measures to provide negative operating pressure in the secondary
confinement with respect to the tertiary confinement, especially where
variable flow primary confinement exhaust systems (fume hoods) are
Tertiary Confinement System . The tertiary confinement system typically is the
exterior laboratory building and its associated ventilation system. It is an area
that is not contaminated and houses offices and other clean laboratory facilities.
The following design features should be incorporated into tertiary confinement
systems for laboratory facilities:
the use of a ventilation system separate from the primary confinement
ventilation system with appropriate air-cleaning capabilities (e.g., HEPA
filtration, radioiodine absorbers, scrubbers) and
measures to maintain operating pressure in the tertiary confinement
negative with respect to the atmosphere.
The secondary and tertiary confinement ventilation systems may be shared if
safety analysis indicates that this type of design is acceptable.
EFFLUENT CONTROL AND RADIATION PROTECTION
Introduction and Scope . This section addresses aspects of facility design
specifically intended to provide for effluent control and radiation worker
control, and effluent monitoring. This treatment is not exhaustive; many lessons
learned in design have been translated into regulations, Orders, and guidance
documents, especially 10 CFR 835, Occupational Radiation Protection; the
DOE RADIATION CONTROL MANUAL; and DOE O 420.1 and its guidance
Design of nuclear facilities should minimize personnel exposures to external and