Amazon-backed X-energy sweet talks investors into another $700M for small modular reactor dream
(2025/11/24)
- Reference: 1764011285
- News link: https://www.theregister.co.uk/2025/11/24/x_energy_700m_smr/
- Source link:
Amazon-backed nuclear energy startup X-energy says it has booked orders for 144 small modular reactors (SMRs) which will eventually deliver over 11 gigawatts of power, assuming that they actually get built. And investors continue to support this vision.
On Monday, X-energy [1]revealed that it had gotten Jane Street and a slew of other private equity firms to deliver a $700 million Series D funding round to keep the lights on while the startup waits for the Nuclear Regulatory Commission (NRC) to sign off on a four-unit deployment of its Xe-100 reactors at Dow's Seadrift Operations manufacturing site in Texas.
The Xe-100 is a fourth-generation high-temperature, gas-cooled reactor capable of producing 80 MW of power over its 60-year operational life. The startup claims the cash infusion will help to shore up its supply chains and attract new customers.
[2]
Nuclear power, and in particular SMRs, has become a hot topic amid the AI boom as power has increasingly become a bottleneck for datacenter expansion across the US and much of Europe.
[3]
[4]
You may recall that, late last year, Amazon [5]announced a $500 million investment in X-energy to deploy roughly 5 gigawatts' worth of miniaturized nuclear reactors across the US by 2039. Among the first of these will be the [6]Cascade Advanced Energy Facility in Washington state, which will supply "up to" 960 megawatts of clean energy when it comes online sometime in the 2030s.
The other 6 gigawatts of power will supposedly be [7]deployed in the United Kingdom as part of a collaboration with British energy and services firm Centrica. However, the reactors aren't expected to begin producing electricity until the "mid-2030s."
[8]
Fuel for the reactors comes in the form of TRISO-X fuel pebbles, which use high-assay low-enriched uranium that is encased in three densely packed layers of carbon. Hundreds of thousands of these pebbles are gravity fed through the reactor in a continuous loop.
These pebbles are cooled by a continuous flow of helium gas through the reactor core. Heat captured by the gas is then used to boil water to generate electricity.
[9]SC25 gets heavy with mega power and cooling solutions
[10]GPU goliaths are devouring supercomputing – and legacy storage can't feed the beast
[11]Britain's first small modular reactors to be built in Wales
[12]Amazon spills plan to nuke Washington...with X-Energy mini-reactors
X-energy is one of several SMR startups that have attracted the attention of major cloud and hyperscale customers in recent years. For example, Google is [13]betting on Kairos Power's TRISO fuel-based reactor design to eventually provide 500 megawatts' worth of carbon-free atomic power.
While both reactors use the same fuel pellets, Kairos relies on molten salt for cooling as opposed to helium gas. Kairos' first SMR, the Hermes 2 demonstrator, is slated to supply 50 megawatts to the local grid, including Google datacenters in Tennessee and Alabama, when it comes online in 2030.
And unlike X-energy, Kairos has actually received the NRC greenlight to begin construction of the reactors, though it'll still need additional approvals before switching them on.
[14]
Alongside Google and Amazon, Oracle plans to deploy at least three SMRs to power a gigawatt-scale datacenter, though who will provide them isn't clear. Meta, meanwhile, has signed a 20-year deal to revive a nuclear power plant in Illinois while Microsoft is financing the rehab of the Three Mile Island Unit 1 reactor — the one that didn't partially melt down — to support its own datacenter expansion. ®
Get our [15]Tech Resources
[1] https://x-energy.com/media/news-releases/x-energy-closes-oversubscribed-700-million-series-d-financing-round-to-continue-expansion-to-meet-global-energy-demand
[2] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2aSTjlXb8tPMrSxFD5RTKNgAAAEA&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[3] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aSTjlXb8tPMrSxFD5RTKNgAAAEA&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[4] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33aSTjlXb8tPMrSxFD5RTKNgAAAEA&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[5] https://www.theregister.com/2024/10/16/amazon_nuclear_smr/
[6] https://www.theregister.com/2025/10/17/amazon_nuke_washington/
[7] https://x-energy.com/media/news-releases/centrica-and-x-energy-sign-joint-development-agreement-to-deploy-uks-first-advanced-modular-reactors
[8] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aSTjlXb8tPMrSxFD5RTKNgAAAEA&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[9] https://www.theregister.com/2025/11/20/heavy_industry_invades_sc25/
[10] https://www.theregister.com/2025/11/14/evolving_supercomputers_hpc_ai_and/
[11] https://www.theregister.com/2025/11/13/anglesey_smr/
[12] https://www.theregister.com/2025/10/17/amazon_nuke_washington/
[13] https://www.theregister.com/2025/08/18/google_smr_datacenters/
[14] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33aSTjlXb8tPMrSxFD5RTKNgAAAEA&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[15] https://whitepapers.theregister.com/
On Monday, X-energy [1]revealed that it had gotten Jane Street and a slew of other private equity firms to deliver a $700 million Series D funding round to keep the lights on while the startup waits for the Nuclear Regulatory Commission (NRC) to sign off on a four-unit deployment of its Xe-100 reactors at Dow's Seadrift Operations manufacturing site in Texas.
The Xe-100 is a fourth-generation high-temperature, gas-cooled reactor capable of producing 80 MW of power over its 60-year operational life. The startup claims the cash infusion will help to shore up its supply chains and attract new customers.
[2]
Nuclear power, and in particular SMRs, has become a hot topic amid the AI boom as power has increasingly become a bottleneck for datacenter expansion across the US and much of Europe.
[3]
[4]
You may recall that, late last year, Amazon [5]announced a $500 million investment in X-energy to deploy roughly 5 gigawatts' worth of miniaturized nuclear reactors across the US by 2039. Among the first of these will be the [6]Cascade Advanced Energy Facility in Washington state, which will supply "up to" 960 megawatts of clean energy when it comes online sometime in the 2030s.
The other 6 gigawatts of power will supposedly be [7]deployed in the United Kingdom as part of a collaboration with British energy and services firm Centrica. However, the reactors aren't expected to begin producing electricity until the "mid-2030s."
[8]
Fuel for the reactors comes in the form of TRISO-X fuel pebbles, which use high-assay low-enriched uranium that is encased in three densely packed layers of carbon. Hundreds of thousands of these pebbles are gravity fed through the reactor in a continuous loop.
These pebbles are cooled by a continuous flow of helium gas through the reactor core. Heat captured by the gas is then used to boil water to generate electricity.
[9]SC25 gets heavy with mega power and cooling solutions
[10]GPU goliaths are devouring supercomputing – and legacy storage can't feed the beast
[11]Britain's first small modular reactors to be built in Wales
[12]Amazon spills plan to nuke Washington...with X-Energy mini-reactors
X-energy is one of several SMR startups that have attracted the attention of major cloud and hyperscale customers in recent years. For example, Google is [13]betting on Kairos Power's TRISO fuel-based reactor design to eventually provide 500 megawatts' worth of carbon-free atomic power.
While both reactors use the same fuel pellets, Kairos relies on molten salt for cooling as opposed to helium gas. Kairos' first SMR, the Hermes 2 demonstrator, is slated to supply 50 megawatts to the local grid, including Google datacenters in Tennessee and Alabama, when it comes online in 2030.
And unlike X-energy, Kairos has actually received the NRC greenlight to begin construction of the reactors, though it'll still need additional approvals before switching them on.
[14]
Alongside Google and Amazon, Oracle plans to deploy at least three SMRs to power a gigawatt-scale datacenter, though who will provide them isn't clear. Meta, meanwhile, has signed a 20-year deal to revive a nuclear power plant in Illinois while Microsoft is financing the rehab of the Three Mile Island Unit 1 reactor — the one that didn't partially melt down — to support its own datacenter expansion. ®
Get our [15]Tech Resources
[1] https://x-energy.com/media/news-releases/x-energy-closes-oversubscribed-700-million-series-d-financing-round-to-continue-expansion-to-meet-global-energy-demand
[2] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2aSTjlXb8tPMrSxFD5RTKNgAAAEA&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[3] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aSTjlXb8tPMrSxFD5RTKNgAAAEA&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[4] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33aSTjlXb8tPMrSxFD5RTKNgAAAEA&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[5] https://www.theregister.com/2024/10/16/amazon_nuclear_smr/
[6] https://www.theregister.com/2025/10/17/amazon_nuke_washington/
[7] https://x-energy.com/media/news-releases/centrica-and-x-energy-sign-joint-development-agreement-to-deploy-uks-first-advanced-modular-reactors
[8] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aSTjlXb8tPMrSxFD5RTKNgAAAEA&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[9] https://www.theregister.com/2025/11/20/heavy_industry_invades_sc25/
[10] https://www.theregister.com/2025/11/14/evolving_supercomputers_hpc_ai_and/
[11] https://www.theregister.com/2025/11/13/anglesey_smr/
[12] https://www.theregister.com/2025/10/17/amazon_nuke_washington/
[13] https://www.theregister.com/2025/08/18/google_smr_datacenters/
[14] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33aSTjlXb8tPMrSxFD5RTKNgAAAEA&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[15] https://whitepapers.theregister.com/
Decisions, decisions
Pen-y-gors
You come up with a completely new design for something and you have a choice. Utilise Helium as a coolant, an expensive gas that is getting rarer by the day, or salt, which is cheap as chips (and good on chips) and seriously available. What to do, eh?
Fuel Shortage
thames
The problem that both X-Energy and Kairos have is where to get their very special fuel enriched to higher levels than normal commercial fuel. Currently the only commercial supplier is in Russia, which is problematic.
American and European suppliers are reluctant to build plants to supply this as there aren't currently any customers for it. It's a chicken and egg problem.
And of course from a customer perspective there is the issue of vendor lock-in with proprietary fuel designs.
Reactors using normal commercial fuel (low enriched or natural unenriched uranium) don't have this problem.
Only 144 reactors?
The 2,000 lawsuits over every aspect of them will be so easy to get past then. Good thing they're small.
/sarc
Now I wonder if the real reason for SMR's is so they can be built faster than lawsuits can be funded and filed. Most distribution architecture has been designed to utilize large generators at a few discrete locations rather than small ones all over the place.