Information Notice 1985-24, Failures of Protective Coatings in Pipes and Heat Exchangers

Failures of Protective Coatings in Pipes and Heat Exchangers

ML031180373
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, 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, Skagit, Marble Hill, Crane
Issue date:	03/26/1985
From:	Jordan E NRC/IE
To:
References
IN-85-024, NUDOCS 8503220444
Download: ML031180373 (4)

SSINS No.:

6835 IN 85-24

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF INSPECTION AND ENFORCEMENT

WASHINGTON, D.C.

20555

March 26, 1985

IE INFORMATION NOTICE NO. 85-24:

FAILURES OF PROTECTIVE COATINGS IN PIPES

AND HEAT EXCHANGERS

Addressees

All nuclear power reactor facilities holding an operating license (OL) or

construction permit (CP).

Purpose

This information notice is provided to alert recipients of a potentially

significant problem pertaining to the selection and application of protective

coatings for safety-related use, especially painting interior surfaces of pipes

and tubing.

It is expected that recipients will review the information for

applicability to their facilities and consider actions, if appropriate, to

preclude a similar problem occurring at their facilities.

However, suggestions

contained in this information notice do not constitute NRC requirements;

therefore, no specific action or written response is required.

Description of Circumstances

1. Spray Pond Piping

While making minor repairs to the spray pond piping system in 1982, Palo

Verde Nuclear Generation Station Unit 1 personnel discovered delamination

and peeling of the interior epoxy lining in three 24-inch-diameter 900

elbows.

Examination of the remainder of the piping system showed similar

lining failures in other elbows, such as 3-inch blisters that contained

solvent, poor adhesion, soft film, and excessive film thickness.

The

spray pond is the ultimate heat sink for the Palo Verde Station.

During a

shutdown where the ultimate heat sink was needed, separation of the epoxy

lining.from the elbows could potentially cause a flow restriction in the

piping system.

The epoxy coating specified was Plasite 7122-H, a product of Wisconsin

Protective Coatings Company.

This material is formulated to be applied by

mechanical spraying equipment in layers 2-1/2 to 4 mils thick with sufficient

time allowed for each layer to cure. The use of mechanical spray equipment

provides a uniform and controlled coating film thickness.

The straight

sections of the piping system were coated in this manner.

The multilayer

mechanical deposition and curing of 12-15 mils of coating in the straight

sections of pipe took 7 days, and no discrepancies similar to those in the

elbows were found.

8503220444

IN 85-24 March 26, 1985 However, the elbows were coated in two layers using a hand-held gun.

The

lining was uneven with the coating up to 25 mils thick.

Coating took only

3 days in December of 1980; this reduction in curing time can be critical, especially in the winter when chemical curing and solvent evaporation

tends to be retarded.

In addition, the elbows, were capped after the final

coating application and there was insufficient air necessary for curing.

A hand-held gun was used to spray the coating because of the shape of the

elbow.

There are other methods of applying epoxy coatings that are more

controllable and use less solvent.

Electrostatic spray uses less epoxy

and solvent for the same coating thickness.

Electrodeposition in a water

solution provides the most uniform coating and does not use solvents. The

fluidized bed method will provide the thickest epoxy deposit. Whatever

application method is selected, epoxies are thermosetting materials and

are normally cured by oven baking or infrared heating.

Heating reduces

curing time from several days to several hours.

The elbows were repaired by removing the deficient lining, preparing the

surface by grit blasting, and recoating with Plasite 9009-IT.

The repairs

were acceptable and a final report was issued in January 1984.

2.

Diesel Generator Heat Exchangers

While operating train A of the spray pond piping system in May 1984, Palo

Verde Nuclear Generation Station Uniti2 personnel discovered an accumulation

of epoxy material.

The jacket water cooler, air after-coolers, and lube

oil coolers of all the train A and train B diesel generator heat exchangers

had extensive failure of the epoxy coating and resulted in complete

blockage of the governor oil coolers.

The failures of the epoxy coating included severe blistering, moisture

entrapment between layers of the coating, delamination, peeling, and

widespread rusting.

The epoxy coating specified was Plasite 7155-H. It

is formulated to be deposited in thin layers using mechanical spraying

equipment.

An evaluation of the deficiencies showed the presence of cutting oils on

the heat exchanger surface before the coating was applied.

It is a basic

requirement to have a dry, oil-free surface before applying coatings.

In

addition, the surface was too smooth for the epoxy coating to adhere.

Epoxy coatings are applied directly to the metal without a primer and it

is necessary to slightly roughen the metal surface.

Finally, the heat

exchangers were sealed after spraying and there was insufficient air to

complete the curing process.

Repairs were successfully made with Plasite

9009-IT and a final report was issued in September 1984.

IN 85-24 March 26, 1985 It should be noted that this information notice is not intended to imply that

Plasite materials produced by Wisconsin Protective Coatings Company are

unacceptable.

Other applications using appropriately selected materials and

application techniques have been successful.

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

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

Administrator of the appropriate regional office or this office.

EHIard

a

r

Divisio

f Emergency Preparedness

and E ineering Response

Office

P. Cortland, IE

(301) 492-4175 Attachment: List of Recently Issued IE Information Notices

Attachment 1

IN 85-24

March 26, 1985

LIST OF RECENTLY ISSUED

IE INFORMATION NOTICES

Information

Date of

Notice No.

Subject

Issue

Issued to

85-23

85-22

Inadequate Surveillance And

Postmaintenance And Post- modification System Testing

Failure Of Limitorque Motor-

Operated Valves Resulting

From Incorrect Installation

Of Pinon Gear

Main Steam Isolation Valve

Closure Logic

3/22/85

3/21/85

3/18/85

85-21

85-20

- Motor-Operated Valve Failures 3/12/85

Due To Hammering Effect

85-19

85-10

Sup. 1

84-18

Alleged Falsification Of

Certifications And Alteration

Of Markings On Piping, Valves

And Fittings

Posstensioned Containment

Tendon Anchor Head Failure

Failures Of Undervoltage

Output Circuit Boards In The

Westinghouse-Designed Solid

State Protection System

Vibration-Induced Valve

Failures

Possible Sticking Of ASCO

Solenoid Valves

Time/Current Trip Curve

Discrepancy Of ITE/Siemens-

Allis Molded Case Circuit

Breaker

3/11/85

3/8/85

3/7/85

3/4/85

3/1/85

2/27/85

All power reactor

facilities holding

an OL or CP

All power reactor

facilities holding

an OL or CP

All PWR facilities

holding an OL or CP

All power reactor

facilities holding

an OL or CP

All power reactor

facilities holding

an OL or CP

All power reactor

facilities holding

an OL or CP

All Westinghouse

PWR facilities

holding an OL or CP

All power reactor

facilities holding

an OL or CP

All power reactor

facilities holding

an OL or CP

All power reactor

facilities holding

an OL or CP

83-70

Sup. 1

85-17

85-16 OL = Operating License

CP = Construction Permit