Information Notice 1989-08, Pump Damage Caused by Low-Flow Operation

Pump Damage Caused by Low-Flow Operation

ML031180506
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, 05000000, Zimmer, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	01/26/1989
From:	Rossi C Office of Nuclear Reactor Regulation
To:
References
IN-89-008, NUDOCS 8901190418
Download: ML031180506 (7)

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 January 26, 1989 NRC INFORMATION NOTICE NO. 89-08: PUMP DAMAGE CAUSED BY LOW-FLOW OPERATION

Addressees

All holders of operating licenses or construction permits for nuclear power

reactors.

Purpose

This information notice is being provided to alert addressees to potential

problems that may result from operation of centrifugal pumps at flows that

can cause severe pump component damage. It is expected that recipients will

review the information for applicability to their facilities and consider

actions, as appropriate, to avoid similar problems.. However, suggestions

contained in this information notice do not constitute NRC requirements;

therefore, no specific action or written response is required.

Description of Circumstances

Two events which resulted in pump damage are described below. Operations for

extended periods at low-flow conditions apparently created hydraulic instability, resulting in pump damage from cavitation, pressure pulsation, and/or vibration.

These events occurred at the Haddam Neck Plant and Susquehanna Steam Electric

Station, Unit 1 (Susquehanna 1). The pump damage at the Haddam Neck plant was

attributed to pressure pulsation and pump vibration, while at Susquehanna 1 it

was the result of cavitation.

Haddam Neck Plant Event:

On February 4, 1988, an electric-driven fire pump was declared inoperable

during a routine surveillance test when a high-amperage condition was noted.

The normal indication of 200 amps initially increased to between 340 and 360

amps. The indication further increased to 1000 amps during a subsequent

manual restart. The cause of the high amperage was attributed to physical

damage to the stuffing box brass bushing in the upper shaft area. On the

basis of the licensee's evaluation and its discussions with the manufacturer, the licepsee concluded that prolonged operation of the pump at low flow may

have caused the problem. Operation of the pump at or near the shut-off head

had occurred during the containment integrated leak rate test. During the

test, the fire pump operated in a low-flow mode, providing cooling water to

the air compressors.

8901190418 Zfr 1= -/ /C

AS_

-IN89-08 January 26, 1989 Susquehanna 1 Event:

While the plant was operating at full power on May 22, 1986, an over-current

alarm for an emergency service water (ESW) pump was received in the control

room. The pump was declared inoperable, placing the plant in a limiting

condition for operation. Subsequent disassembly of the pump revealed that

the bottom portion of the pump suction bell had separated from the pump body

and fallen into the pump pit. In addition, the pump's impeller vanes were

eroded through. Similar, but less severe, damage was found on the three

other ESW pumps. A subsequent inspection of the residual heat removal

service water (RHRSW) pumps found similar damage. The licensee determined

that the damage to the ESW and RHRSW pumps was caused by recirculation

cavitation, caused by operation of the pumps at flows significantly below

their design flow rates.

The ESW pumps are normally operated at 60 percent or less of their design flow

of approximately 6,000 gallons per minute (gpm) per pump. When the loop sup- plying cooling water to the diesels is run with two operating pumps, each pump

delivers approximately 3500 to 3900 gpm. The other loop, that does not serve

the diesels is normally run with only one pump providing approximately 1000

to 1500 gpm. Operation at these conditions is believed by the pump vendor

to cause recirculation cavitation. In addition, the RHRSW pumps are believed

to have been operated at less than 50 percent of design flow most of the time.

The licensee indicated that the cavitation damage can be avoided by operating

the pumps at higher flows; specifically, operation at 75 to 100 percent of

design flow is desirable.

Discussion:

These events illustrate that pump damage, caused by operating pumps at flows

significantly below their design flow rates, has resulted, with slow deteri- oration of pump internals occurring over a long period. During the early

phases of degradation, the pumps were still functional and remained operable.

The pumps had to be disassembled before damage to the pump internals could be

seen. Therefore, the routine pump surveillance tests, provided in the plant

inservice test programs, may not be capable of detecting early component de- gradation. In addition, while operating the pumps in their normal, specified

system operating ranges, plant personnel were not aware of a problem until

actual failure of a pump occurred. It is most likely that pump degradation

caused by low-flow operation will go undetected until total failure of the

pump occurs, preventing the associated system from performing its safety

function.

IN 89-08 January 26, 1989 No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact the technical

contact listed below or the Regional Administrator of the appropriate regional

office.

aLzi lorj

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Chuck Hsu, AEOD

(301) 492-4443 Attachment: List of Recently Issued NRC Information Notices

IN 89-08 January 26, 1989 No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact the techntcal

contact listed below or the Regional Administrator of the appropriate regional

office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Chuck Hsu, AEOD

(301) 492-4443 Attachment: List of Recently Issued NRC Information Notices

The draft of this information notice was transmitted to DOEA by AEOD in a

memorandum from Thomas M. Novak dated October 18, 1988.

The results of the review and recommendation for issuance of this draft infor- mation notice was transmitted to OGCB In a memorandum from M. Wayne Hodges

dated November 17, 1988.

• SEE PREVIOUS CONCURRENCES

• C/OGCB: DOEA:NRR*PPMB:ARM *OGCB:DOEA:NRR *AD/SAD:DEST:NRR

CHBerlinger TechEd RJKiessel ACThadani

01/11/89 12/22/88 12/06/88 12/09/88 D *ROAB:DSP:AEOD *C/ROAB:DSP:AEOD *DSP:AEOD *D/DSP:AEOD

CHsu MChiramal JERosenthal VBenoroya TMNovak

10/18/88 10/18/88 10/18/88 10/18/88 10/18/88

IN 89-XX

January xx, 1989 No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact the technical

contact listed below or the Regional Administrator of the appropriate regional

office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Chuck Hsu, AEOD

(301) 492-4443 Attachment: List of Recently Issued NRC Information Notices

The draft of this information notice was transmitted to DOEA by AEOD in a

memorandum from Thomas M. Novak dated October 18, 1988.

The results of the review and recommendation for issuance of this draft infor- mation notice was transmitted to OGCB in a memorandum from M. Wayne Hodges

dated November 17, 1988.

• SEE PREVIOUS CONCURRENCES

D/DOEA:NRR *C/OGCB:DOEA:NRR*PPMB:ARM *OGCB:DOEA:NRR *AD/SAD:DEST:NRR

CERossi CHBerlinger TechEd RJKiessel ACThadani

01/ /89 01/11/89 12/22/88 12/06/88 12/09/88

• ROAB:DSP:AEOD *ROAB:DSP:AEOD *C/ROAB:DSP:AEOD *DSP:AEOD *D/DSP:AEOD

CHsu MChiramal JERosenthal VBenoroya TMNovak

10/18/88 10/18/88 10/18/88 10/18/88 10/18/88

IN 89-XX

January xx, 1989 Discussion:

These events illustrate that pump damage, caused by operating pumps at flows

significantly below their design flow rates, has resulted with slow deteriora- tion of pump internals occurring over a long period. During the early phases

of degradation, the pumps were still functional and remained operable. The

pumps had to be disassembled before damage to the pump internals could be seen.

Therefore, the routine pump surveillance tests, provided in the plant inservice

test programs, may not be capable of detecting early component degradation. In

addition, while operating the pumps in their normal, specified operating

ranges, plant personnel were not aware of a problem until actual failure of the

pump occurred. It is most likely that pump degradation caused by low-flow

operation will go undetected until total failure of the pump occurs, preventing

the associated system from performing its safety function.

The information herein is being provided as an early notification of a poten- tially significant matter that is under further consideration by the NRC staff.

If NRC evaluation so indicates, further licensee action may be requested.

No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact the technical

contact listed below or the Regional Administrator of the appropriate regional

office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Chuck Hsu, AEOD

(301) 492-4443 Attachment: List of Recently Issued NRC Information Notices

The draft of this information notice was transmitted to DOEA by AEOD in a

memorandum from Thomas M. Novak dated October 18, 1988.

The results of the review and recommendation for issuance of this draft infor- mation notice was transmitted to OGCB in a memorandum from M. Wayne Hodges

dated November 17, 1988.

• SEE PREVIOUS CONCURR

• PPMB:ARM C/OGCB D~t4NRR D/DOEA:NRR

TechEd CHBerl hIer CERossi

12/22/88 01/1//89 01/ /89

• OGCB:DOEA:NRR *AD/SAD:DEST:NRR*C/SRXB:DEST:NRR *SRXB:DEST:NRR*SRXB:DEST:NRR

RJKiessel ACThadani MWHodges TECollins MMcCoy

12/06/88 12/09/88 12/17/88 12/17/88 12/17/88

• ROAB:DSP:AEOD *ROAB:DSP:AEOD *C/ROAB:DSP:AEOD *DSP:AEOD *D/DSP:AEOD

CHsu MChiramal JERosenthal VBenoroya TMNovak

10/18/88 10/18/88 10/18/88 10/18/88 10/18/88

IN 88-XX

December xx, 1988 during which the pumps were still functional and remained operable at early

degradation. Damage indication on the pumps' internals can only be observed by

disassembly of the pumps. The routine surveillance tests of the pumps provided

in the plant inservice test programs may not be capable of detecting early

component degradation. In addition, since the pumps operated in the specified

operating ranges, the plants were not aware of the problem until the occur- rences of pump failure. There is the potential that pump degradation due to

low flow operation could go undetected until total failure of the pump occurs.

Such failures could prevent the associated system from performing its safety

function.

The information herein is being provided as an early notification of a possibly

significant matter that is still under consideration by the NRC staff. Recipi- ents should review the information for possible applicability to their facili- ties. If NRC evaluation so indicates, further licensee action may be

requested.

No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact the technical

contact listed below or the Regional Administrator of the appropriate regional

office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Chuck Hsu, AEOD

(301) 492-4443 Attachment: List of Recently Issued NRC Information Notices

The draft of this information notice was transmitted to DOEA by AEOD in a

memorandum from Thomas M. Novak dated October 18, 1988.

The results of the review and recommendation for issuance of this draft infor- mation notice was transmitted to OGCB in a memorandum from M. Wayne Hodges

dated November 17, 1988.

• SEE PREY CONCURRENCES

PPMB:ARMitiv C/OGCB:DOEA:NRR D/DOEA:NRR

TechEd CHBerlinger CERossi

12/fe/88 12/ /88 12/ /88 OGCB:DOEA:IRI AD/SAD:DESI:PRR *C/SRXB:DEST:NRR *SRXB:DEST:NRR*SRXB:DEST:NRR

RJKiessel ACThgdani / MWHodges TECollins MMcCoy

12/6/88 12/ 1/88 12/17/88 12/17/88 12/17/88

• ROAB:DSP:AEOD *ROAB:DSP:AEOD *C/ROAB:DSP:AEOD *DSP:AEOD *D/DSP:AEOD

CHsu MChiramal JERosenthal VBenoroya TMNovak

10/18/88 10/18/88 10/18/88 10/18/88 10/18/88