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
Revision:	0
From:	Jordan E L NRC/IE
To:
References
IN-85-034, NUDOCS 8504250452
Download: ML031180331 (3)

SSINS No.: 6835IN 85-34UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF INSPECTION AND ENFORCEMENTWASHINGTON, D.C. 20555April 30,, 1985IE INFORMATION NOTICE NO. 85-34: HEAT TRACING CONTRIBUTES TO CORROSION FAILUREOF STAINLESS STEEL PIPING

Addressees

All nuclear power reactor facilities holding an operating license (OL) or aconstruction permit (CP). -

Purpose

This information notice is provided to alert recipients of a potentiallysignificant problem pertaining to the use of heat tracing, especially withtubes containing traces of chemical contamination. It is expected that recipi-ents will review the information in this notice.for applicability to theirfacilities and consider actions, if appropriate, to preclude a similar problemoccurring at their facilities. However, suggestions contained in this informa-tion notice do not constitute NRC requirements; therefore, no specific actionor written response is required.

Description of Circumstances

On December 7, 1984, Pilgrim Nuclear Power Station reported seven through-wallcracks in 50 feet of type 304 stainless steel piping that was installed in ahorizontal position. The 1 inch piping is part of the postaccident samplingsystem (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 approximately2700F. 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. Duringinstallation it was filled with clean water several times for hydrostatictesting and flushing of the system. The water was removed by blowing airthrough 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 pipessagged, and applying heat to these areas resulted in chloride-induced stresscorrosion cracking in those regions.8504250452 IN 85-34April 30, 1985 The noteworthy aspect of this eventis that the trace chemicals in the waterwill 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 thegas samples. Repeated evaporation will lead to a buildup of chemicals and mayeventually 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 RegionalAdministrator of the appropriate NRC regional office or this office.I Jordan, DirectorDivis of Emergency Preparednessan Engineering ResponseOffice of Inspection and Enforcement

Technical Contact:

P. Cortland, IE(301) 492-4175

Attachment:

List of Recently Issued IE Information Notices Attachment 1IN 85-34April 30, 1985.LIST OF RECENTLY ISSUEDIE INFORMATION NOTICESInformation -'Date ofNotice No.. Subject Issue Issued to84-84Rev. 1Deficiencies In Ferro-Resonant Transformers- -..~ :. .:I;85-3385-32Undersized Nozzle-To-ShellWelded Joints In Tanks AndHeat Exciange'rs ConstructedUnder The&Rules Of T4heASMEBoiler And Pressure VesselCode'Recent-Engine Failures OfEmergency Diesel GeneratorsBuildup Of Enriched UraniumIn Ventilation Ducts AndAssociated Effluent TreatmentSystemsMicrobiologically InducedCorrosion Of ContainemntService Water SystemUse Of Unqualified SourcesIn Well Logging Applications4/24/854/22/854/22/854/19/854/19/854/12/8585-31All power reactorfacilities holdingan OL or;CPAll power reactorfacilities holdingan OL or CPAll power reactorfacilities holdingan OL or CP -All uranium fuelfabrication licenseesAll power reactorfacilities holdingan OL or CPAll well loggingsource licenseesAll power reactorfacilities holdingan OL or CPAll power reactorfacilities holdingan OL or CPAll power reactorfacilities holdingan OL or CP85-3085-2985-03Sup. 185-2885-27Separation Of Primary Reactor 4/9/85Coolant Pump Shaft AndImpellerPartial Loss Of AC Power AndDiesel Generator DegradationNotifications To The NRCOperations Center AndReporting Events In LicenseeEvent Reports4/9/854/3/85OL = Operating LicenseCP = Construction Permit