levels of confinement are necessary or justified. Design decisions for a specific
facility should address that facility' hazards and other factors.
Primary confinement is usually provided by piping, tanks, gloveboxes,
encapsulating material, and the like, and any off-gas system that
controls effluent from within the primary confinement. It confines
hazardous material to the vicinity of its processing.
Secondary confinement is usually provided by walls, floors, roofs, and
associated ventilation exhaust systems of the cell or enclosure
surrounding the process material or equipment. Except for glovebox
operations, the area inside this barrier provides protection for operating
Tertiary confinement is provided by the walls, floor, roof, and associated
ventilation exhaust system of the facility. Tertiary confinement provides a
final barrier against release of hazardous material to the environment.
Primary Confinement System. Primary confinement consists of barriers,
enclosures, gloveboxes, piping, vessels, tanks, and the like that contain
radioactive or other hazardous material. Its primary function is to prevent
release of radioactive or hazardous material to areas other than those in which
processing operations are normally conducted.
Primary confinement of processes that involve readily dispersible forms of
material (e.g., solutions, powder or small fragments, gases) is provided by
gloveboxes or other confining enclosures. Hoods are used when hazards are
acceptably low, as indicated by the quantity of the material involved, the specific
operation to be performed, and the hazardous nature and chemical form of
material involved. The confinement philosophy described below should be
applied to any component that serves a primary confinement function, such as
conveyor systems, material transfer stations, and ventilation/off-gas systems.