Air should flow from areas of lower contamination to areas of higher
contamination and areas of higher potential airborne contamination should be
kept less than atmospheric pressure.
Reprocessing Facilities. The following provisions are typical for a
reprocessing facility confinement system. Actual confinement system
requirements for a specific reprocessing system should be determined on a
The degree of confinement required in various locations of the facility depends
on the potential hazards associated with the process being carried out and is
generally based on the most restrictive case anticipated. Design should
consider the characteristics of the hazardous material involved, such as type,
quantities, forms (physical and chemical), dispersibility, and energy available for
In general, for the most restrictive case anticipated, the use of three
confinement systems should be considered. In reprocessing facilities where
processes require the use of corrosive or noxious materials, the process system
should be totally enclosed and provided with its own ventilation system and off-
gas cleanup system. In such cases, the process system should be treated as
the primary confinement system. Secondary confinement should consist of the
process cells and their ventilation system. Tertiary or final confinement should
be the building structure and its ventilation system. In addition to these
confinement systems, such features as change rooms and special access ways
should be used to minimize the spread of contamination within the facility.
If heat transfer systems are used that provide circulation between radioactive
and nonradioactive areas, barriers to release due to contamination of the heat
transfer fluids should be considered. Typically, confinement would be provided
through the use of intermediate heat exchangers and the use of a " losed-loop"
system. A leak monitoring system should be considered.