Retired nuclear engineer. Climate action and nuclear power advocate. Supporter of tech-neutral climate policies.

Tracy, CA
Joined October 2020
James Hopf retweeted
Within the next few weeks, the U.S. Nuclear Regulatory Commission (NRC) expects to issue the Construction Permit for TVA's first BWRX-300 at the Clinch River site. The Clinch River site has an Early Site Permit that allows multiple units; this decision will cover just one unit.
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James Hopf retweeted
Bermuda is a prosperous island with an average electricity consumption of about 60 MW with a peak generating capacity of about 130 MW. Virtually all of that capacity is supplied by large diesel generators burning fuel with a regulated cost of $142/MWh It is an intriguing target market for SMR vendors. Bermuda's Royal Gazette newspaper published an opinion piece titled "A nuclear option for Bermuda’s energy future" providing Duncan Card's thoughts on the matter.
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James Hopf retweeted
A newly signed nuclear cooperation agreement enables numerous mutual benefits for the United States and Saudi Arabia. 1. Lets Saudi Arabia move more rapidly towards a clean energy economy and away from one that is almost entirely dependent on oil and gas. 2. Strengthens long lasting ties between two traditional allies 3. Unlocks many billions of dollars worth of projects for both American and Saudi companies 4. Increases potential for abundant electricity and heat for a growing population and diversifying economy. A significant opportunity is increased fresh water production. 5. Diversifies global supply of commercial nuclear fuel with potential for both raw material and finished products. Note: Saudi Arabia's actinide resources are often described as "unproven." Given Saudi Arabia's reticence about sharing details about its mineral wealth, a better term would be "undisclosed." The peninsula's landscape looks like one that would host areas with useful concentrations of #uranium. Decades worth of widely distributed well logs are surely available internally.
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Colombia Just Passed a Historic Nuclear Law! Check out this video made by our Atomic Ambassadors!
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It’s a scandal that New Yorkers let Andrew Cuomo and RFK Jr shut down Indian Point nuclear plant. It would make up this entire deficiency!
NYISO’s base case shows NYC heading toward a power deficiency by 2031! CHPE, Empire Wind, + Propel NY combined don’t close the gap. If you care about climate, you have to care about this! Clean energy advocacy has to take supply adequacy at least as seriously as target-setting.
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Scoop: Amazon-backed reactor startup X-energy just won NRC approval of the environmental review for its debut plant in Texas. It's historic, from an environmental permitting perspective. This is the first time the agency has given a project the green light after a months-long environmental assessment rather than years-long environmental impact statement. I'll put a link to my @CanaryMediaInc story in the comments.
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James Hopf retweeted
Who knew that Japan had a sizable inventory of HALEU available? Obviously, there were people who knew about the material in the Department of Energy (DOE) complex and in Japan. Yesterday, the DOE announced that the material had been transferred to the US. "U.S. Secures Largest-Ever HALEU Shipment to Power American Nuclear Industry" This is what problem solvers do.
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Turbines for nuclear are easier to buy than turbines for gas plants. We bought our first one a few months ago, and it's arriving later this year. Nuclear plants use *steam* turbines, which operate at lower temperatures than combusting gas. Turbine blades are nowhere near as big a bottleneck for nuclear & steam. A modern gas turbine inlet runs at 1,500 C. Light water reactor steam turbine inlets run at 285 C. Aalo's steam turbines will run closer to 400 C. At 285 - 400 C, you can use more common metal alloys and manufacturing techniques. No single crystals, no vacuum furnaces, no 90-week grow times. 3 companies on Earth can cast a hot-section gas blade, while over 10 companies can forge a steam turbine rotor, for the smaller turbines used by smaller nuclear reactors like Aalo-1. Steam turbines (esp <= 50 MWe) are a more mature commodity. There's more to this story though, and a fascinating history... going to post a follow up soon.
You cannot buy a new gas turbine until 2030. Order books at GE, Siemens, and Mitsubishi stretch to 2029. Turbine prices have nearly tripled since 2019. Every AI data center needs power and every gas plant needs a turbine. And every turbine has one part that bottlenecks the entire industry: The blade. It has to survive in gas 500°C above the melting point of the metal it's made from and spin at up to 20,000 RPM under 10,000 g of centrifugal force. Each blade is grown as a single crystal of nickel superalloy, pulled through a vacuum furnace at 3 mm per minute. A set of blades costs $600,000 and takes 90 weeks to grow. The same metallurgy powers modern jet engines. Only 3 companies on Earth can build one. China spent $42 billion trying to catch up. They bought a Russian fighter engine, took it apart, and copied every part. Their copy ran 30 hours between overhauls versus 400 for the original. Modern Western engines run 4,000. You can reverse engineer the shape of a turbine blade. You cannot reverse engineer 60 years of metallurgy.
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Belgium Shut Down Nuclear Reactors… Now It Wants Them Back Read the full report from @RadiantEnergyG here: radiantenergygroup.com/repor…
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An excellent guide for what made the ABWR a success. It was built on continuity of experience and a supply chain that was mature. In the USA - WE ARE STARTING FROM SCRATCH - and that MUST MUST MUST be recognized. You can measure how actually serious the plans are for a nuclear build out in the USA is when someone is announces a new foundry with the forge required for reactor pressure vessel fabrication. The most important important part of a reactor and the ability to manufacture that in the USA DOES NOT EXIST - and there are currently NO announced plans to restore that capacity. This is why my proposal for a vertically integrated "Nuclear Power Company" is the ONLY way this is going to happen. That is the only way we can get to the point of having ABWR builds in the USA. The ABWR in south texas was canceled after Toshiba told them the cost was going up by 4 billion dollars - because the supply chain and infrastructure for building it didn't and still doesn't exist in the USA.
Whatever happened to the World’s fastest constructed reactor? The Advanced Boiling Water Reactor (ABWR) was built in just 38 months of nuclear construction but after its lightning deployment in Japan it failed to lift off internationally. What the heck happened. A mega 🧵 The U.S. Department of Energy has begun exploring alternatives to America’s flagship reactor, the AP1000. The proximate cause is not dissatisfaction with the AP1000’s design but rather frustration with Westinghouse’s slow pace. As a result GE Hitachi’s 1350MW Advanced Boiling Water Reactor (ABWR) is getting a second look.
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James Hopf retweeted
Adam Stein@Dr_A_Stein17 Jul 2025
🏗️Trilled to finally introduce ACTION, to accelerate nuclear energy deployment. It is a milestone-based program to address the root causes of project risk for advanced nuclear energy projects.
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New Jersey Lifts Nuclear Moratorium — Senator @AndrewZwicker Explains What’s Next!
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James Hopf retweeted
NRC is "sunsetting" the Aircraft Impact Assessment rule - 10 CFR 50.150. That rule has always been unnecessary and 100% more costly than its absence would have been. Even the NRC said so in the Federal Register at the time that the rule was initially promulgated. A word search on Federal Register / Vol. 74, No. 112 / Friday, June 12, 2009 / Rules and Regulations "Consideration of Aircraft Impacts for New Nuclear Power Reactors" shows the phrase "not necessary for adequate protection" appearing at least 4 times.
🚨 The Aircraft Impact Assessment will be sunset!!!!! The NRC states they have addressed the previous comments against sunsetting the rule and have determined it's appropriate to end the enforcement of the regulation!!! Goodbye AIA 🤘 link below
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Germans could just turn their nuclear plants back on… but instead they’re building vertically, floating solar panels —while still burning coal.
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Italien prüft fast 40 Jahre nach dem Ausstieg ein Comeback der Kernenergie. Die Meloni-Regierung lässt Experten konsultieren & diskutiert konkrete Schritte, um die nach Tschernobyl diskreditierte Technologie wieder einzuführen. Ein Grund sind Italiens hohe Strompreise. Realistisch erscheinen neue AKWs aber erst nach 2035 bloomberg.com/news/articles/…
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James Hopf retweeted
Now that DOE Environmental Management has announced the the FMEF at Hanford will be returning to service, perhaps a similar decision can be made about the nearby FFTF? FMEF – Fuels and Materials Examination Facility FFTF – Fast Flux Test Facility Both of these large, capable and underused facilities were built as part of the breeder reactor program. Both were put out to pasture by the Clinton Administration's ill-advised decision to halt all advanced reactor research. Neither was destroyed. Instead they were put into long term, low cost surveillance and maintenance. Both can provide a way to accelerate nuclear energy industry progress. Restoration is a far better option than dismantling. @ENERGY @GovNuclear @EMcleanup
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James Hopf retweeted
Triso fuel costs have vast room for improvement. Those tiny coat particles will be manufactured by the billions, allowing economies of truly mass manufacturing to come to nuclear fuel production. @standardnuclear is making the fuel now, with plans to add additional lines to its licensed and proven initial, modular production line. #HALEU #Uranium
One year ago: @StandardNuclear launched. Today: We started first-of-a-kind HALEU processing operations. Our team is now manufacturing fuel for @RadiantNuclear's microreactor. This is what rebuilding American nuclear fuel capability looks like. 🇺🇸
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SOUTH KOREA CLEARS THE WAY FOR NEW NUCLEAR REACTOR TO START IN 2026 🇰🇷☢️ 👍 Sauel No. 3 reactor was approved to begin operations. The plant has been under construction since 2016 ⚡ The reactor is poised to begin commercial operations next year after a six-month trial run
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James Hopf retweeted
Adam Stein@Dr_A_Stein5 Dec 2025
Congratulations to Ho Nieh on being sworn is as a Commissioner of the @NRCgov!
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We need to get serious about actual impacts (way less than literally EVERY other option), and stop the politicking, leveraging, and attempted land grabbing. I expect better from public agencies in California (somewhat naively since I’ve seen firsthand how many handle nuclear).
“Currently, the California Coastal Commission poses the most serious impediment to the state’s efforts to extend operations at Diablo Canyon—largely over the issue of fish larvae.” @wang_seaver on the Coastal Commission’s baseless regulatory caprice:
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