DBE Response Spectra Acceptance Criteria

DOE-STD-1023-95

hazard methodology and input parameters. The review should be documented including questions

raised by reviewers and resolutions provided by the analyst.

3.1.3 DBE Response Spectra Acceptance Criteria

The target DBE response spectrum may be defined as the mean uniform hazard response spectrum

(UHS) associated with the seismic hazard annual probability of exceedance over the entire frequency

range of interest. The slope of the seismic hazard curve is also an important consideration when

using the DBE for structural analysis (see DOE STD-1020-2002).

The target DBE response spectra should be reviewed to ensure its adequacy. Recommendations for

spectral shapes as functions of magnitude, distance from the seismic source and site conditions are

presented in McGuire, et. al. (2001) and should be considered in this evaluation.

Earthquake vibratory ground motions to be used as input excitation for design and evaluation of

DOE facilities, according to DOE-STD-1020-2002, is defined using an approach similar to that

developed by the United States Nuclear Regulatory Commission (see Regulatory Guide 1.165,

1997). When site-specific response spectra are unavailable, a median standardized spectral shape

may be used so long as such a spectrum shape is either reasonably consistent with or conservative for

the site conditions. In these cases the median spectral shape should be scaled to the mean ground

motion parameters based on the Uniform Hazard Spectrum to produce an appropriate DBE spectra.

The final DBE ground motion at the site shall be specified in terms of smooth and broad frequency

content horizontal and vertical response spectra defined at a specific control point. The control point

is typically defined at the bedrock outcrop, at the top of ground or at some intermediate surface. The

selection of the appropriate control point depends upon the details of the seismic response analysis to

be performed for the facility. The method to transfer the DBE spectra from one depth of the site to

another must adequately account for the effects of the primary contributors to the seismic hazard on

all aspects of site response.

Acceptable methods for the development of site-specific response spectra are described in Section

3.1.3.1 of this Standard. Alternatively, methods commonly used for the development of standardized

response spectra based on general site conditions instead of a site-specific geotechnical study are

described in Section 3.1.3.2 of this Standard.

3.1.3.1 Site-Specific DBE Response Spectra

The procedure described in this Section for developing a median site-specific spectral shape is

applicable for facilities with SSCs in Performance Category 3 or 4. In accordance with the graded

approach, the development of site-specific spectral shapes for facilities with SSCs in Performance

Category 3 may be relatively less rigorous than those in Performance Category 4.

For those sites that choose to develop a site-specific spectral shape, information contained in the

probabilistic seismic hazard analysis shall be used to establish the appropriate magnitudes and

distances for the controlling (or dominant) earthquakes. Controlling earthquakes are those potential

earthquakes that could cause the greatest or governing ground motions at a site. There may be