Information Notice 1989-17, Contamination and Degradation of Safety-Related Battery Cells

Contamination and Degradation of Safety-Related Battery Cells

ML031180527
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, 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:	02/22/1989
From:	Rossi C Office of Nuclear Reactor Regulation
To:
References
IN-89-017, NUDOCS 8902150140
Download: ML031180527 (6)

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 February 22, 1989 NRC INFORMATION NOTICE NO. 89-17: CONTAMINATION AND DEGRADATION OF

SAFETY-RELATED BATTERY CELLS

Addressees

All holders of operating licenses or construction permits for nuclear power

reactors.

Purpose

This information notice is being provided to alert addressees to reports of

contamination and degradation of safety-related battery cells. It is expected

that recipients will review the information for applicability to their facili- ties and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in this information notice do not constitute NRC require- ments; therefore, no specific action or written response is required.

Description of Circumstances

Several licensees for nuclear power plants have identified contamination and

degradation of safety-related battery cells that resulted In decreased station

battery voltages. This information notice details such discoveries at the Peach

Bottom Atomic Power Station, Unit 2; St. Lucie Plant, Units 1 and 2; and the

Duane Arnold Energy Center.

Copper Contamination

On July 29, 1988, the Philadelphia Electric Company (PECo) reported to the NRC

pursuant to 10 CFR Part 21 that it had discovered copper contamination on the

negative plates of the station batteries at its Peach Bottom Atomic Power

Station, Unit 2. The station batteries at the Peach Bottom station are 125-volt

direct current (dc) Exide Corporation GN-23 batteries. Similarly in 1987, Florida Power & Light Co. (FP&L) personnel noted that approximately 97 out of

240 safety-related battery cells at the St. Lucie Plant, Units 1 and 2, showed

signs of discoloration and copper contamination. The batteries at the St. Lucie

Plant are 125-volt C&D Power Systems, Inc., type LC-33.

The copper contamination at the Peach Bottom and St. Lucie plants was caused by

the battery electrolyte attacking the copper inserts in the cells' positive

terminal posts. The copper inserts improve the current-carrying capability of

the posts and are normally isolated from attack by the electrolyte by a lead

coating. According to Exide and C&D, the copper does not remain isolated from

7902150140

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-~ _

IN 89-17 February 22, 1989 electrolyte attack throughout the design life of the cell if improper alignment

or casting occurred at the time of manufacture. For example, gases caught in

the lead coating during the casting and freezing involved in the manufacturing

process may later develop into perforations that become a path between the

battery electrolyte and the copper inserts.

The battery electrolyte attacks all copper and cupric alloys, causing copper to

deposit on the negative plates of the affected cell. The first typical indica- tion of copper contamination is the discoloration, a pinkish-red color, of the

negative plates and straps, and as the contamination progresses, the discolora- tion works its way down the negative plates. This condition can quickly lead to

loss of battery capacity and serious deterioration.

At Peach Bottom, Unit 2, a total of 19 cells in four station batteries exhibited

copper contamination. PECo revised the Peach Bottom station battery surveil- lance tests to include checks for signs of discoloration on the negative plates

during testing of cell voltages and specific gravity.

FP&L, based on C&D recommendations, augmented its Technical Specification

surveillances for safety-related battery cells until replacement of all cells

showing signs of contamination was completed. The additional surveillances

included (1) weekly visual inspections of each cell to monitor the extent of

copper buildup on the negative plates; (2) weekly voltage monitoring and trending

of all cells exhibiting signs of copper contamination, including recording the

temperature, specific gravity, and electrolyte level of each of these monitored

cells; and (3) weekly monitoring and trending of battery terminal voltages.

Degradation

In late 1986, personnel at the Duane Arnold Energy Center (DAEC) observed

crumbling or eating away of the positive plates on 12 out of 120 cells in

the station battery. The degradation is believed to have been caused by a

galvanic reaction from impurities in the plate weld materials. The battery

cells are 250-volt dc GNB Batteries, Inc. (formerly Gould, Inc.), Model FPS-17.

The degradation consisted of crumbling or eating away of positive plates approx- imately 1 to 2 inches below the welded connection of the positive plate to the

cell's internal positive bus bar. According to DAEC personnel, the crumbling

appears to have originated at the edge of the plate and to have worked inward, thus reducing the plate-to-bus bar junction area. The GNB representative noted

that the severely degraded areas took on a brown appearance as opposed to the

normal flat black color. Sparkling was also noted when a light was shone on the

degraded areas, indicating sulfation. After the initial inspection, GNB deter- mined that 14 cells were significantly degraded.

The degradation at DAEC progressed rapidly after its discovery. In one in- stance, a cell noted to be 50 percent to 75 percent degraded was reexamined

less than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> later and was found disconnected from the bus bar. Although

the exact root cause of the degradation was not determined, it is believed that

impurities introduced into the plates during the welding process, combined with

aging, resulted in the galvanic reaction. GNB noted that high temperatures may

I &

IN 89-17 February 22, 1989 accelerate the degradation. DAEC indicated that the degraded cells

in the upper tier of the two tier-rack, approximately 2 feet higher were located

cells in the lower rack. In addition, the ventilation in the batterythan the

may not have been sufficient and may have contributed to the degradation cell room

rate.

DAEC augmented its battery cell inspections after the initial degradation

identified to include daily visual inspections of degraded cells was

and biweekly

inspections of non-degraded cells. Periodic cleaning of all the

nals also was incorporated into the preventive maintenance program. battery termi- Discussion:

Station batteries provide a reliable source of dc current for many

related functions. Degradation and contamination, as described safety- above, can

render the station batteries incapable of delivering sufficient capacity

perform these functions. In most instances, normal battery surveillance to

grams including total battery voltage, individual cell voltage, electrolyte pro- specific gravity, level and temperature, and visual inspections, indicators of the overall physical condition of a battery and are are the best

identifying cell degradation or contamination. In cases in which capable of

degradation or

contamination occur, the battery vendor plays an important role

appropriate recommendations and in determining the root cause of in providing the

a problem.

Once degradation or contamination is identified, an augmented

program may be necessary to monitor the battery condition and surveillance

replacement of cells may be needed. to estimate when

Adaitional guidance on battery surveillance requirements is provided

Institute of Electrical and Electronics Engineers (IEEE) Standards in the

1980, "IEEE Recommended Practice for Maintenance, Testing and 540-1975 and

Replacement of

Large Lead Storage Batteries for Generating Stations and Substations."

No specific actions or written response is required by this information

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

technical

contact listed below or the Regional Administrator of the appropriate

office. regional

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Jaime Guillen, NRR

(301) 492-1170

Attachment: List of Recently Issued NRC Information Notices

IN 89-17 February 22, 1989 accelerate the degradation. DAEC indicated that the degraded cells were located

in the upper tier of the two tier-rack, approximately 2 feet higher than the

cells in the lower rack. In addition, the ventilation in the battery cell room

may not have been sufficient and may have contributed to the degradation rate.

DAEC augmented its battery cell inspections after the initial degradation was

identified to Include daily visual inspections of degraded cells and biweekly

inspections of non-degraded cells. Periodic cleaning of all the battery termi- nals also was incorporated into the preventive maintenance program.

Discussion:

Station batteries provide a reliable source of dc current for many safety- related functions. Degradation and contamination, as described above, can

render the station batteries incapable of delivering sufficient capacity to

perform these functions. In most instances, normal battery surveillance pro- grams including total battery voltage, individual cell voltage, electrolyte

specific gravity, level and temperature, and visual Inspections, are the best

indicators of the overall physical condition of a battery and are capable of

identifying cell degradation or contamination. In cases in which degradation or

contamination occur, the battery vendor plays an important role in providing the

appropriate recommendations and in determining the root cause of a problem.

Once degradation or contamination is identified, an augmented surveillance

program may be necessary to monitor the battery condition and to estimate when

replacement of cells may be needed.

Additional guidance on battery surveillance requirements is provided in the

Institute of Electrical and Electronics Engineers (IEEE) Standards 540-1975 and

1980, "IEEE Recommended Practice for Maintenance, Testing and Replacement of

Large Lead Storage Batteries for Generating Stations and Substations."

No specific actions 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

Jaime Guillen, NRR

(301) 492-1170

Attachment: List of Recently Issued NRC Information Notices

Draft information notice on this subject was transmitted by Jacque Durr, Region I to C. H. Berlinger by mejorandum dated September 20, 1989.

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IN 89-XX

February xx, 1989 accelerate the degradation. DAEC indicated that the degraded cells were located

in the upper tier of the two tier-rack, approximately 2 feet higher than the

cells In the lower rack. In addition, the ventilation in the battery cell room

may not have been sufficient and may have contributed to the degradation rate.

DAEC augmented its battery cell inspections after the initial degradation was

identified to include daily visual inspections of degraded cells and biweekly

inspections of non-degraded cells. Periodic cleaning of all the battery termi- nals also was incorporated into the preventive maintenance program.

Discussion:

Station batteries provide a reliable source of dc current for many safety- related functions. Degradation and contamination, as described above, can

render the station batteries incapable of delivering sufficient capacity to

perform these functions. In most instances, normal battery surveillance pro- grams including total battery voltage, individual cell voltage, electrolyte

specific gravity, level and temperature, and visual inspections, are the best

indicators of the overall physical condition of a battery and are capable of

identifying cell degradation or contamination. In cases in which degradation or

contamination occur, the battery vendor plays an important role in providing the

appropriate recommendations and in determining the root cause of a problem.

Once degradation or contamination is identified, an augmented surveillance

program may be necessary to monitor the battery condition and to estimate when

replacement of cells may be needed.

Additional guidance on battery surveillance requirements is provided in the

Institute of Electrical and Electronics Engineers (IEEE) Standards 540-1975 and

1980, "IEEE Recommended Practice for Maintenance, Testing and Replacement of

Large Lead Storage Batteries for Generating Stations and Substations."

No specific actions 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

Jaime Guillen, NRR

(301) 492-1170

Attachment: List of Recently Issued NRC Information Notices

Draft information notice on this subject was transmitted by Jacque Durr, Region I to C. H. Berlinger by.memorandum dated September 20, 1989.

• SEE PREVIOUS CONCURRENCES D/DOEA:NRR *C/OGCB:DOEA:NRR *PPIMB: ARM

CERossi CHBerlinger Tec hEd

02/ /89 02/09/89 01/

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JGuillen JKnight FRosa AThadani LCSI ao

01/31/89 02/06/89 02/06/89 02/06/89 02/ (p89

IN 89-XX

February xx, 1989 accelerate the degradation. DAEC indicated that the degraded cells were located

in the upper tier of the two tier-rack, approximately 2 feet higher than the

cells in the lower rack. In addition, the ventilation in the battery cell room

may not have been sufficient and may have contributed to the degradation rate.

DAEC augmented its battery cell inspections after the initial degradation was

identified to include daily visual inspections of degraded cells and biweekly

inspections of non-degraded cells. Periodic cleaning of all the battery termi- nals also was incorporated into the preventive maintenance program.

Discussion:

Station batteries provide a reliable source of dc current for many safety- related functions. Degradation and contamination, as described above, can

render the station batteries incapable of delivering sufficient capacity to

perform these functions. In most instances, normal battery surveillance pro- grams including total battery voltage, individual cell voltage, electrolyte

specific gravity, level and temperature, and visual inspections, are the best

indicators of the overall physical condition of a battery and are capable of

identifying cell degradation or contamination. However, once degradation or

contamination is identified, an augmented surveillance program is necessary to

monitor the battery's condition and to estimate the time before replacement of

cells Is required. In such cases, the battery vendor plays an important role in

providing the appropriate recommendations and the possible root cause of a

problem.

Additional guidance on battery surveillance requirements is provided in the

Institute of Electrical and Electronics Engineers (IEEE) Standards 540-1975 and

1980, "IEEE Recommended Practice for Maintenance, Testing and Replacement of

Large Lead Storage Batteries for Generating Stations and Substations."

No specific actions 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

Jaime Guillen, NRR

(301) 492-1170

Attachment: List of Recently Issued NRC Information Notices

Draft information notice on this subject was transmitted by Jacque Durr, Region I to C. H. Berlinger by memorandum dated September 20, 1989.,

• SEE PREVIOUS CONCURRENCES D/DOEA:NRR C/OG20189 14-NRR

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