Fire Mitigation Design and Practices

DOE-HDBK-3010-94

Appendix B; Production Support Lab

3.1.5.3 F ire M itigation D esign an d P ractices

Whenever possible, construction materials are noncombustible or fire resistant. The exterior

walls and roof of the building have a minimum 2-hour fire rating while the concrete interior

walls and gypsum board over steel stud walls have minimum 2- and 1-hour fire ratings

respectively. Major structural components of the gloveboxes and process material are made

of noncombustible material.

Combustible liquids are not allowed in gloveboxes as part of the combustible loading control

program in effect, except for one 50-ml bottle of a hexone-based solvent used for sample

extractions. Potentially combustible wipes are limited by this program as well to

approximately six in line at any one time. In normal operation, non-installed combustibles in

the operating areas consist of desks, chairs, papers and books, electrical insulation, and

flammable liquid storage cabinets. The latter normally contain several liter bottles of a

hexone-based extraction solvent and/or several bottles of flammable chemicals such as ether,

as well as miscellaneous cleaning chemicals.

A reasonable amount of clutter, largely in the form of empty sample vials (glass or impact-

resistant plastic), tools, and glassware, can be found in analytical gloveboxes. However, the

major sources of combustible material in lab gloveboxes are electrical wiring, glovebox

gloves, sample label paper, and possibly sample vials if temperatures become hot enough.

Wiring is installed in accordance with codes and housed in conduits or sealed raceways.

Wiring penetrates gloveboxes through pave connectors to prevent an insulation fire from

progressing into gloveboxes. The glovebox gloves are made of materials such as Hypalon

and will melt and burn at elevated temperatures. However, the number of gloves is limited,

and storage of used gloves in a line after removal is forbidden by procedure.

3.1.5.4 F ire D etection an d A larm S ystem

The lab has three types of fire detectors available: ionization, photoelectric, and thermal. All

three are used in individual rooms, while only thermal detectors are used in gloveboxes and

ventilation plenums. Exceeding the setpoint on any detector will initiate an alarm in the

operating area, the facility control room, and the site fire department. Failure of a detector

and interruption of signal flowpath by such means as a wire break will initiate an alarm as

well.

3.1.5.5 F ire S u p p ression S ystem

All analytical areas of the lab are equipped with automatic wet-pipe sprinklers in the

overhead, which actuate at temperatures slightly higher (approximately 155 F) than the fire

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