Enclosures (as primary confinement)

DOE-HDBK-1132-99

rapidly remove heat produced by fire to prevent or minimize

pressurization of a process confinement and

rapidly extinguish a fire to minimize the loading of ventilation

system filters with combustion products.

(See DOE-STD-1066, Fire Protection Criteria, and DOE-STD-3020,

Specifications for HEPA Filters Used by DOE Contractors.)

The introduction of the extinguishing agent in a way that does not result

in overpressurization of the confinement barriers.

Provisions to collect liquid agents when a wet suppression agent is used.

Enclosures (as primary confinement). Enclosures are physical barriers

(e.g., cells, cubicles, gloveboxes, fume hoods, conveyor tunnels) that, together

with their ventilation and operating systems, prevent the release of radioactive

or other hazardous material to the work space or the environment. Accordingly,

their structural and confinement integrity is a design consideration. [See the

American Conference of Governmental Industrial Hygienists (ACGIH) Industrial

Ventilation: A Manual of Recommended Practice (ACGIH 2090); American

Society of Mechanical Engineers (ASME) Code on Nuclear Air and Gas

Treatment (ASME AG-1); and Energy Research and Development

Administration (ERDA) Nuclear Air Cleaning Handbook (ERDA-76-21).]

Enclosures should be designed to prevent exposure of personnel to airborne

contamination and to implement ALARA concepts to minimize operator

exposures. The enclosure system, including its internal and external support

structures, should therefore be designed to withstand the effects of normal

operating conditions, anticipated events, and accidents. Criticality

considerations, when needed, should include water or other liquid sources,

potential liquid level in the enclosure (during operations or fire fighting), drains to

limit liquid level in the enclosure, and liquid collection in depressions, walls, and

other areas.

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