Kairos Power’s Post

When a 4.1 magnitude earthquake shook Knoxville last weekend, it was a timely reminder of the importance of seismic safety considerations in nuclear reactor design.  The Nuclear Regulatory Commission requires that all safety-related systems, structures, and components for U.S. reactors must be designed according to the most severe natural phenomena historically reported for the site and surrounding area. That’s why the Hermes demonstration reactor, currently under construction in Oak Ridge, is designed to withstand site-specific, earthquake-induced ground motion.  When things started shaking on Saturday, the two drilled piers that we had placed for the Hermes foundation days before remained sound. The piers go down roughly 40 feet, anchoring the structure to bedrock.  In addition to a sturdy foundation, the Hermes reactor building will be seismically isolated to minimize the force and potential displacement from seismic events. Two weeks ago, the Kairos Power team was in Pavia, Italy, to observe a test of the Visco-Dampers that will be part of Hermes' Seismic Isolation System – a successful collaboration between the Kairos Power Civil Structures and Quality Assurance teams, Simpson Gumpertz & Heger (SGH), GERB USA, and EUCENTRE.  We are also collaborating with the PEER - Pacific Earthquake Engineering Research Center (PEER) to validate seismic models of Hermes' reactor vessel and internals. The KP-PEER team recently completed a quality level shake-table test to generate data that will support the Hermes Operating License Application, ensuring the reactor’s safe operation under all environmental conditions.   So, the next time you feel the ground moving, rest assured. The Hermes reactor is designed to withstand relevant earthquake hazards.