Design Considerations - hdbk60040033

DOE-HDBK-6004-99

Safety-class systems and components should be designed per ASME AG-1 (ASME 93c) or a

comparable code or standard which considers the safety function(s) of the particular system or

component (ASME 89a, ASME 89b). Non-safety-class systems and components should be designed

per codes and standards used for industrial and commercial grade applications.

Design Considerations

Ventilation systems

1. The ventilation systems should be designed so that air flows from the cleaner areas with less

potential for contamination to the potentially more contaminated areas.

2. The ventilation system should be designed so that the system parameters which are important to

operational and nuclear safety can be monitored and if necessary tested. This includes but is not

limited to pressure, temperature, air flow, filtering efficiency, environmental releases, etc.

3. The design of the ventilation system should ensure that each of the following design parameters

can be met:

a) Required differential pressures between confinement barriers

b) Required air change rate to maintain concentrations of airborne radioactivity and other

hazardous substances at or below acceptable levels.

c) Required temperature and humidity conditions

4. The ventilation system should be capable of isolating released tritium gas (or other radiologically

hazardous gas) in the event of a breach of the confinement system. In addition the system should

be designed to limit potential releases during normal and accident conditions. The ventilation

system should be designed to control the concentrations of other radiological, toxic and explosive

substances below unacceptable levels.

5. The ventilation system should be capable of monitoring routine as well as accident releases to the

environment through all possible discharge paths.

6. The resultant leak-tightness of the confinement zone pressure boundary should be considered in

the design. Utilization of air locks to achieve the required leak-tightness between

confinement/containment zone boundary interfaces should be considered. The pressure boundary

of any confinement zone should have sufficient leak-tightness so that contamination control is

achieved without excessive in-leakage.

Structural Design Codes

General design criteria for all DOE facilities is given in the DOE Order 1020. Requirements for the

environmental, safety and health protection are given in the DOE Order 5480.4. Requirements for

natural phenomena hazards (NPH) mitigation are given in the DOE Order 5480.28 with the

accompanying DOE Standards 1020 and 1021. Although DOE 5480.28, DOE 1020 and DOE 1021

are for NPH they provide a baseline to be extended to fusion related SSCs.