US-based Oklo has signed a preferred supplier agreement with Siemens Energy for the power conversion system of its Aurora powerhouse. Oklo said that, building on a previously signed memorandum of understanding, this binding agreement marks a crucial step in its vision to enhance production scalability, cost efficiency, and rapid deployment to meet growing customer demand.
Oklo is developing the Aurora microreactor, a liquid-metal-cooled fast reactor, which uses heat pipes to transport heat from the reactor core to a supercritical carbon dioxide power conversion system to generate electricity. It will use HALEU fuel. Oklo says the reactor builds on the Experimental Breeder Reactor-II (EBR-II) and space reactor legacy. EBR-II features a hexagonal fuel element with a sealed heat pipe and a passive air-cooling system. Oklo initially marketed a 1.5 MWe microreactor version of the Aurora, but has now expanded its capacity offerings from 15 MWe to 100 MWe.
Siemens Energy is a supplier of steam turbine and generator technology – rotating equipment that is part of the conventional island in small and large nuclear generation plants. Siemens Energy will supply the power conversion and supporting systems, fostering efficiencies through economies of scale. Standardising equipment across Oklo’s powerhouses is expected to result in cost savings in manufacturing, construction, operations, and maintenance. Utilising shared spare parts across deployment is expected to reduce maintenance downtime, enhance reliability, and improve overall performance.
“We prioritise cost in our engineering process to fully leverage the advantages of fast fission technology,” said Jacob DeWitte, Oklo’s co-founder and CEO. “Our technology is based on proven designs, allowing us to utilise small, prefabricated, and non-pressurised components made from readily available materials and existing supply chains, further reducing costs and complexity.”
Oklo claims “robust customer engagement exceeding 1,300 megawatts in non-binding letters of intent” and says the partnership sith Siemens “underscores Oklo’s market traction and strategic focus on commercialisation. “We are committed to delivering advanced fission clean energy solutions that are both innovative and economically viable,” said Alex Renner, Oklo Chief Product Officer.
Oklo received a site permit in 2019 from the US Department of Energy (DOE) to build its first Aurora facility at Idaho National Laboratory (INL). In 2020, Oklo submitted a combined licence application to the Nuclear Regulatory Commission (NRC) to build and operate the Aurora microreactor at INL. However, NRC denied the application, citing the company’s failure to provide sufficient design information. A revised application was submitted in September 2022. The company is developing advanced fuel recycling technologies in collaboration with DOE and US National Laboratories.
