Geographic Applicability

DOE-STD-1024-92

the ratio of mean to median hazard for other estimates of ground motion

(response velocity). The actual numerical values chosen for the hazard

ratios and slopes were based on all eastern reactor site LLNL and EPRI

data as described in Appendix E.

GEOGRAPHIC APPLICABILITY

(LLNL-8, LLNL-14, LLNL-15, RF-1, RW-6)

The Standard has been revised to address issues related to geographic

applicability and the existence of only one or neither of the LLNL and EPRI

hazard curves at DOE sites.

This Standard explicitly applies to all DOE sites east of about 104W. The

Rocky Flats Site is excluded from the Standard because the LLNL and

EPRI studies did not extend far enough westward to provide the necessary

seismic hazard input. The Paducah, Kentucky site is excluded because

this site is in close proximity to the New Madrid, Missouri seismic zone

which should be modeled as an extended line source. Neither the LLNL or

EPRI studies adequately model the New Madrid source in this fashion. The

Paducah site has undertaken appropriate probabilistic seismic hazard

studies including extended source modeling for New Madrid.

Table 4 has been added to the Standard which displays the recommended

position for DOE sites which have existing LLNL and EPRI data. Table 4

also lists the remaining Eastern United States DOE sites. The SWG is

unaware of whether LLNL or EPRI data exists for these sites and thus

continues to recommend the use of TERA, Inc. results.

The revised Standard continues to suggest using the Newmark and Hall

Spectra.

RECOMMENDATION BY ONE ORGANIZATION

(LLNL-10)

The purpose of the Standard is to define the acceptable peak acceleration

values for DOE EUS sites. The updating of site-specific seismic hazard

curves should await the outcome of the joint DOE/NRC/EPRI seismic

hazard resolution efforts. For DOE EUS sites which have not calculated

the seismic hazard using the LLNL and/or EPRI methods, the TERA, Inc.

seismic hazard curves should continue to be used.

10.

OTHER WAYS OF DEVELOPING PSEUDO-MEANS

(LLNL-17, EM-3, RW-3)

The comments correctly point out that other approaches could also be

developed for combining the LLNL and EPRI results. The establishment of

"pseudo-means" for each study separately using the procedure outlined

and then averaging these two "pseudo-means" would result in about the

same position as that developed in the Standard. The LLNL "pseudo-

mean' would be the larger of the two simply reflecting the difference in the

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