Confinement/Heating, Ventilating, and Air Conditioning (HVAC) Systems - Continued

DOE-STD-6003-96

ANSI 1984 and AISC 1986a provide the criteria for safety-class and other building

structures. AISC 1986b is an alternate for AISC 1986a if load and resistance factor

design procedure is used.

ASME 1992 should be used for equipment and components and ANSI 1993a for

piping.

Deformation may be allowed and inelastic energy absorption credited for ductile

structural materials, especially for lower performance categories. Inelastic absorption

capacity should not be credited if concrete or other nonductile materials are used as a

pressure boundary.

For lower performance categories and for normal operations, damage may be permit-

ted but should be limited so that hazardous materials can be controlled and confined,

occupants are protected, and safety functions are maintained.

For the higher performance categories and for off-normal conditions, structures should

be permitted to undergo limited inelastic deformations. Risk analysis may be per-

formed to determine the extent of permissible damage. Energy absorption factors may

be used to achieve appropriate conservatism in the design or evaluation process.

Stability and other postyield behavior criteria should be met.

Ventilation systems should be designed to operate in conjunction with their associated

physical barriers to limit the release of radioactive or other hazardous material to the

environment. The ventilation system capabilities should be sufficient to allow for any

intentional breaches of the confinement system that are required during maintenance

on any portion of the facility.

Leak-tightness of the confinement pressure boundary should be considered in the

design. Air locks to achieve the required leak-tightness between confine-

ment/containment zone boundary interfaces should be considered.

Appropriate filtration may be accomplished by multistage high-efficiency particulate air

(HEPA) filtration of the exhaust or by an equivalent filtering capability. The exhaust

ventilation system must be sized to ensure adequate inflow of air in the event of the

largest credible breach of confinement.

Safety-class systems and components should be designed per ASME 1993 or a com-

parable code or standard which considers the safety function(s) of the particular sys-

tem or component (ASME 1989a and ASME 1989b). Non-safety-class systems and

components should be designed per codes and standards used for industrial and

commercial grade applications.