Site isn't working now, but their GitHub is here [1]. My understanding on this is that Transatomic started as two young MIT students/grads who did some calcs on a molten salt reactor, found that they could run on high-level nuclear waste in a thermal-neutron spectrum, got really excited, and started a company. They did TED talks and everything [2] and really became this awesome story about advanced nuclear, nuclear startups, private investment in nuclear doing exciting new things, and so on. They were heavily featured in a documentary about advanced nuclear [3] that you can get on Amazon, where we all got a look in their doors.

Then the trouble started. They (smartly!) asked MIT to do a design review and a few questions came up on their key claims. Turns out, there were some calculation or assumption mistakes that showed that it couldn't just run directly on nuclear waste (you traditionally need fast neutrons and/or aggressive reprocessing to do this, even in molten fuel) [4]. They adjusted their copy and moved forward with an adjusted design and new calcs. Eventually they decided to close up shop and open source their design effort as a soft closure.

It's highly regular for advanced nuclear efforts to adjust their design and strategy as they move forward. In fact, I'd go so far to say it happens in 100% of efforts. The only thing Transatomic did that might be a lesson learned is that they got really hyped up early on in their effort, before they shook it down with engineering reviews and whatnot.

As far as I can tell, no one is curating progress or roadmaps in the open source effort. I LOVE the idea of open-source reactor design. It gets around huge institutional barriers clogging up opportunities for collaboration and alignment in the nuclear space. Nuclear is traditionally very secretive, and all these startups promising the world in 2024 without collaboration is basically a doomed effort. The industry must team up, find overlapping tech development efforts and facilities, and work together to build a market. Once they build the market, they can worry about competing in it. Open source can also transcend traditional funding cycles, like when national labs work on a reactor for 2-4 years, make tons of exciting progress, and then drop it. If it's open, universities, international institutions, companies, etc. can all coordinate on it.

Doing open source reactor design would require a lean and highly-dedicated non-profit or foundation or something with a handful of nuclear design pros in it to do the coordination. These projects don't run themselves. It would also need lots of legal resources to navigate export control space. Everything Adm. Rickover said in 1953 about academic vs. practical reactors is incredibly accurate to this day [5], and using open-source philosophy to face these facts brutally may be essential for progress in nuclear.

If anyone has ideas on how to fund that kind of thing, let me know.

[1] https://github.com/transatomic/reactor/

[2] https://www.youtube.com/watch?v=AlRhcHNJed0

[3] https://www.newfiremovie.com/

[4] https://www.technologyreview.com/s/603731/nuclear-energy-sta...

[5] https://en.wikiquote.org/wiki/Hyman_G._Rickover#Paper_Reacto...