PNO-III-89-050, on 890801,turbine-driven Reactor Feedwater Pump B Acted Erratically When Operator Changed Level Control & Placed Pump Into Automatic.Recirculation Pump a Tripped to Permit Opening of Flow Control Valve.Cause Under Review

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PNO-III-89-050:on 890801,turbine-driven Reactor Feedwater Pump B Acted Erratically When Operator Changed Level Control & Placed Pump Into Automatic.Recirculation Pump a Tripped to Permit Opening of Flow Control Valve.Cause Under Review
ML20245J191
Person / Time
Site: LaSalle Constellation icon.png
Issue date: 08/02/1989
From: Harrison J, Shafer W
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
References
PNO-III-89-050, PNO-III-89-50, NUDOCS 8908170551
Download: ML20245J191 (2)
v • d • e


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'PRELIMI'NARYNOTIFICATIONOFEVENTORUNUSUALOCCURRENCEPNO-III-89-50DateAugust2,1989 Thisfpreliminary notification constitutes EARLY notice of events of POSSIBLE @

.safaty'or public interest significance. The information is as initially r:c::ived without verification or evaluation, and is basically all that is known by the' Region III staff on.this date.

Facility: Commonwealth Edison Co. Licensee Emergency LaSalle Unit 2 Classification:

Marseilles, IL 61341 Unusual Event Alert Docket No. 50-374 Site Area Emergency General Emergency X Not Applicable

Subject:

ERRATIC BEHAVIOR OF REACTOR FEEDWATER PUMP At 1:52 p.m. (CDT), August 1, 1989, while the reactor was operating at 98 percent power, the licensee noted that the B Turbine Driven Reactor Feedwater Pump was acting erratically.

'The.. operator had just changed level control and had just placed the A feedwater pump into automatic (the B. pump was still in manual). About 30 seconds later, the flow from the B pump increased and did not consistently respond to operator actions. The operator returned

'the A pump to manual and tripped the B pump. A motor-driven feed pump was then started to assist.in providing feedwater to the reactor. Reactor power was manually reduced to about 43 p:rcent.

During this event, the reactor water level varied between 18 inches below normal and 15 inches above normal (the reactor would have automatically scrammed if the water level had dropped to 23) inches below normal). A runback (partial closure) of the A reactor

. recirculation flow control valve also occurred causing a mismatch in flows between the two recirculation loops of greater than 10 percent.

At 2:10 p.m., the licensee entered the two-hour limiting condition for operation (LCO) to correct the mismatch or declare the A recirculation loop inoperable. At 4 p.m., the licensee tripped the A reactor recirculation pump so that the flow control valve could be opened. This terminated the two-hour clock but started the tour-hour LCO for being in a single loop operation.

At 4:05 p.m., the flow control valve was opened, the A recirculation pump restarted, and the four-hour LCO terminated. ,

The licensee is currently investigating the cause of the 8 feedwater pump problem. The runback of the A recirculation flow control valve may have been caused by a higher than normal level reset point in the runback logic.

DISTRIBUTION:

WHITE FLINT NORTH 1 MNBB REGIONS FAX TO:  !

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Chairman Carr CA AEOD R1 INPO l

~Comm. Roberts OGC ARM RII NSAC. 6 Comm. Rogers 01 OIA RIV Licensee # 4/20 Comm. Curtiss NRC Ops Ctr SECY EDO NRR NL RV MAIL T0: PDR (8/634-eg . A2 pd GPA/SLITP/PA NMSS RES DCS (Orig.)

DOT (Trans. Only) 8 ALSAP ACRS l OE Rev. 07/05/89 8908170551 890802 h$_I}h89-050 PDC c --_ - - - --_ - _ - - - _ - _ _- _-D

'PR'ELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-III-89-50 Date August 2, 1989 p , . .

The Senior Resident Inspector was in the control room during this event. A Region III.

. inspector has been sent to the site to monitor the licensee's investigation of this

' incident. A representative from NRR also is on site, t ..

4The State of Illinois will be notified.

. Region.III first learned of this event at 2:30 p.m. (CDT), August 1, 1989. This information

.is current as of 12:15 p.m. (CDT), August 2,.1989.

(A)pSAug ICONTACT: $J. Harr

@ison FTS 88-5635 W. T.afer FTS 388-656 2l89 l

____________________-___-_______-O

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