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 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 0F. 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

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 Deficiencies In Ferro- 4/24/85 All power reactor

Rev. 1 Resonant Transformers- - facilities holding

..  :. ~ .:I; an OL or;CP

85-33 Undersized Nozzle-To-Shell 4/22/85 All power reactor

Welded Joints In Tanks And facilities holding

Heat Exciange'rs Constructed an OL or CP

Under The&Rules Of T4heASME

Boiler And Pressure Vessel

Code'

85-32 Recent-Engine Failures Of 4/22/85 All power reactor

Emergency Diesel Generators facilities holding

an OL or CP -

85-31 Buildup Of Enriched Uranium 4/19/85 All uranium fuel

In Ventilation Ducts And fabrication licensees

Associated Effluent Treatment

Systems

85-30 Microbiologically Induced 4/19/85 All power reactor

Corrosion Of Containemnt facilities holding

Service Water System an OL or CP

85-29 Use Of Unqualified Sources 4/12/85 All well logging

In Well Logging Applications source licensees

85-03 Separation Of Primary Reactor 4/9/85 All power reactor

Sup. 1 Coolant Pump Shaft And facilities holding

Impeller an OL or CP

85-28 Partial Loss Of AC Power And 4/9/85 All power reactor

Diesel Generator Degradation facilities holding

an OL or CP

85-27 Notifications To The NRC 4/3/85 All power reactor

Operations Center And facilities holding

Reporting Events In Licensee an OL or CP

Event Reports

OL = Operating License

CP = Construction Permit