Information Notice 1985-34, Heat Tracing Contributes to Corrosion Failure of Stainless Steel Piping

Heat Tracing Contributes to Corrosion Failure of Stainless Steel Piping

ML031180331
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, Skagit, Marble Hill
Issue date:	04/30/1985
From:	Jordan E L NRC/IE
To:
References
IN-85-034, NUDOCS 8504250452
Download: ML031180331 (3)

SSINS No.: 6835 IN 85-34 UNITED STATES NUCLEAR REGULATORY

COMMISSION

OFFICE OF INSPECTION

AND ENFORCEMENT

WASHINGTON, D.C. 20555 April 30,, 1985 IE INFORMATION

NOTICE NO. 85-34: HEAT TRACING CONTRIBUTES

TO CORROSION

FAILURE OF STAINLESS

STEEL PIPING

Addressees

All nuclear power reactor facilities

holding an operating

license (OL) or a construction

permit (CP). -

Purpose

This information

notice is provided to alert recipients

of a potentially

significant

problem pertaining

to the use of heat tracing, especially

with tubes containing

traces of chemical contamination.

It is expected that recipi-ents will review the information

in this notice.for

applicability

to their facilities

and consider actions, if appropriate, to preclude a similar problem occurring

at their facilities.

However, suggestions

contained

in this informa-tion notice do not constitute

NRC requirements;

therefore, no specific action or written response is required.Description

of Circumstances:

On December 7, 1984, Pilgrim Nuclear Power Station reported seven through-wall

cracks in 50 feet of type 304 stainless

steel piping that was installed

in a horizontal

position.

The 1 inch piping is part of the postaccident

sampling system (PASS) and the containment

atmospheric

continuous

monitoring

system.The cracks were discovered

during final testing, before initial service.The piping was installed

in August 1984 with heat tracing set for approximately

270 0 F. During the installation

and calibration

of the heat tracing equipment, temperatures

were periodically

higher in various portions of the piping.Although the lines were intended to have a slope for draining purposes, inter-face requirements

led to a horizontal

line.The piping carries gas samples and heat tracing is used to keep it dry. During installation

it was filled with clean water several times for hydrostatic

testing and flushing of the system. The water was removed by blowing air through the pipe and using the heat tracing for final drying. During evapora-tion, the chlorides

present in the water concentrated

where the pipe sagged.The combination

of concentrating

the chlorides, having regions where the pipes sagged, and applying heat to these areas resulted in chloride-induced

stress corrosion

cracking in those regions.8504250452 IN 85-34 April 30, 1985 The noteworthy

aspect of this eventis that the trace chemicals

in the water will concentrate

as the water is being evaporated

by the use of heat tracing.The water may be introduced

duri.ng hydrostatic

testing or as moisture in the gas samples. Repeated evaporation

will lead to a buildup of chemicals

and may eventually

cause corrosion

of the piping that is kept hot by the heat tracing.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

NRC regional office or this office.I Jordan, Director Divis of Emergency

Preparedness

an Engineering

Response Office of Inspection

and Enforcement

Technical

Contact: P. Cortland, IE (301) 492-4175 Attachment:

List of Recently Issued IE Information

Notices

Attachment

1 IN 85-34 April 30, 1985.LIST OF RECENTLY ISSUED IE INFORMATION

NOTICES Information

-'Date of Notice No.. Subject Issue Issued to 84-84 Rev. 1 Deficiencies

In Ferro-Resonant Transformers-

-..~ :. .:I;85-33 85-32 Undersized

Nozzle-To-Shell

Welded Joints In Tanks And Heat Exciange'rs

Constructed

Under The&Rules

Of T4heASME Boiler And Pressure Vessel Code'Recent-Engine

Failures Of Emergency

Diesel Generators

Buildup Of Enriched Uranium In Ventilation

Ducts And Associated

Effluent Treatment Systems Microbiologically

Induced Corrosion

Of Containemnt

Service Water System Use Of Unqualified

Sources In Well Logging Applications

4/24/85 4/22/85 4/22/85 4/19/85 4/19/85 4/12/85 85-31 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 uranium fuel fabrication

licensees All power reactor facilities

holding an OL or CP All well logging source licensees 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 85-30 85-29 85-03 Sup. 1 85-28 85-27 Separation

Of Primary Reactor 4/9/85 Coolant Pump Shaft And Impeller Partial Loss Of AC Power And Diesel Generator

Degradation

Notifications

To The NRC Operations

Center And Reporting

Events In Licensee Event Reports 4/9/85 4/3/85 OL = Operating

License CP = Construction

Permit