Earthquake Ground Motion Response Spectra

DOE-STD-1020-2002

of 1x10-4 in this standard is consistent with SSE levels. (See also U.S. NRC Regulatory Guide

1.165)

These seismic hazard definitions specified in this standard are appropriate as long as

the seismic design or evaluation of the SSCs for these earthquake levels is conservatively

performed. The level of conservatism of the evaluation for these hazards should increase as one

goes from PC-1 to PC-4 SSCs. The conservatism associated with Performance Categories 1 and

2 should be consistent with that contained in the IBC (Ref. C-28), or NEHRP (Ref. C-68) for

normal or essential facilities, respectively. The level of conservatism in the seismic evaluation

for Performance Category 4 SSCs should approach that used for nuclear power plants when the

seismic hazard is designated as shown above. In general for majority of DOE sites, the criteria

contained herein follow the philosophy of a gradual increase in the conservatism of the

evaluation procedures and acceptance criteria as one goes from Performance Category 1 to

Performance Category 4.

Figure C-4 Probability of Exceeding SSE Response Spectra

C.3.2

Earthquake Ground Motion Response Spectra

Design/evaluation Basis Earthquake (DBE) response spectra generally have the shape

shown in Figure C-3. The DBE spectrum shape is similar to that for an actual earthquake except

that peaks and valleys that occur with actual earthquake spectra are smoothed out. Also,

design/evaluation spectra typically include motions from several potential earthquakes such that

they are broader in frequency content than spectra computed for actual earthquake ground

C-15