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Landfill Design Ground Motion at the Paducah Gaseous Diffusion Plant (Central United States)

Description: 

The Paducah Gaseous Diffusion Plant, a Superfund site near Paducah, Kentucky, in the central United States, is a former uranium enrichment plant owned by the U.S. Department of Energy (DOE). Due to its proximity to the New Madrid Seismic Zone, ground motion hazard is a concern for the site’s waste disposal facilities related to site cleanup, such as the landfill and the CERCLA disposal cell. Site effect is also a concern because the site sits on thick sediments (about 100 m) over hard Paleozoic bedrock. The Environmental Protection Agency regulation (Title 40) requires that the maximum expected horizontal acceleration with a 90 percent or greater probability that the acceleration will not be exceeded in 250 years, or the acceleration based on a site-specific seismic risk assessment, is considered for the landfill seismic design. The acceleration with a 90 percent or greater probability that the acceleration will not be exceeded in 250 years is equivalent to the acceleration with a 2 percent probability of exceedance in 50 years or 2,500-year return period. A probabilistic seismic hazard analysis (PSHA) conducted for the site in 1999 resulted in a peak horizontal ground acceleration (PGA) of 0.80g on top of rock and 0.51g on the surface with a 2,500-year return period. These high estimated accelerations made it difficult for the U.S. DOE to obtain a permit from the federal and state regulators to construct a landfill or CERCLA cell at the site. A deterministic seismic hazard analysis (DSHA) was conducted for the site in 2010 and resulted in a PGA of 0.36g on top of rock and 0.33g on the surface. The federal and state regulators accepted the PGA of 0.33g on the surface for seismic design of the landfill at the Paducah Gaseous Diffusion Plant in 2012. We will present a brief history of seismic hazard assessment for the Paducah Gaseous Diffusion Plant and discuss the strengths and weaknesses of PSHA and DSHA for developing design ground motions for critical facilities and infrastructure.

Session: Assessing Seismic Hazard for Critical Facilities and Infrastructure – Insights and Challenges - I

Type: Oral

Date: 5/3/2024

Presentation Time: 02:15 PM (local time)

Presenting Author: Zhenming

Student Presenter: No

Invited Presentation: 

Authors