Dean Casagrande
1.7K posts
Very excited to announce that at 12:20am on the 4th of July, Aalo achieved criticality on our first full-scale reactor. We cut it close, but we pulled it off!! Working towards this goal with such an incredible group of humans has been the most fulfilling period of my life. This moment has been three years in the making. Last year, Executive Order 14301 called for at least three new reactors to go critical before July 4th, 2026. As of late last Friday night, that goal has been surpassed! When the EO was announced, we immediately sat down to figure out what the most ambitious scope would be, while still being potentially achievable by July 4th. Some of the team proposed doing simplified designs with smaller fuel loads, or building in existing facilities. One thing was clear: We wouldn't have time to integrate a full-scale sodium heat-removal loop to bring the reactor to its full 30 MWt. So here’s where we landed: ➡️ We purchased the entire commercial-scale fuel load. This is enough fuel to operate at 30 MWt / 10 MWe for 3 years before refueling. To my knowledge, it’s the largest fuel load that’s been taken critical in the DOE pilot program, by far. ➡️ We built a full-scale reactor vessel in our factory, and loaded in our commercial graphite layout. All the dimensions, vessel thickness, and manufacturing techniques are essentially the same as we will use for the imminent commercial version. There will be a few minor tweaks for sodium flow and full-power, but nothing major. ➡️ We built an entirely new reactor facility at the Idaho National Lab. Building a building is easy. Building a new reactor facility comes with a mountain of paperwork, policies, operation and training procedures, security, instrumentation and control, and more. Zero-power criticality might seem like a small step, but I can tell you, going through the exercise of building a reactor and taking it to criticality has been extremely valuable. The learnings on regulatory, ops, manufacturing, supply chain, QA, economics, engineering, and design will accelerate our path through to the final iteration at full-power. America is blessed to have a recent Cambrian explosion of startups in nuclear, all going after different markets, technologies, and strategies. I’m excited that sodium, gas, salt, and new PWRs are all getting pushed forward once again. The best outcome for humanity is to have all these advance in parallel, as quickly as possible, while maintaining safety. Thanks again to our amazing team, DOE, INL, BEA, and everyone else who helped us get to where we are today. This could not have happened anywhere else. Happy birthday, America!! 🇺🇸🇺🇸🇺🇸 There has never been a better time for nuclear energy. The Second Atomic Age has begun, and this one will be here to stay.
@KirkHerbstreit Looks like it's time for you to start watching some soccer ⚽️
Hadron, the recently IPO'd micro reactor version of NuScale is not ok. "Hadron Energy, with its young founder, seasoned advisors, and ambitious SPAC trajectory, embodies many of the hopes currently being projected onto the American nuclear startup sector. It is perhaps the clearest example yet of how the United States is trying to innovate its way around the absence of a functioning nuclear industrial base. The notion that a startup can mobilize capital, licensing expertise, fabrication capacity, and a stable vendor ecosystem at a pace that outstrips state-directed industrial programs like the RITM-200 driven efforts to open Russia’s arctic is not supported by historical or contemporary evidence. None of this is a critique of Hadron’s sincerity or effort. Rather, it is an indictment of the “post industrial” environment in which the company operates. A young founder in the USA may believe that nuclear success is a matter of personal drive, when the real bottlenecks are the decadal loss of nuclear megaproject management skills, construction productivity, ASME N stamped fabrication, NQA 1 supply chain and heavy forging availability. The broader narrative of nuclear as a startup frontier, is therefore less a reflection of genuine opportunity than of a country that has let core industrial capabilities atrophy and now tries to outsource state capacity to private ambition." For the full essay see link in replies.
Would you rather be exposed to the radiation of 1,000 CT scans all in one go, or be hit with the same cumulative amount of radiation, but over the course of a lifetime? worksinprogress.co/issue/how-to-l… Hopefully you will not have to take that decision, but if you do, make sure it's spread out over your lifetime. There is now overwhelming evidence that low-dose-rate ionizing radiation is not that harmful. Even Chernobyl, by far the world's worst nuclear disaster, exposed millions yet has likely killed 60 or so people. A total of 200 may die early. The other bad civil nuclear disasters – Windscale, Fukushima, and Three Mile Island – likely killed nobody at all. The evidence is rolling in: ---> Many residents of Kerala are exposed to seven full-body CT scans' worth of ionizing radiation every year. But multiple studies find no effect on their health. ---> Taiwanese apartment dwellers were unwittingly exposed to up 100 CT scans per year because their apartments were made with radioactive cobalt rebar. But dwellers suffered much lower cancer rates than other age-comparable Taiwanese. ---> Between 1915 and 1950, women in factories painted radium onto watch dials to make them glow in the dark. Those licking the brushes sometimes suffered severe cancers. But non-lickers had lifetime doses equivalent to nearly 1,000 CT scans with no effect. ---> At 58 in 1945, Albert Stevens was injected with an enormous amount of plutonium, exposing him to a radiation dose equivalent to 300 CT scans every year. He lived to be 79. These and many other studies show that ionizing radiation's harms are primarily about concentrated acute doses, not low doses over a long time. Yet nuclear regulatory systems are based around the principle that any radiation exposure is totally intolerable. This leads to rules like 'ALARA' – as low as reasonably achievable – which continually ratchet up regulatory requirements, making nuclear power slow and expensive. Read my new piece with @chalmermagne for @WorksinProgMag.
