Confinement Ventilation Systems cont'd

DOE-HDBK-1132-99

sampling probe as possible. Guidance for air cleaning device test port

locations is provided by ASME N510, Testing of Nuclear Air-Treatment

Systems.

The number of air filtration stages required for any area of a facility

should be determined based on the quantity and type of radioactive

materials to be confined.

Air filtration units should be installed as close as practical to the source

of contaminants to minimize the contamination of ventilation system

ductwork.

Ducts should be sized for the transport velocities needed to convey

particulate contaminants to filter media while minimizing the settling of

those contaminants in the ducts.

Ducts should be welded (transverse or longitudinal). Connections to

equipment should be made using companion angle flanges.

Air filtration units should be located and provided with appropriate

radiation shielding to maintain occupational doses ALARA during

operations and maintenance.

Air filtration units should be designed to facilitate recovery of fissile

material and other materials capable of sustaining a chain reaction .

The cleanup system should have installed test and measuring devices

(see ASME N510) and should facilitate monitoring operations,

maintenance, and periodic inspection and testing during equipment

operation or shutdown, as appropriate.

Misters to cool inlet air and demisters to prevent soaking HEPA filters

should be installed. Manual control of misters from the facility control

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