Powering the Future with LCI Expertise
Lettis Consultants International (LCI) supported TerraPower’s Natrium Demonstration Project in Wyoming by performing a Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 project to evaluate seismic ground motions for use in nuclear design and licensing. The Natrium Demonstration project will be a milestone in advanced nuclear energy development. Featuring a 345 MW sodium-cooled fast reactor and a molten salt-based energy storage system, this innovative facility will deliver up to 500 MW of power on demand, enough to serve 400,000 homes. By integrating energy storage with nuclear technology, the Natrium system supports a resilient, low-carbon grid and complements renewable energy sources.
The Natrium reactor is part of a new generation of Small Modular Reactors (SMRs) — compact, scalable nuclear systems designed to deliver safe, flexible, and carbon-free energy.
LCI: Driving Technical Leadership in Seismic Safety
A project of this scale and significance demands uncompromising attention to safety—and that’s where LCI delivers unmatched value. Our team led the development of a Probabilistic Seismic Hazard Analysis (PSHA) for the Kemmerer Unit 1 plant in Wyoming using the Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 methodology. This process is specifically designed to quantify and document uncertainty and expert judgment in PSHA.
Grounded in Expertise: The LCI Team
LCI experts held key roles throughout the SSHAC process:
· Participatory Peer Review Panel – Dr. William Lettis (chair)
· Project Technical Integrator – Mr. Ivan Wong
· Technical Project Manager – Mr. Scott Lindvall
· Seismic Source Characterization (SSC) Lead – Dr. Ross Hartleb
· Ground Motion Characterization (GMC) Lead – Dr. Gabriel Toro
· Hazard Analyst – Dr. Andrew Seifried
· Database Manager – Mr. Serkan Bozkurt
Comprehensive Site Evaluation for a Cleaner Future
Comprehensive Site Evaluation for a Cleaner Future
For TerraPower’s Kemmerer Unit 1 plant near Kemmerer, WY, LCI and other industry experts developed Seismic Source Characterization (SSC) and Ground Motion Characterization (GMC) models. These were then used to calculate rock hazard curves before performing a Site Response Analysis—a key step in evaluating how local conditions amplify seismic ground motion. The results contributed directly to engineering response spectra, which feed into structural design and safety evaluations.
LCI’s seismic hazard and other geologic work formed part of the Preliminary Safety Analysis Report (PSAR), which TerraPower submitted to the U.S. Nuclear Regulatory Commission (NRC) for review. LCI assisted TerraPower in preparing portions of the PSAR and helped respond to technical questions from the NRC. On March 4, 2026, the NRC issued TerraPower a Construction License for the Kemmerer Unit 1 plant.
Trusted Partner in Regulatory Compliance
With a strong track record in regulatory compliance and licensing support, LCI helps clients navigate complex technical and procedural challenges. Our seismic hazard, site response, and risk assessment capabilities are deeply rooted in decades of experience and a culture of scientific integrity.