05000295/LER-1997-004-04, :on 970221,identified Failure to Start Pump in Required Time & Led to Declaring 1C Containment Spray Inoperable.Caused by Clogged Fuel Filter & Defective components.1C Containment Spray Pump Fuel Drained & Flushed

:on 970221,identified Failure to Start Pump in Required Time & Led to Declaring 1C Containment Spray Inoperable.Caused by Clogged Fuel Filter & Defective components.1C Containment Spray Pump Fuel Drained & Flushed

ML20137E905
Person / Time
Site:	Zion File:ZionSolutions icon.png
Issue date:	03/24/1997
From:	Brennan N COMMONWEALTH EDISON CO.
To:
Shared Package
ML20137E864	List: 05000295/LER-1997-004, Forwards LER 97-004-00 Re Failure to Start Pump in Required Time & Led to Declaring 1C Containment Spray Pump Inoperable 05000295/LER-1997-004-04, :on 970221,identified Failure to Start Pump in Required Time & Led to Declaring 1C Containment Spray Inoperable.Caused by Clogged Fuel Filter & Defective components.1C Containment Spray Pump Fuel Drained & Flushed
References
LER-97-004-04, LER-97-4-4, NUDOCS 9703280296
Download: ML20137E905 (4)

LER-1997-004, on 970221,identified Failure to Start Pump in Required Time & Led to Declaring 1C Containment Spray Inoperable.Caused by Clogged Fuel Filter & Defective components.1C Containment Spray Pump Fuel Drained & Flushed

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(iv), System Actuation 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2) 10 CFR 50.73(a)(2)(1) 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown
2951997004R04 - NRC Website

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LICENSEE EVENT REPORT (LER)

FACILITY NAME DOCKET NUMBER PAGE 0l5l0l0l0l2l9l5 1l0Fl0l4 ZION NUCLEAR POWER STATION UNIT 1 1

TITLE TECHNICAL SPECIFICATION RIOUIRED REACTOR SHUTDOWN l

EVENT DATE LER NUMBER REPORT DATE OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR sE0 REV.

MONTH DAY YEAR FACILITY NAMES DOCKET NUMBER (5) l IIIIII i

t 012i 211 9

7 917 01014 1

oln 01, 214 917 I I I I I I I THis REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS Or 10 CFR $: (CHECK ONE OR MORE OF THE FOLLOWING)

OPERATING MODE 1

20.402(b) 20.405(e) 50.73(a)(2)(iv) 73.71(b)

POWER 20.405(a)(1)(1) 50 36(c)(1) 50.73(a)(2)(v) 73.71(c) 0l4l2 20.405(a)(1)(11) 50.36(c)(2) 50.73(a)(2)(vit)

OTHER (Specify in LEVEL 20.405(a)(1)(111)

X 50.73(a)(2)(1) 50.73(a)(2)(viti)(A)

Abstract below 20.405(a)(1)(tv) 50.73(a)(2)(11) 50.73(a)(2)(v111)(B) 36) 20.405(a)(1)(v) 50.73(a)(2)(111) 50.73(a)(2)(x)

LICENSEE CONTACT FOR THIS LER NAME TELEPHnNE NUMRER Neil Brennan. Regulatory Assurance Ext. 2380 slal7 vlaisl-12lnisl4 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT I

CAUSE

SYSTEM COMPONENT MANUFACTURER

CAUSE

SYSTEM COMPONENT MANUFACTURER I

I I I I II I

I I I I I l 1

1 I I l l l l l

l l 1 I I I i

SUPPLEMENTAL REPORT EXPECTED EXPECTED MONTH DAY YEAR SUBMISSION 4

M YES (If ves. complete EXPECTED SUBMISSION DATE) l NO DATE Ol5 3l0 9l7 ABSTRACT (L1mit to 1400 spaces, i.e.

approximately fifteen single-space typewritten lines).

The IC containment spray pump was taken out of service (005) for a planned maintenance work window. Upon returning the equipment to service. several problems were encountered. The initial problem, failure to start on one battery, allowed the pump to be declared operable but degraded.

Subsequent testing on February 19.1997, at 10:20 identified a failure to start the pump in the required time and led to declaring the IC containment spray pump inoperable. The Unit entered a Technical Specification Limiting l

Condition for Operation (LCO) 3.6.1.C which allows 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> for repair or commencement of shutdown. The problem I

was identified as a clogged fuel strainer. Another problem arose and was narrowed to a starting circuit relay and/or the battery starting solenoids. These components were replaced and the pump was successfully tested.

l However, the equipment was unable to be declared operable in the required LCO timeframe and the reactor was shutdown in compliance with LCO 3.6.1.0 which requires the unit be in hot shutdown within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> upon expiration of LCO 3.6.1.C.

The cause of the first event was a clogged fuel filter. The cause of the second event was defective components as identified above. However, the specific component and the cause of 4ts failure is still undn investigation and l

will be provided in a supplemental report.

j Corrective actions included cleaning the fuel strainer, performing fuel analysis replacing the starting circuit j

relay and battery starting solenoids, and successfully testing the pump.

There was minimal impact on plant safety as a result of this event.

9703280296 970324 ZLER\\97004 ler(1)

PDR ADOCK 05000295 S

PDR 1

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION FACILITV tM DOCKET NUMBER IFR NUMBER FAGE YEAR SEO REV ZION NUCLEAR POWER STATION UNIT I 0l5l0l0l0l2l9l5 9l7 0l0l4 0l0 0l2 0l4

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0F TEXT Energy Industry identification System (EIIS) codes are identified in the text as [XX)

A.

PL ANT CONDITIONS PRIOR TO EVENT Unit 1 MODE 1 - Power Oos Rx Power 42% RCS [AB] Temperature / Pressure 559 F/2235 osi.g B.

DESCRIPTION OF EVENT

Prior to the event of concern on February 19th, the 1C containment spray pump was taken out of service (005) for a planned maintenance work window on February 11. 1997.

The DOS included securing power to the pump's diesel battery chargers. On February 12.

1997, the pump work was complete and post maintenance testing was being performed.

Testing was done in accordance with Periodic Test PT-6C-ST " Containment Spray C Pump System Tests and Checks." The pump failed to start from the #2 battery but started successfully from the #1 battery when by desi n, the ratchet relay switched battery alignment. The shift reviewed Zion Operabilit Determination Manual ZODM-CS-3.3 for operability determination and concluded that he inability to start with the #2 battery did not render the pump inoperable. However. ZODM-CS-3.3 specifically states "the pum seconds.p shall be demonstrated o)erable if it achieves full running speed within five Any start time greater tlan five seconds shall be subject to System Engineering review to determine operability" during the performance of any PT-6C series procedure.

PT-6C-ST does not require timing to be performed when starting the pump. Therefore, the shift contacted System Engineering for guidance on the need to time the pump start. System Engineering responded that the requirement is satisfied by PT-6C-ST-RT

" Containment Spray C Pump System Tests and Checks" and is performed on an 18 month cycle. The shift declared the 1C containment spray pump operable, but entered the pump in the degraded equipment log (DEL) for the #2 battery 1ssue.

Engineering determined that the #2 battery was aligned to supply the various starting circuit loads during the ~20 hours of the 00S. This discharge is believed to have caused a low voltage condition which would by design cause the ratchet relay to switch to the #1 battery. The #2 battery was charced and tested successfully per PT-32

" Containment Spray / Fire Pump Battery Recorc - Monthly Quarterly Equah. ze Charge for Fire Pump Batteries.

On February 19. 1997 at 10:20 PT-6C-ST and PT-10-2 " Safeguards Actuation of Containment Spray System" were being performed because it was due and to demonstrate operability of the #2 battery to remove the pump from the DEL. There was a significant delay noticed in the start time of the pump. The engine cranked for an excessive period of time on the #2 battery and then per design switched to the #1 battery which cranked for an extended period of time and again per design switched to #2 battery at which time it started. At 12:30 the shift discussed this start time delay with System Engineering and determined that the pump was inoperable. As a consequence at 10:20 on l

February 19. 1997, the Unit entered a Technical Specification Limiting Condition for Operation (LCO) 3.6.1.C which allows 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> of continued operation to facilitate a t

repair or commencement of an orderly shutdown.

l ZLER\\97004.ler(2) l

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LICENSEE EVENT REPORT (LER) TEXT CONTINUAT10N FACILITY NAME DOCKET NUMBER lFR NUMRTR PAGF YEAR SEO PEV Zl0N NUCLEAR POWER STATION UNIT 1 0l5l0l0l0l2l9l5 9l7 0l0l4 0l0 0l3 0l4

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0F TEXT Energy Industry Identification System (Ells) codes are identified in the text as [XX]

B.

DESCRIPTION OF EVENT (Continued)

System Engineering developed a troubleshooting plan and ultimately determined that the cause of the slow start was a clogged fuel stralner. As part of the plan the fuel supply day tank was drained flushed. and refilled using a new source of fuel. The underground fuel supply tank has been isolated and remains quarantined until the investigation is complete. The pump was run for maintenance and started successfully from the #1 battery.

Operations initiated PT-6C-ST and had a successful start from the #2 battery.

However, when the pump was started from the #1 battery there was a 15-20 second delay. This delay is significantly longer than the typical 5 second delay and needed to be evalueted before declaring operability. During this delay the engine failed to respond to the start signal.

No engine cranking or relay switching occurred during the delay.

This was a distinctly different problem from the problem experienced on February 19.1997.

System Engineering developed another troubleshooting plan. A starting circuit relay was found with burnt contacts and was replaced.

The starting solenoids for both batteries were also replaced. These parts are quarantined and will be fully inspected and analyzed for potential failure modes. Operations initiated PT-6C-PT and PT-10-2 and had 5 successful starts, three on the #2 battery and two on the #1 battery. On February 21, 1997, at 13:58 the pump had been demonstrated operable. However post test lineup and verification needed to be complete prior to declaring the system operable.

It was determined that the LCO would expire 3rior to accomplishing this task. The reactor was shut down in compliance with Tec1nical Specification 3.6.1.C.

C.

CAUSE OF EVENT

This event had two failures, separate in time and in cause.

The first failure was caused by insufficient delivery of fuel to the engine.

The fuel strainer was found clogged.

The strainer was cleaned and the fuel sampled and tested.

The fuel sample met specifications.

Additionally the fuel supply day tank was drained, flushed and refilled using a new source of fuel.

The underground fuel supply tank has been isolated and remains quarantined until the investigation is complete.

The root cause of the strainer blockage is still under investigation.

The second failure to start was electrical in nature.

The apparent cause of this event was narrowed down to either a bad starting solenoid or a bad starting circuit relay. Both items were replaced and failure analysis of these components is ongoing.

ZLER\\97004.ler(3)

le ss LICENSEE EVENT REPORT (LER) TEXT CONTINUATION FACILITY M iE DOCKET N'JMBER lER NUMBfR PAGF YEAR SEO REV ZION NUCLEAR POWER STATION UNIT I 0l5l0l0l0l2l9l6 9l7 0l0l4 0l0 0l4 0l4

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0F TEXT Energy Industry Identification System (Ells) codes are identified in the text as [XX)

D.

SAFETY ANALYSIS

This event is reportable pursuant to 10 CFR 50.73(a)(2)(i)(A) which requires a 30 day report when a plant shutdown required by the Technical Specifications is completed The containment spray system is designed to reduce containment pressure and to remove iodine from the containment atmosphere. Limiting Conditions for Operation (LCO's) are established to allow for the performance of routine activities (i.e. surveillance's, tests, maintenance. etc.) during which the specified equipment could be rendered inoperable. All other equipment which is required to be operable in support of the specified LC0 was verified to be operable at the time of the event. At no time was the plant o)erating in an unanalyzed condition. Therefore, this event had minimal impact on the 'lealth and safety of the public.

E.

CORRECTIVE ACTIONS

1.

The1Ccontainmentspraypbferentsourceandthefuelstrainerwascleaned.

fuel tank was drained. flushed. refilled with bioside added fuel from a These same actions will be performed on Unit 2 prior to startup.

(29518097097901)

)

2.

System Engineering will investigate the cause of the fuel strainer clogging.

This investigation should be completed by April 30, 1997. The results of this investigation will be provided in a supplemental report.

(29518097097902) 3.

Electrical Maintenance replaced the starting circuit relay and the starting solenoids the 1C containment spray pump and operations tested the pump successfully and declared it operable.

These same actions will be performed on Unit 2 prior to startup.

(29518097097903) 4.

System Engineering will investigate the cause of the electrical start failure.

This includes the equipment failure analysis of the starting circuit relay and the starting solenolds. This investigation should be completed by April 30.1997.

The results of this investigation will be provided in a supplemental report.

(29518097097904)

F.

.P_R_EVIOUS EVENTS SEARCH AND ANALYSIS This will be provided in the supplemental report after determination of any equipment failures.

G.

COMPONENT FAILURE DATA

This will be provided in the supplemental report after determination of any equipment failures.

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?tER\\97004.ler(4)