Primary Confinement System

DOE-HDBK-1132-99

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

secondary confinement.

Penetrations of the secondary confinement should have positive seals to

prevent migration of contamination out of the secondary confinement

area.

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:

I-85