Information Notice 1986-35, Fire in Compressible Material at Dresden Unit 3

Fire in Compressible Material at Dresden Unit 3

ML031250020
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:	05/15/1986
From:	Jordan E L NRC/IE
To:
References
IN-86-035, NUDOCS 8605130022
Download: ML031250020 (3)

Ls LSSINS No.: 6835IN 86-35UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF INSPECTION AND ENFORCEMENTWASHINGTON, D.C. 20555May 15, 1986IE INFORMATION NOTICE NO. 86-35: FIRE IN COMPRESSIBLE MATERIAL ATDRESDEN UNIT 3

Addressees

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

Purpose

This notice is being issued to advise recipients of the circumstances surroundinga fire which occurred at Dresden Unit 3 on January 20, 1986. It is expected thatrecipients will review the information for applicability to their facilities andconsider actions, if appropriate, to determine whether a similar fire hazardexists at their facilities. No specific action or response is required by thisnotice.

Description of Circumstances

Dresden Unit 3 is a 773 MWe BWR with a typical "light bulb" Mark I drywell,which includes a free-standing steel containment vessel. A reinforced concreteshield wall surrounds the containment vessel. To allow for thermal and pressureexpansion and contraction under design-basis conditions, an annular space ofabout 2 inches is provided between the vessel and the shield wall. After thevessel was erected and pressure tested, a composite urethane foam and fiberglasssheet was glued to the external surfaces of the vessel. This method of applicationprovides a compressible fill in the space between the vessel and the concreteto ensure that adequate freedom for motion is maintained.Dresden Unit 3 is replacing certain pipe that is part of the reactor coolantpressure boundary. In connection with this work, a pipe which penetrates theshield wall was being removed using a arc-air cutting technique. The sleeve inthe shield wall through which the pipe passes slopes downward from the outside;hot slag from the pipe cutting inadvertently ran through the sleeve and contactedthe urethane foam. The small fire which started was thought to have beenpromptly extinguished.Some time later, personnel working inside the drywell noted that the innersurface of the vessel was heated by a continuing fire such that the paint wasdiscolored in sizeable local areas. The station fire brigade reviewed plantrecords and identified the presence of the combustible foam in the annularspace. Water was applied through the penetration where the fire apparently8605130022 '

, -' ,IN 86-35May 15, 1986 started as well as through adjacent penetrations. *The temperature of the insidesurface of the steel drywell was monitored and was determined to have returnedto normal about 12h hours after the fire was first detected.Discussion:The licensee is committed to provide to the NRC an extensive evaluation ofdamage that may have been done by the fire and the repairs (if any) that may berequired, the methods of accomplishment, the consequences of a recurrence ofa fire in this or any similar space where a significant fraction of the localvolume may be occupied by combustible foam, and methods of detection andsuppression of any potential future fire. The NRC also has requested that thelicensee consider and discuss the matter of conformance to Appendix R of 10 CFR50. When the requested information is received the NRC will consider whetherfurther action is required.The reactor was shut down and defueled at the time of the fire, and resolutionof NRC concerns will be required before restart. The event is discussed ingreater detail in NRC Inspection Report No. 56-249/86006 (DRSS).*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 regional office or this office.a irectorDivisi n f Emergency Preparednessand Edineering ResponseOffice of Inspection and Enforcement

Technical Contact:

James Henderson, IE(301) 492-9654

Attachment:

List of Recently Issued IE Information Notices*NRC Inspection Report 50-249/86006 (DRSS), available for review at the NRCPublic Document Room, 1717 H St. NW, Washington, DC; the NRC Local DocumentRoom, Morris Public Library, 604 Liberty St., Morris, IL 60450; and the NRCRegion III Document Room, 799 Roosevelt Road, Glen Ellyn, IL 6013 Attachment 1IN 86-35May 15, 1986LIST OF RECENTLY ISSUED; IE INFORMATION NOTICESInformation Date ofNotice No. Subject Issue Issued to86-3486-3386-3286-3186-3086-2986-2886-27Improper Assembly, MaterialSelection, And Test Of ValvesAnd Their ActuatorsInformation For LicenseeRegarding The ChernobylNuclear Plant AccidentRequest For Collection OfLicensee RadioactivityMeasurements Attributed ToThe Chernobyl Nuclear PlantAccidentUnauthorized Transfer andLoss of Control ofIndustrial Nuclear GaugesDesign Limitations ofGaseous Effluent MonitoringSystemsEffects of Changing ValveMotor-Operator SwitchSettings5/13/865/6/865/2/865/6/864/29/864/25/86All power reactorfacilities holdingan OL or CPFuel cycle licenseesand Priority 1 materiallicenseesAll power reactorfacilities holdingan OL or CPAll power reactorfacilities holdingan OL or a CPAll power reactorfacilities holdingan OL or a CPAll power reactorfacilities holdingan OL or a CP4/28/86Access Control at NuclearFacilities4/21/86All power reactorfacilities holdingan OL or CP, researchand nonpower reactorfacilities, and fuelfabrication & pro-cessing facilities86-26Potential Problems InGenerators Manufactured ByElectrical ProductsIncorporated4/17/86All power reactorfacilities holdingan OL or CP.OL = Operating LicenseCP = Construction Permit