Google commits to buying power generated by nuclear-energy startup Kairos Power

Based on the headline I thought that this was an enormous capital commitment for an enormous generating capacity, but the deal is with a company called Kairos that is developing small modular reactors with 75 megawatts of electrical output each [1]. 7 reactors of this type, collectively, would supply 525 megawatts (less than half of a typical new commercial power reactor like the AP1000, HPR1000, EPR, or APR1400).

Kairos is in a pretty early stage. They started building a test reactor this summer, scheduled for completion by 2027:

https://www.energy.gov/ne/articles/kairos-power-starts-const...

EDIT: Statement from the official Google announcement linked by xnx below [2]:

Today, we’re building on these efforts by signing the world’s first corporate agreement to purchase nuclear energy from multiple small modular reactors (SMRs) to be developed by Kairos Power. The initial phase of work is intended to bring Kairos Power’s first SMR online quickly and safely by 2030, followed by additional reactor deployments through 2035. Overall, this deal will enable up to 500 MW of new 24/7 carbon-free power to U.S. electricity grids and help more communities benefit from clean and affordable nuclear power.

[1] https://kairospower.com/technology/

[2] https://news.ycombinator.com/item?id=41841108

Would be extremely interesting to the the $/MWh for the deal to understand the viability.

Otherwise similar to the NuScale deal which fell through last autumn.

A PPA like agreement which then only kept rising until all potential utilities had quit the deal.

All honor to Kairos if they can deliver, but history is against them. Let’s hope they succeed.

> NuScale has a more credible contract with the Carbon Free Power Project (“CFPP”) for the Utah Associated Municipal Power Systems (“UAMPS”). CFPP participants have been supportive of the project despite contracted energy prices that never seem to stop rising, from $55/MWh in 2016, to $89/MWh at the start of this year. What many have missed is that NuScale has been given till around January 2024 to raise project commitments to 80% or 370 MWe, from the existing 26% or 120 MWe, or risk termination. Crucially, when the participants agreed to this timeline, they were assured refunds for project costs if it were terminated, which creates an incentive for them to drop out. We are three months to the deadline and subscriptions have not moved an inch.

https://iceberg-research.com/2023/10/19/nuscale-power-smr-a-...

> All honor to Kairos if they can deliver, but history is against them.

History is not really against them. Our current reactors (mainly pressurized water reactors) are the way they are because Admiral Rickover determined that PWRs are the best option for submarines. He was not wrong, but civilian power reactors are not the same as the reactors powering submarines.

PWRs are expensive mainly because of the huge pressure inside the reactor core, about 150 times higher than the atmospheric pressure. For comparison, a pressure cooker has an internal pressure about 5 times higher than the atmospheric pressure, and such a cooker can explode with a pretty loud bang.

The Kairos Hermes reactor design is based on a design that was tested in the '60s, the Molten-Salt Reactor Experiment [1]. While such a reactor can be used to burn thorium, Kairos decided to go with the far more conventional approach of burning U-235. The reactor operates at approximately regular atmospheric pressure. This should reduce considerably the construction costs.

Of course, there are unknowns. While the world has built thousands of pressurized water reactors, it has built maybe 10 molten salt reactors. For example one quite unexpected effect in the MSRE was the enbrittlement of the reactor vessel caused by tellurium, which shows up as a fission product when U-235 burns.

The Nuclear Regulatory Commission is a very conservative organization, and they don't have much experience with molten salt reactors because nobody has. It took them 6 years to give NuScale an approval for a pressurized water reactor, design that they knew in and out. My guess is that they will not give Kairos an approval without at least 15 years of testing. But Google's agreement with Kairos is quite crucial to keep this testing going.

[1] https://en.wikipedia.org/wiki/Molten-Salt_Reactor_Experiment

> The Nuclear Regulatory Commission is a very conservative organization

I'm glad they are, actually! Personally, I'm not really convinced by the "small modular reactor" concept. Ok, so building a big nuclear power plant is expensive. But is it really cheaper to build 10 smaller nuclear power plants (which all need to conform to the same safety regulations, need maintenance, personnel etc.) instead?

I firmly believe that iteration is the key to good engineering. SpaceX has got where they are (partly) due to running flight after flight with incremental improvements each time. The problem with the massive reactors is that you get to build only a couple of them, so you never get to take advantage of learnings to make the next one better/cheaper/quicker.