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 NRC/IE
To:
References
IN-86-035, NUDOCS 8605130022
Download: ML031250020 (3)

Ls LSSINS No.: 6835 IN 86-35 UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF INSPECTION AND ENFORCEMENT

WASHINGTON, D.C. 20555 May 15, 1986 IE INFORMATION NOTICE NO. 86-35: FIRE IN COMPRESSIBLE MATERIAL AT

DRESDEN UNIT 3

Addressees

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

construction permit (CP).

Purpose

This notice is being issued to advise recipients of the circumstances surrounding

a fire which occurred at Dresden Unit 3 on January 20, 1986. It is expected that

recipients will review the information for applicability to their facilities and

consider actions, if appropriate, to determine whether a similar fire hazard

exists at their facilities. No specific action or response is required by this

notice.

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 concrete

shield wall surrounds the containment vessel. To allow for thermal and pressure

expansion and contraction under design-basis conditions, an annular space of

about 2 inches is provided between the vessel and the shield wall. After the

vessel was erected and pressure tested, a composite urethane foam and fiberglass

sheet was glued to the external surfaces of the vessel. This method of application

provides a compressible fill in the space between the vessel and the concrete

to ensure that adequate freedom for motion is maintained.

Dresden Unit 3 is replacing certain pipe that is part of the reactor coolant

pressure boundary. In connection with this work, a pipe which penetrates the

shield wall was being removed using a arc-air cutting technique. The sleeve in

the shield wall through which the pipe passes slopes downward from the outside;

hot slag from the pipe cutting inadvertently ran through the sleeve and contacted

the urethane foam. The small fire which started was thought to have been

promptly extinguished.

Some time later, personnel working inside the drywell noted that the inner

surface of the vessel was heated by a continuing fire such that the paint was

discolored in sizeable local areas. The station fire brigade reviewed plant

records and identified the presence of the combustible foam in the annular

space. Water was applied through the penetration where the fire apparently

8605130022'

, -' ,IN 86-35 May 15, 1986 started as well as through adjacent penetrations. *The temperature of the inside

surface of the steel drywell was monitored and was determined to have returned

to normal about 12h hours after the fire was first detected.

Discussion:

The licensee is committed to provide to the NRC an extensive evaluation of

damage that may have been done by the fire and the repairs (if any) that may be

required, the methods of accomplishment, the consequences of a recurrence of

a fire in this or any similar space where a significant fraction of the local

volume may be occupied by combustible foam, and methods of detection and

suppression of any potential future fire. The NRC also has requested that the

licensee consider and discuss the matter of conformance to Appendix R of 10 CFR

50. When the requested information is received the NRC will consider whether

further action is required.

The reactor was shut down and defueled at the time of the fire, and resolution

of NRC concerns will be required before restart. The event is discussed in

greater 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 Regional

Administrator of the appropriate regional office or this office.

a irector

Divisi n f Emergency Preparedness

and Edineering Response

Office of Inspection and Enforcement

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 NRC

Public Document Room, 1717 H St. NW, Washington, DC; the NRC Local Document

Room, Morris Public Library, 604 Liberty St., Morris, IL 60450; and the NRC

Region III Document Room, 799 Roosevelt Road, Glen Ellyn, IL 60137.

Attachment 1 IN 86-35 May 15, 1986 LIST OF RECENTLY ISSUED

IE INFORMATION NOTICES

Information Date of

Notice No. Subject Issue Issued to

86-34 Improper Assembly, Material 5/13/86 All power reactor

Selection, And Test Of Valves facilities holding

And Their Actuators an OL or CP

86-33 Information For Licensee 5/6/86 Fuel cycle licensees

Regarding The Chernobyl and Priority 1 material

Nuclear Plant Accident licensees

86-32 Request For Collection Of 5/2/86 All power reactor

Licensee Radioactivity facilities holding

Measurements Attributed To an OL or CP

The Chernobyl Nuclear Plant

Accident

86-31 Unauthorized Transfer and 5/6/86 All power reactor

Loss of Control of facilities holding

Industrial Nuclear Gauges an OL or a CP

86-30 Design Limitations of 4/29/86 All power reactor

Gaseous Effluent Monitoring facilities holding

Systems an OL or a CP

86-29 Effects of Changing Valve 4/25/86 All power reactor

Motor-Operator Switch facilities holding

Settings an OL or a CP

86-28 4/28/86

86-27 Access Control at Nuclear 4/21/86 All power reactor

Facilities facilities holding

an OL or CP, research

and nonpower reactor

facilities, and fuel

fabrication & pro- cessing facilities

86-26 Potential Problems In 4/17/86 All power reactor

Generators Manufactured By facilities holding

Electrical Products an OL or CP

Incorporated

. OL = Operating License

CP = Construction Permit