Additional Requirements

DOE-STD-1020-2002

2.4

Additional Requirements

2.4.1 Equipment and Distribution Systems

For PC-1 and PC-2 systems and components, the design or evaluation of equipment or

non-structural elements supported within a structure may be based on the total lateral seismic

force, Fp, given by the IBC provisions (Ref. 2-7). For PC-2 equipment expected to remain

functional during or after earthquake, testing or experience based data for such equipment shall

be an additional qualification requirement. For PC-3 and PC-4 systems and components, seismic

design or evaluation shall be based on dynamic analysis, testing, or past earthquake and testing

experience data. In any case, equipment items and non-structural elements must be adequately

anchored to their supports unless it can be shown by dynamic analysis or by other conservative

analysis and/or test that the equipment will be able to perform all of its safety functions without

interfering with the safety functions of adjacent equipment. Anchorage must be verified for

adequate strength and sufficient stiffness.

Evaluation by Analysis

By the IBC provisions for PC-1 and PC- 2, parts of the structures, permanent non-

structural components, and equipment supported by a structure and their anchorages and

required bracing must be designed to resist seismic forces. All the provisions of the IBC () shall

be followed for PC-1 & PC-2 SSCs.

The lateral force determined using IBC 2000 shall be distributed in proportion to the

mass distribution of the element or component. Forces determined shall be used for the design

or evaluation of elements or components and their connections and anchorage to the structure,

and for members and connections that transfer the forces to the seismic-resisting systems.

Forces shall be applied in the horizontal direction that results in the most critical loadings for

design/evaluation.

For PC-3 and PC-4 subsystems and components, support excitation shall be calculated by

means of floor response spectra (also commonly called in-structure response spectra). Floor

response spectra should be developed accounting for the expected response level of the

supporting structure even though inelastic behavior is permitted in the design of the structure

(see Section 2.3.3). It is important to account for uncertainty in the properties of the equipment,

supporting structure, and supporting media when using in-structure spectra which typically have

narrow peaks. For this purpose, the peak broadening or peak shifting techniques outlined in

ASCE 4 shall be employed.

Equipment or distribution systems that are supported at multiple locations throughout a

structure could have different floor spectra for each support point. In such a case, it is acceptable

to use a single envelope spectrum of all locations as the input to all supports to obtain the inertial

loads. Alternatively, there are analytical techniques available for using different spectra at each

support location or for using different input time histories at each different support.

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