US-based fission technology company Oklo has signed a memorandum of understanding (MOU) with Siemens Energy designating Siemens Energy to become Oklo’s preferred supplier for rotating equipment of the power conversion system (conventional island) for the Aurora powerhouse. Siemens Energy would also be positioned to provide consulting to support Oklo in design work of the conventional island. Oklo says that as a result of this partnership, the power generation equipment for its powerhouses is expected to be “cost-efficient, well-proven, and sourced from readily available components, enabling a key catalyst for deployment scale-up and reliability” of for its advanced fission power plants.

“The clean power generated by advanced nuclear is one of the key steps to reaching a net zero future and Siemens Energy’s thermal energy components and services complement the powerhouses being developed by Oklo,” said Tobias Panse, Senior Vice President of Industrial Steam Turbines and Generators at Siemens Energy. “Working with Oklo as a preferred supplier will bring us closer to advanced nuclear deployments and our net-zero targets.” Oklo said Siemens Energy's contributions will extend beyond the supply of steam turbine generators; they will also provide consulting to support the design and integration of the power conversion system (conventional island).

Oklo is developing the Aurora microreactor, 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.

Alex Renner, Senior Director of Product at Oklo said the company “is focused on providing clean, reliable, affordable power to customers” He added: “Fast fission reactors are a proven technology to produce heat and partnering with Siemens Energy takes steps to secure an efficient, reliable, and scalable supply chain for converting that heat into power in our Oklo Aurora powerhouses.”

By partnering with Siemens Energy, a global leader in energy technology, Oklo says it will gain access to a well-established supply chain for its essential components critical to making power. The partnership with Siemens Energy as a proven leader in energy solutions would complement Oklo’s overall design philosophy for the powerhouses, “which is based on proven fast reactor technology with hundreds of reactor years of successful operational history”.

Currently however, the only operational fast reactors are in Russia, which is the world leader in this technology. A number of other countries in the past have run fast reactor prototypes, such as EBR-II in the US, Phénix and Superphénix in France, the Prototype Fast Reactor and Dounreay Fast Reactor in the UK and Joyo and Monju in Japan. These were all closed down prematurely for a combination of political and technical reasons, with only the Russian development continuing.

Image: Oklo’s Senior Director of Product, Alex Renner, and Oklo's Director of Power Engineering, Scott Auerbach, engage in a discussion of the industrial steam turbine package with the Siemens Energy team (courtesy of Oklo)