Bay City, TX

South Texas Project Nuclear Power Plant, Units 3 & 4


The South Texas Project is a twin-reactor facility that produces 2,700 MW of power.  To increase the power generating capacity, the plant planned to add two advanced boiling water reactors to the existing pressurized water reactors.  SGH and Sargent & Lundy performed advanced analyses in support of the Combined Operating License Application (COLA).

The South Texas Plant is located on a deep soil site with shear wave velocity of less than 1,000 ft/s that requires seismic analysis confirmation in accordance to Nuclear Regulatory Commission for Combined Operation License Applications.

As part of this work, SGH and Sargent & Lundy performed confirmation soil-structure interaction (SSI) analyses for the Design Control Documents, low shear wave velocity seismic SSI analyses, and site specific SSI analyses.  We performed the following analyses:

  • SSI analyses for DCD models and low shear wave velocity seismic SSI analyses for the following:
    • Nuclear Island, including Reactor and Control Buildings
    • Structure-soil-structure interaction of Reactor, Control and Turbine Buildings
  • Site specific seismic SSI analyses of the following:
    • Nuclear Island, including Reactor Building and Control Building
    • Ultimate heat sink and pump room
    • Crane wall and nuclear island seismic structure-structure interaction
    • Diesel Generator Fuel Oil Storage (DGFOS) vaults
    • Reactor Service Water (RSW) tunnel
    • Structure-soil-structure interaction of ultimate heat sink pump house building, the RSW tunnel, DGFOS vaults and Reactor Building
    • Structure-soil-structure interaction of Reactor Building, RSW tunnel and Radwaste building

Project Summary



Completion Date
New Construction
Structures | Advanced Analysis
Science & Defense
Sargent & Lundy LLC
Specialized Capabilities
Seismic Engineering | Nuclear

Key team members

Frank Kan
Frank Kan
Said Bolourchi
Said Bolourchi
Senior Principal