Figure C-6 Earthquake Provision Basic Approach

DOE-STD-1020-2002

Performance Category 2 and Lower SSCs

Performance Category 3 and Higher SSCs

International

Use Graded

Building Code

Approach From

2000

Nuclear Power Plants

Equivlent Static or Dynamic Analysis Scaled Dynamic Analysis Generally Performed

to IBC Type Base Shear

Figure C-6 Earthquake Provision Basic Approach

The International Building Code (IBC 2000) has been followed for Performance

Categories 1 and 2 because it is only current model building code meeting NEHRP provisions .

The Interagency Committee on Seismic Safety in Construction (ICSSC) has concluded that the

following seismic provisions are substantially equivalent:

1) International Building Code, IBC 2000 (Ref. C-28)

2) 1997 NEHRP Recommended Provisions (Ref. C-68)

3) ASCE 7-98

The other model building codes may be followed provided site-specific ground motion data is

incorporated into the development of earthquake loading similar to the manner described in this

document for the IBC 2000.

For Performance Category 3 and 4 SSCs, these seismic design and evaluation criteria

specify that seismic evaluation be accomplished by dynamic analysis (see Table C-7). The

recommended approach is to perform an elastic response spectrum dynamic analysis to evaluate

elastic seismic demand on SSCs. However, inelastic energy absorption capability is recognized

by permitting limited inelastic behavior. By these provisions, inelastic energy absorption

capacity of structures is accounted for by the parameter, F. Elastically computed seismic

response is reduced by F values ranging from 1 to 3 as a means of accounting for inelastic

energy absorption capability for more hazardous facilities. F values are much lower than R

values increasing the risk reduction ratio, RR. By these provisions, only the element forces due

to earthquake loading are reduced by F. This is a departure from the DOD manual (Ref. C-5)

C-20