Cyclic Loading

DOE-HDBK-6004-99

Cyclic Loading

The vacuum vessel and its supports are subject to cyclic loading during normal operations. Thermal

cycling and unavoidable plasma disruption loads are expected. The necessity of a fatigue analysis

should be evaluated based on the criteria of ASME 93 or comparable safety-related code using

conservative values for variables such as number of pulses, percentage of pulses that have disruptions,

and service life including expected changes in material properties with time. Cyclic loading must be

defined on load/time diagrams so that a fatigue analysis, if necessary, can be performed.

Structural Acceptance Criteria

Vacuum vessel

The vacuum vessel and its appendages should be designed, fabricated, inspected, and tested in

accordance with a recognized safety-related code such as the ASME Boiler and Pressure Vessel

Code. The design of the fusion facility components which is outside the scope of conventional codes

or standards due to design temperature, materials selection and/or any other design feature, should

meet the safety design criteria of this Fusion Safety Standard and should employ a design and analysis

methodology which is consistent with requirements of a recognized safety-related code.

Piping, Pumps and Valves

Piping, pumps and valves should be designed in accordance with relevant criteria in ASME 93 or a

comparable safety-related code.

Other

Hardware internal or adjacent to the vacuum vessel whose credible failure could impact the safety

function of the vacuum vessel should be classified as safety-class components or items.

Deflection Analysis

Vacuum vessel deflections should be calculated and analyzed to determine potential interferences and

to verify seal integrity.

Testing

Weld Inspection

Non-destructive examination should be performed in accordance with Section V of the ASME Boiler

and Pressure Vessel Code as modified by Section III, Article NC-5111 or approved equal. Non-

destructive test personnel qualification and weld acceptance criteria are found in Article NC-5000 of

the ASME Boiler and Pressure Vessel Code or approved equal.

Pressure Test

1. Vacuum Vessel - All vacuum vessels that provide a containment barrier should be leak checked

before initial operations and periodically thereafter and meet the requirements specified in the