Oklo: fast reactor technology?

Oklo is a next-generation nuclear company, based in California, recently going public via SPAC at a $850M valuation, backed by Sam Altman, of Y-Combinator and OpenAI fame. Oklo’s fast reactor technology absorbs high-energy neutrons in liquid metal and targets ultimate costs of $4,000/kW and 4c/kWh. What details can we infer from assessing Oklo’s patents, and can we de-risk the technology in our roadmap to net zero?

Oklo was founded in 2013, is headquartered in California, and has c50 employees. Sam Altman, of Y-Combinator and OpenAI fame, has been the Chairman of Oklo since 2015 and is CEO of the acquisition company, AltC, which has taken Oklo public via SPAC, with a listing on NYSE, while also raising $500M, at a valuation of $850M.

The company is named in homage to the Oklo mine in Gabon, where rock samples from 1972 uniquely seemed to show small quantities of U-235 naturally fissioning in the Earth’s subsurface, probably because of groundwater acting as a moderator.

Oklo plans to commercialize a liquid metal fast reactor, called the Aurora powerhouse, with 15MWe of power, using a mixture of recycled nuclear fuel and fresh fuel. It is also developing a 50MWe solution.

Illustration of the structural elements in Oklo's fast reactor.

In 2023/24, its published targets envisaged starting up a plant in the 2026/27 timeframe, which would be one of the soonest of the next-gen nuclear concepts we have screened.

The 15MWe plant is ultimately envisioned to cost “less than $60M” (versus $2-5bn for 300-1,000MW alternatives). This equates to less than $4,000/kWe. Including investment tax credits, Oklo materials thus see LCOEs for carbon-free baseload potentially as low as 4c/kWh. Numbers can be stress-tested in our nuclear cost model.

In April-2024, Diamondback Energy also agreed a 20-year PPA to procure 50MW of emission-free electricity for its operations in the Permian Basin.

Hence can we de-risk Oklo’s fast reactor technology, based on its patents? What details can we infer from the patents? (chart above). How does the patent library look on our usual patent assessment framework? And what challenges are we considering in our risking of this technology to meet new loads such as data-centers and as part of our roadmap to net zero?

Oklo’s design is a liquid metal fast reactor, a small, prefabricated, non-pressurized liquid-metal-cooled fast reactor, moving beyond the ‘light water reactors’ used for most nuclear plants historically. Specifically, this means it harnesses energy from fast neutrons, each with >1MeV of energy, as generated from fission, without using water or graphite moderators to slow them down to the 0.025eV energy level that promotes fission.

Instead, fast neutrons are reflected back within the reactor core, absorbed directly as heat in liquid metal, and can also breed more fissile isotopes (as opposed to light water reactors that only tend to use c5% of their nuclear fuel). Specific details can be guessed based on Oklo’s patents.

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