Loads

DOE-STD-6003-96

2. Pressure load--The pressure load should include the full range of credible internal

and external pressures during normal operations and off-normal events including

design-basis events. Additionally, the pressure load range should include

temperature-induced pressures, hydrostatic or pneumatic test pressures, and any

credible pressure augmentation resulting from small leaks between two coupled

systems.

3. Thermal load--The thermal load should include transient thermal loads as well as the

temperature distribution during bakeout and wall conditioning.

4. Electromagnetic loads--Electromagnetic loads induced during operation of the device

are experienced as a result of currents in the component under evaluation interacting

with external magnetic fields. Loads should include the electromagnetic effects of dis-

charge cleaning where appropriate.

5. Electromagnetic loads during faults--Electromagnetic loads should include those

induced during off-normal operating events such as control failures, power supply fail-

ures, bus opens or shorts, or magnet faults.

6. Disruption/VDE loads--Disruption/VDE loads are any thermal or electromagnetic

loads induced in the component due to loss of control of the plasma. A range of

plasma motions and current behaviors should be considered to determine the worst

case events. Analysis should include conservative assumptions for event amplitude,

time scale, and event frequency.

7. Interaction loads--Interaction loads are loads imposed on the component by other

adjacent systems or components during normal or off-normal conditions. For exam-

ple, a magnet failure may result in a nonsymmetrical load distribution in the magnet

support structure that could cause deflections resulting in an additional load transmit-

ted to adjacent vacuum vessel structure.

8. Natural phenomena hazard loads--Natural phenomena hazard loads are site-specific

loads due to earthquakes, wind, floods, and so on. Guidelines for methods of estab-

lishing load levels on facilities from natural phenomena hazards and for methods of

evaluating the behavior of structures and equipment to these load levels are con-

tained in DOE 1993b, DOE 1993c, DOE 1994b, DOE 1995a, and DOE 1995b.

9. Off-normal event loads--Component internal and external loading from credible off

normal events, including design-basis events, should be considered as appropriate.

The SSC structural design evaluations will be based on predicted responses for concurrent

event load combinations that are compared against the corresponding allowable stresses. In

applications involving the ASME Code, for example, the evaluation load combinations would be

performed in a conservative manner using design-basis event propagation assumptions in the

facility safety analysis. Service levels defined in ASME 1992 to be used in the structural design

process should also be assigned using information derived from the safety analysis process.