Tertiary confinements are not needed in most cases for radioactive solid
waste during the treatment or interim storage phase of the radioactive
solid waste management process. Tertiary confinement for radioactive
solid waste is typically considered to be the geologic structure of the site.
In addition to these principal confinement systems, features such as
change rooms and special access ways should be used to minimize the
spread of radioactive contamination within the facility.
Primary Confinement System. The primary confinement system consists of
process system equipment and its associated ventilation and off-gas system,
storage containers, or other waste and site-specific engineered barriers.
Secondary Confinement System . The secondary confinement system
consists of the process cell barriers and the ventilation systems associated with
the cells or building, or a storage building or structure. In some cases, a drum,
cask, or other waste and site-specific engineered barrier should provide
Penetrations of the secondary confinement should have positive seals to
prevent migration of contamination out of the secondary confinement
Process cells should be supplied with ventilation air from the building
ventilation system, and should be provided with exhaust ventilation to
control ventilation flow in the event of a credible breach in the secondary
confinement barrier. Pressure in the compartments should be negative
with respect to the building ventilation system. Special features (e.g., air
locks or enclosed vestibules) should be considered for access through
secondary and tertiary confinement barriers.
Tertiary Confinement System . The natural geologic setting comprises the
tertiary confinement system. The tertiary confinement system should meet the
following performance objectives: