General Safety Design Criterion

DOE-HDBK-6004-99

General Safety Design Criterion

The cooling systems should remove heat from safety-class structures, systems and components and

transfer it to a heat sink such that:

1. Thermal, hydraulic and mechanical parameters are within design limits for the cooling system,

fusion device, confinement barriers and other safety-class equipment.

2. The cooling system provides and maintains a leaktight barrier against uncontrolled release of

fusion ash and radioactivity to the environment.

The cooling systems should comply with these criteria for normal operations, anticipated off-normal

events, and design basis accidents, assuming a worst-case single failure.

Potential System Safety Functions

Cooling system functions credited in the facility safety analysis in order to meet prescribed safety

criteria should be designated safety functions. Potential safety functions for cooling systems include:

Normal Operation, Shutdowns and Anticipated Off-normal Events

1. Remove heat from safety-class structures, systems and components to maintain temperatures

within design limits. For shutdown conditions, to the extent practical, heat removal should be

passive and require no human intervention.

2. Transfer the combined heat load to a safety-class heat sink. For shutdown conditions, to the

extent practical, transfer of heat to a heat sink should be passive and require no human

intervention.

3. Confine radioactivity entrained or deposited in the coolant system, and provide for suitable

releases to environment or transfer to a waste facility.

4. Detect, measure and isolate leaks or breaks in the coolant system pressure boundary.

5. Provide makeup coolant for small breaks or leaks in the cooling system pressure boundary.

Maintenance

Maintenance of the cooling system maintenance will normally occur during shutdown of the fusion

device. Portions of the cooling system may, however, receive maintenance during normal operations.

Whether maintenance occurs in normal operation or in a shutdown condition, the cooling system will

have the following safety functions.

1. Remove heat from safety-class structures, systems and components to maintain temperatures

within design limits. For shutdown conditions, to the extent practical, heat removal should be

passive and require no human intervention.