On January 25, 1995, a fire occurred in a glovebox at the Los Alamos Plutonium Processing Facility where a portion of a metallographic sample fell into a nearby terry towel, causing it to catch fire. The employee quickly extinguished the fire, precluding the actuation of heat detectors in the glovebox. There was no release of radioactivity from the glovebox and no indication of airborne radioactivity. The health and safety of facility personnel were unaffected by this event. (ORPS Report ALO-LA-LANL-TA55-1995-0002)

The employee was preparing a plutonium-uranium metallographic sample for mounting into a lucite holder. As the employee was preparing the sample, a small amount of the oxidized metal fell onto a nearby terry towel. The employee observed sparks and a small flame. The employee picked up the terry towel in his gloved hand and crumpled it. He then placed the towel into an adjacent transfer chamber, and filled the chamber with nitrogen, extinguishing the fire. After the chamber was filled with nitrogen, the employee drew a vacuum on the chamber and notified facility supervision. Although there was no procedure for extinguishing a fire in this manner, facility management indicated that the employee's actions were consistent with the employee's training on glovebox fires, and that the employee acted properly.

Facility personnel moved the terry towel into a metal container glovebox which had an inert atmosphere. Health Physics personnel surveyed the front of both gloveboxes and the immediate area. No detectable contamination was found. Additionally, the fixed head air sample filters in the vicinity of the gloveboxes were surveyed and no detectable airborne radioactivity was found.

Facility management initiated the following corrective actions in response to the event:

- refurbish the glovebox to include an inert atmosphere,

- temporarily relocate the plutonium-uranium metallographic sample preparation process to a different glovebox that contains an inert atmosphere,

- evaluate the placement of combustibles (such as cloth and rags) in the gloveboxes relative to thermal sources, and

- assess the facility's overall glovebox operation to determine corrective actions to prevent future glovebox fires.

Glovebox fires can breach barriers intended to prevent the spread of contamination as well as constitute an industrial safety hazard. During 1994, the OE Weekly Summary twice reported on glovebox fire events. The first was at Savannah River, where a polyester cleaning rag lying on a 120-Vac multiplug outlet strip caught fire (OEWS 94-16, ORPS Report SR--WSRC-HBLINE-1994-0008). The second event occurred at Los Alamos National Laboratory, where a cotton rag containing Pu-238 caught fire (OEWS 94-48, ORPS Report ALO-LA-LANL-TA55-1994-0033). A review of the Occurrence Reporting and Processing System also identified numerous instances of failed glovebox fire protection systems, missed glovebox fire protection system surveillances and inappropriate glovebox fire protection related activities.

The Department of Energy has prepared a draft standard entitled, Glovebox Fire Protection. This standard, which is currently being reviewed will address all aspects of fire protection as it relates to gloveboxes including hazards analysis, construction, ventilation, and procedures governing fire protection activities in gloveboxes. To obtain additional information on the standard, please contact Dennis Kubicki (EH-512) at 301-903-4794, fax 301-903-2239.