Areas should be compartmented to isolate the high-risk areas, thereby minimizing
productivity and financial loss if an accident occurs.
A modular construction concept should be used where feasible to facilitate
recovery from operational accidents and DBAs and to provide versatility.
All movement of personnel, material, and equipment between the process area and
the uncontrolled area should be through a controlled area or an air lock. Doors that
provide direct access to the process area from the uncontrolled area (including the
outside of the building) should not be permitted. If such doors are required by
existing design and operating requirements for emergency exits, special
administrative controls should be implemented to ensure adequate ventilation and
radioactivity control. All such doors should have airtight seals. Doors without air
locks should have alarms that sound when the doors are opened to signal a breach
in the contamination control system.
Personnel exits should be provided in accordance with the NFPA Life Safety Code
(NFPA, 1985). Personnel working in areas where an accidental breach of primary
confinement will expose them to radioactive material should be located within 75 ft
of an exit that leads into the next confinement barrier. Such a barrier should be a
partition separating two different air-control zones, the area of refuge being on the
upstream side of the barrier. The airflow through the barrier should be in the
opposite direction of the exit travel.
Normal administrative traffic should be restricted to the uncontrolled and
controlled areas and should not require passage through the process area. Process
traffic should be restricted to process and controlled areas and should not require
passage through uncontrolled areas. Consideration should be given for provision of
a ready room near or within the process area where maintenance, operating, and
monitoring personnel may be readily available. The room should be in a low
background area. Storage should be provided for instruments and tools needed for
Process areas should be located to permit ease of egress and material movement to
ensure rapid evacuation in case of an accident and minimum potential for
contamination spread during movement of material.
Indicators, auxiliary units, and equipment control components that do not have to
be adjacent to operating equipment should be installed outside of radiation or
contaminated areas. Units and components without internal contamination that are
located in radiation areas should be designed so that they can be removed as
quickly as possible.
Equipment that requires frequent servicing or maintenance should be of modular
construction, standardized to the extent possible, and located outside the process
area if possible.
In radiation areas, work spaces around equipment that require maintenance (e.g.,
pumps, valves) should be shielded to conform to the design-basis radiation levels.