Appendix B: Interim Guidance For The Development of Deterministric Spectral Shape

DOE-STD-1024-92

Appendix B

INTERIM GUIDANCE FOR THE DEVELOPMENT OF

DETERMINISTIC SPECTRAL SHAPE

UCRL-15910 (DOE-STD-1020) specifies that median response spectral shapes

should be associated with the Design Basis earthquake (DBE). UCRL-15910

(DOE-STD-1020) states that the spectral shapes recommended by TERA, Inc.

can be used for the DBE. The TERA, Inc. spectral shapes, like the TERA, Inc.

probabilistic hazard curves, are relatively old and do not represent the current

state-of-the-art. Site-specific spectral shapes can be used to determine if the

TERA spectral shape is unconservative. The discussion provided below

provides guidance regarding the development of site specific spectral shapes.

The Office of Nuclear Energy is developing a Department of Energy (DOE)

Standard related to DBE response spectra which will supersede the interim

guidance provided below (Draft Standard DOE-STD-1023).

For, those sites who choose to develop a deterministic site-specific spectral

shape, information contained in the probabilistic seismic hazard analysis should

be used to establish the appropriate magnitude and distance. This will require

that the dominant earthquake source(s), magnitude(s) and distance(s) be

determined. Such an analysis should be completed for both the peak ground

acceleration and for a lower frequency best associated with the maximum

spectral velocity (in the 1 to 5 hertz frequency range). Thus, this will require the

use of the Uniform Hazard Spectra. The recommended steps to complete this

analysis are outlined below:

At the probability of interest (i.e., 2 x 10E-4 for high hazard

facilities) determine the dominant magnitudes (M's) and distances

(R's) for peak ground acceleration (PGA) and maximum spectral

velocity (MSV). For example:

PGA: M(l); R(l)

MSV: M(2); R(2)

It is recommended that the stability of the M:R combinations be

assessed at other probabilities (such as 5 to 10 times lower than

the probability of interest) given the issues raised with the

Uniform Hazard Spectra, which are described in the text of the

Standard.

Both Lawrence Livermore National Laboratory and Risk

Engineering Incorporated have available methods (codes) which

can be used to determine the dominant M and R.

Develop the (deterministic) median response spectra for each M:R

combination: For example M(I)R(l) median spectra and M(2)R(2) median

spectra. Guidance can be found in U.S. Nuclear Regulatory Commission

B-1