Much fanfare is being made over China’s Thorium-fueled TMSR-LF1 reactor, a 2-megawatt molten salt testbed buried in the Gobi Desert. Western media hails it as a sign of China’s nuclear innovation and a shot across the bow in the clean energy arms race. The reality? While impressive, this “breakthrough” is at best a demonstration of persistence—not leadership. Because if you’re looking for a true proof-of-concept for compact, modular nuclear reactors that actually work in extreme conditions and have done so for decades, you don’t need to dig through desert sand—you just need to dive a little deeper.
Let’s state this plainly: the U.S. has already mastered small modular reactors (SMRs)—not in theory, but in practice. The American nuclear navy has been operating SMRs reliably since the USS Nautilus (SSN-571) first went to sea in 1955. That’s nearly 70 years of operational data— including in some of the harshest environments on Earth, under the crushing pressure of the deep ocean, far from any repair depot, under combat-ready protocols. The Chinese are building a test reactor. We’ve been living with working versions since the Eisenhower administration.
The Stats:
- The U.S. Navy operates over 80 nuclear-powered submarines and aircraft carriers.
- Each submarine runs on a pressurized water reactor (PWR) delivering between 150-200 megawatts thermal (MWth), with newer Virginia-class reactors estimated at 210 MWth, converting to roughly 40-50 MWe.
- These reactors are compact, modular, refuelable only once every 30+ years, and built to military-grade redundancy.
- Submarine reactors are often smaller in volume than land-based SMRs currently in development—yet far more resilient, thanks to decades of battlefield-level engineering.
Let that sink in: the U.S. already mass-produces modular nuclear reactors that can power cities—if redirected. We have the supply chains, the know-how, and the deep institutional experience. The only thing we lack? Political will and regulatory sanity.
Modularity?
Each submarine reactor is a self-contained power plant, built in shipyards under tight tolerances, and installed within vessels where space is at a premium. Modularity isn’t a buzzword—it’s a necessity.
Manufacturing? Decades Ahead.
The U.S. has built hundreds of these nuclear systems, with predictable timelines, standardized protocols, and trained nuclear personnel operating them 24/7.
Safety Record? Untouchable.
Despite operating reactors in mobile military platforms, the U.S. Navy has experienced zero nuclear reactor accidents involving radiological release in nearly 8,000 reactor-years of operations. That’s more than any civilian nuclear fleet can boast.
So while China builds experimental molten salt testbeds, the U.S. is sitting on a golden goose of SMR capability, and barely anyone talks about it. Why? Because applying this military-grade technology to the civilian grid requires untangling a web of regulatory dysfunction, outdated NRC oversight models, and a media ecosystem that still thinks "nuclear" equals "danger."
We’ve already solved the hard problems—compact design, passive safety, modular build, long-life fuel. The reactors that silently patrol the oceans are the real SMRs. We just refuse to deploy them at scale on land.
China’s TMSR-LF1 is a cool science project. But the U.S. has been operating mobile SMRs in stealth mode since before man walked on the Moon. If we were serious about energy, climate, or resilience, we’d dust off the blueprints, convert naval expertise into civilian deployment, and stop acting like this is new.
We’ve already won this race—we’re just sitting on the trophy.
I love this series as I loved your end-of-year podcasts on the subject as well. Planning to do more work in this area. Perhaps its worth learning about the politics in Washington and in various important states about prospects for rolling this out sooner rather than later. Is there an event that might serve as a Sputnik moment for all of this? It seems the news this week was one for you and me, but not for the president or other politicians.
A bit of an asside, but i think direct process heat is highly over rated in the advocate community.
The challenge there is getting the heat into the target process. Most of the actual high temp processes use direct combustion within the process. Using indirect means process heat exchangers are required, and they get very, very challenging at even 600C (with all the dusts and corrosive components in process gas), and exponentially morso above that. This is especially true if you cannot tolerate leaks of primary coolant into the process.
Industrial support via electrification, and supply of enormous volumes of steam are going to be the primary methods, but they do not mandate as high temp of designs.
The other area that gets brought up is hydrogen production. Themochemcial H2 cycles are just not going to be a thing. Steam. Electolysis is fine. And while steam electolysis (in SOEC) *opperates* at ~800C, the heat input needed is only ~150C steam. The reason is that the products are also that hot, and they need to be cooled down, so they are used to pre-heat the reactants. A small amount of electrical topping is inconsequential after that.
The steam conditions at the HP turbine exhaust are right in the ballpark for the feed to a SOEC, so you still can get some power from that export steam.
Also by using LP steam its a one way export, and the H2 production can be a few km away from the reactor without integration challenges of needing a very high temp recycle stream.
Thank you once again for the interesting post Erik.
If I may add on, Alvin Weinberg actually addressed why nobody seems to "get it" in The First Nuclear Era. On pages 130-131, "Perhaps the moral to be drawn is that a technology that differs too much from an existing technology has not one hurdle to overcome--to demonstrate its feasibility--but an even greater one--to convince influential individuals and organizations who are intellectually and emotionally attached to a different technology that they should adopt the new path. This, the molten-salt system could not do...."
The comment below is a perfect testament to Weinberg's insights.
Much fanfare is being made over China’s Thorium-fueled TMSR-LF1 reactor, a 2-megawatt molten salt testbed buried in the Gobi Desert. Western media hails it as a sign of China’s nuclear innovation and a shot across the bow in the clean energy arms race. The reality? While impressive, this “breakthrough” is at best a demonstration of persistence—not leadership. Because if you’re looking for a true proof-of-concept for compact, modular nuclear reactors that actually work in extreme conditions and have done so for decades, you don’t need to dig through desert sand—you just need to dive a little deeper.
Let’s state this plainly: the U.S. has already mastered small modular reactors (SMRs)—not in theory, but in practice. The American nuclear navy has been operating SMRs reliably since the USS Nautilus (SSN-571) first went to sea in 1955. That’s nearly 70 years of operational data— including in some of the harshest environments on Earth, under the crushing pressure of the deep ocean, far from any repair depot, under combat-ready protocols. The Chinese are building a test reactor. We’ve been living with working versions since the Eisenhower administration.
The Stats:
- The U.S. Navy operates over 80 nuclear-powered submarines and aircraft carriers.
- Each submarine runs on a pressurized water reactor (PWR) delivering between 150-200 megawatts thermal (MWth), with newer Virginia-class reactors estimated at 210 MWth, converting to roughly 40-50 MWe.
- These reactors are compact, modular, refuelable only once every 30+ years, and built to military-grade redundancy.
- Submarine reactors are often smaller in volume than land-based SMRs currently in development—yet far more resilient, thanks to decades of battlefield-level engineering.
Let that sink in: the U.S. already mass-produces modular nuclear reactors that can power cities—if redirected. We have the supply chains, the know-how, and the deep institutional experience. The only thing we lack? Political will and regulatory sanity.
Modularity?
Each submarine reactor is a self-contained power plant, built in shipyards under tight tolerances, and installed within vessels where space is at a premium. Modularity isn’t a buzzword—it’s a necessity.
Manufacturing? Decades Ahead.
The U.S. has built hundreds of these nuclear systems, with predictable timelines, standardized protocols, and trained nuclear personnel operating them 24/7.
Safety Record? Untouchable.
Despite operating reactors in mobile military platforms, the U.S. Navy has experienced zero nuclear reactor accidents involving radiological release in nearly 8,000 reactor-years of operations. That’s more than any civilian nuclear fleet can boast.
So while China builds experimental molten salt testbeds, the U.S. is sitting on a golden goose of SMR capability, and barely anyone talks about it. Why? Because applying this military-grade technology to the civilian grid requires untangling a web of regulatory dysfunction, outdated NRC oversight models, and a media ecosystem that still thinks "nuclear" equals "danger."
We’ve already solved the hard problems—compact design, passive safety, modular build, long-life fuel. The reactors that silently patrol the oceans are the real SMRs. We just refuse to deploy them at scale on land.
China’s TMSR-LF1 is a cool science project. But the U.S. has been operating mobile SMRs in stealth mode since before man walked on the Moon. If we were serious about energy, climate, or resilience, we’d dust off the blueprints, convert naval expertise into civilian deployment, and stop acting like this is new.
We’ve already won this race—we’re just sitting on the trophy.
I love this series as I loved your end-of-year podcasts on the subject as well. Planning to do more work in this area. Perhaps its worth learning about the politics in Washington and in various important states about prospects for rolling this out sooner rather than later. Is there an event that might serve as a Sputnik moment for all of this? It seems the news this week was one for you and me, but not for the president or other politicians.
Hello Erik,
I hope this communique finds you in a moment of stillness. Have huge respect for your work.
We’ve just opened the first door of something we’ve been quietly crafting for years—
A work not meant for markets, but for reflection and memory.
Not designed to perform, but to endure.
It’s called The Silent Treasury.
A place where judgment is kept like firewood: dry, sacred, and meant for long winters.
Where trust, patience, and self-stewardship are treated as capital—more rare, perhaps, than liquidity itself.
This first piece speaks to a quiet truth we’ve long sat with:
Why many modern PE, VC, Hedge, Alt funds, SPAC, and rollups fracture before they truly root.
And what it means to build something meant to be left, not merely exited.
It’s not short. Or viral. But it’s built to last.
And if it speaks to something you’ve always known but rarely seen expressed,
then perhaps this work belongs in your world.
The publication link is enclosed, should you wish to open it.
https://helloin.substack.com/p/built-to-be-left?r=5i8pez
Warmly,
The Silent Treasury
A vault where wisdom echoes in stillness, and eternity breathes.
A bit of an asside, but i think direct process heat is highly over rated in the advocate community.
The challenge there is getting the heat into the target process. Most of the actual high temp processes use direct combustion within the process. Using indirect means process heat exchangers are required, and they get very, very challenging at even 600C (with all the dusts and corrosive components in process gas), and exponentially morso above that. This is especially true if you cannot tolerate leaks of primary coolant into the process.
Industrial support via electrification, and supply of enormous volumes of steam are going to be the primary methods, but they do not mandate as high temp of designs.
The other area that gets brought up is hydrogen production. Themochemcial H2 cycles are just not going to be a thing. Steam. Electolysis is fine. And while steam electolysis (in SOEC) *opperates* at ~800C, the heat input needed is only ~150C steam. The reason is that the products are also that hot, and they need to be cooled down, so they are used to pre-heat the reactants. A small amount of electrical topping is inconsequential after that.
The steam conditions at the HP turbine exhaust are right in the ballpark for the feed to a SOEC, so you still can get some power from that export steam.
Also by using LP steam its a one way export, and the H2 production can be a few km away from the reactor without integration challenges of needing a very high temp recycle stream.
Thank you once again for the interesting post Erik.
If I may add on, Alvin Weinberg actually addressed why nobody seems to "get it" in The First Nuclear Era. On pages 130-131, "Perhaps the moral to be drawn is that a technology that differs too much from an existing technology has not one hurdle to overcome--to demonstrate its feasibility--but an even greater one--to convince influential individuals and organizations who are intellectually and emotionally attached to a different technology that they should adopt the new path. This, the molten-salt system could not do...."
The comment below is a perfect testament to Weinberg's insights.
Daunting...It's akin to a great company like Xerox resting on its laurels until it evaporated....
thanks for another great, informative piece.
i love macrovoices, too.