher than the acceptance criteria of 40 psi. The cause of the high fuel pressure was a dirty fuel filter. Reference LER 250-88-22.

In 1992, FPL identified a surveillance procedure deficiency which resulted in not adequately testing the primary PORV setpoints prior to placing the PORVs in service. Reference LER 250-92-008.