Methods of Analysis

DOE-HDBK-6004-99

3. Methods of Analysis

The method of analysis should depend on the performance category and loads being considered.

Some of the methods are described in (ASCE 80). Elastic system analysis methods may be adequate

for lower performance categories whereas for higher performance categories inelastic analysis

methods nay be required. Guidelines to seismic analysis are available in (DOD 86). Dynamic seismic

structural analysis may be performed for predicted ground motions based on geotechnical site specific

information including variability using response spectra or time history. For large embedded

structures, soil structure analysis may be considered.

4. Acceptance Criteria

For lower performance categories, and for normal operations damage should be limited so that

hazardous materials can be controlled and confined, occupants are protected, and functions are not

interrupted. Thus damage should typically be limited in confinement barriers, ventilation systems and

filtering, and monitoring and control equipment.

For the higher performance categories, and for unlikely events, structures should be permitted to

undergo limited inelastic deformations without unacceptable damage when subjected to transient

loads. Energy absorption factors may be used to achieve appropriate conservatism in the design or

evaluation process. Stability and other post yield behavior criteria should be met.

For extremely unlikely events risk analysis should be performed to determine the extent of permissible

damage.

In design approaches where ductility and inelastic energy absorption are taken benefit of, attention

should be paid to the design details and quality assurance.

For all performance categories deformations expected from design load combinations should be able

to be withstood. If concrete is used as a pressure boundary, inelastic energy absorption should not

be considered.

5. System Interaction Effects

Any SSC whose structural failure could impact the function of SSC of a higher performance category

SSC are evaluated for interactions. To account for adverse interactions, a determination of failure

probability of an SSC given a postulated failure in the lower performance category is required.

HVAC

The application of design criteria from codes and standards for systems and components should be

applied in a graded approach relative to the significance of the safety function. For safety-class

systems and components, the design requirements of ASME AG-1 (ASME 93b) or a comparable

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

be applied (ASME 89a and ASME 89b). For non safety-class systems and components, codes and

standards for industrial and commercial grade application should be applied. Some of the major

HVAC components that should have a graded approach application of codes and standards are fans,

dampers, ductwork, filters and filter housings and instrumentation and controls.