American Nuclear Society

✴️ Announcing the 2026 ANS Annual Conference theme: Net Out and Power Up! 👨‍🔬 Inspired by the revolutionary ideas behind nuclear fission and fusion, this year's conference will feature the minds powering nuclear's net breakthroughs. Through plenaries, executive sessions, hands-on workshops, and more, the 2026 ANS Annual Conference will elevate and inspire new ideas on how commercial advanced nuclear systems to can deliver real value. 🏔️ Join us in Denver, May 31–June 3: ans.org/meetings/ac202…

Just how "safe" are used nuclear fuel transportation casks?

This is a game-changer for commercial microreactors. Congrats to all involved!

ANS CEO Craig Piercy visited @KairosPower's Hermes demonstration site at Clinch River in Tennessee yesterday: "Watching advanced reactor construction move from paper to poured concrete is exactly the progress our nuclear sector has been working toward. They're doing it right!"

5 days. 32 hours. 5 instructors. 101. Limited spots remain in this year's Nuclear 101 course taking place in conjunction with the 2026 ANS Annual Conference. This comprehensive program, led by industry experts, offers hands-on learning that covers key nuclear topics and a certificate following successful completion of the course. Don't miss out - register today: ans.org/nuclear101/

Read more: ans.org/news/2026-04-1…

The 2026 ANS election results are in! During this election cycle, members voted for the newest vice president/president-elect and five board of director positions (four U.S., one non-U.S.) The next vice president/president-elect will be Rebecca Steinman, senior manager of licensing at @ConstellationEG. Steinman will succeed current ANS vice president/president-elect Mark Peters, who will assume the office of president following the upcoming ANS Annual Conference in early June. The new members of the board of directors include: ▪️Kirsten Laurin-Kovitz, associate laboratory director of nuclear technologies and national security at @argonne ▪️Leah Parks, siting manager for @KairosPower and formerly of @NRCgov ▪️Sandra Sloan, senior advisor of product development at @BWXT ▪️Paul Wilson, Department Chair and Professor of Nuclear Engineering & Engineering Physics at @UWMadisonNEEP ▪️Catherine Prat (non-U.S. board member), lead engineer at @WECNuclear working in Bulgaria

It’s go-time for the $800M we’re pumping into Byron and Braidwood Clean Energy Centers to add a total of ~158 MW of reliable, emissions-free nuclear power to the grid. Our Generation leaders checked in from Byron on the work underway.

As part of our plans for a fleet of AP1000® power plants in the United States, Westinghouse has submitted a Design Control Document (DCD) to @NRCgov that establishes Plant Vogtle's Unit 4 reactor as the standard AP1000 reference plant for future reactors. A DCD defines the technical aspects of a standard reactor design to ensure it meets all regulatory and safety requirements. Learn more about this important step toward an AP1000 reactor fleet in the U.S.: info.westinghousenuclear.com/news/westingho… Pictured: Plant Vogtle Unit 4 in the foreground, with Unit 3 in the background. Both AP1000 reactors in the state of Georgia are setting performance records since entering commercial operation. (Photo courtesy of Georgia Power)

The power response of a reactor during an event is determined by the sum of all the reactivity feedback effects, not just one. Fast reactors like Natrium are designed so that the overall temperature and power coefficients are negative, meaning the reactor power tends to go down if the temperature increases. Moreover, liquid sodium is a very efficient heat transfer medium and the fluid is hundreds of degrees below the sodium boiling temperature at low pressure operating conditions, so a rapid boiling scenario like Chernobyl could not occur.

@ANS_org @Unplugnukes @lyndalovon @iaeaorg @NRCgov Actually, no. I'm very familiar with the design, as well as the functional containment review. The Natrium has a positive coolant void coefficient, just like Chernobyl. In certain accident sequences, there will be a rapid power excursion and a likely failure of confinement.

The American Nuclear Society supports the International Atomic Energy Agency's (@iaeaorg) calls for maximum military restraint around nuclear power plants and civilian research reactors, and for full adherence by all combatants to the IAEA's seven pillars for nuclear safety and security during armed conflict.

@NucSafetyUCS @Unplugnukes @lyndalovon @iaeaorg Regarding the NSC, the IAEA "found that there was no permanent damage to its load-bearing structures or monitoring systems." The agency is planning restoration after temporary repairs— not replacement. Received damage, yes. Ruined, no. iaea.org/newscenter/pre…

@ANS_org @Unplugnukes @lyndalovon @iaeaorg And the single drone strike on the New Safe Confinement depressurized the entire volume and hence ruined the structure, so I wouldn't downplay the destructive effect of the attack.

Ed, Natrium does have containment — NRC-accepted functional containment with multiple barriers. Not a traditional dome, but that's viable because the physics are fundamentally different: it runs at atmospheric pressure, and as temperature rises, reactivity falls automatically. Natrium design self-stabilizes. That's the opposite of Chernobyl's failure mode, where the 1986 RBMK became more reactive as it heated up at low power.

@ANS_org @Unplugnukes @lyndalovon @iaeaorg Well, now you're being misleading. You know that @NRCgov approved a construction permit for the Natrium, which will not have a physical containment, setting a precedent for future US reactors. If an applicant came to the NRC with an RBMK design today it likely would be approved.

So many errors in one tweet. Let's set the record straight: 1) Chernobyl Unit 4 had NO containment dome in 1986 — a deliberate Soviet cost-cutting shortcut. Western-style/modernized reactors do have concrete-and-steel containment domes. 2) The Feb. 2025 drone struck the New Safe Confinement (NSC) — a steel arch slid over Unit 4's sarcophagus. The NSC is NOT a reactor containment dome. And the drone only breached the outer cladding. The sarcophagus beneath was untouched. IAEA confirmed: no radiation increase as a result of the drone.

@ANS_org @lyndalovon @NucSafetyUCS @iaeaorg It only took a single Russian drone to blast a hole in Chernobyl’s “thick concrete containment!” Stop enabling nuclear disaster, call for cold shutdown, NOW!

I need to lock in @ANS_org 👀

Nuclear energy is among the safest and cleanest of energy technologies. Nuclear power plants are robust, hardened pieces of critical infrastructure built to withstand natural and man-made hazards. Thick, steel-reinforced concrete containment buildings protect reactor cores and are designed to keep radioactive materials isolated from the environment. Still, nuclear plants, like all other industrial civilian infrastructure, were not designed with war in mind. For the data, see Oxford University's and Global Change Data Lab's @OurWorldInData — the numbers speak for themselves: ourworldindata.org/safest-sources…

So much for nuclear power being safe.

Nuclear energy is among the safest and cleanest of energy technologies. Nuclear power plants are robust, hardened pieces of critical infrastructure built to withstand natural and man-made hazards. Thick, steel-reinforced concrete containment buildings protect reactor cores and are designed to keep radioactive materials isolated from the environment. Still, nuclear plants, like all other industrial civilian infrastructure, were not designed with war in mind. For the data, see Oxford University's and Global Change Data Lab's @OurWorldInData — the numbers speak for themselves: ourworldindata.org/safest-sources…

@ANS_org @NucSafetyUCS @iaeaorg Oh, I thought nuclear power was safe? Golly. You’re changing your tune now.

Imagine if a documentary crew had been embedded with Oppenheimer, Fermi, and other scientists in the 1940s, watching history unfold in real time. Capturing the awe, the hope, the breakthroughs, and the world-changing decisions as they happened. We can’t travel back to the first Atomic Age. But we can be there for the second one. Right now, a new nuclear renaissance is quietly coming into existence. The technology, the visionaries, the political will, and the existential stakes are all colliding at once… and almost no one is telling the full story. Until now. I’m beyond thrilled to announce that I’m co-creating a multi-year epic documentary series called The Last Renaissance, together with award-winning director @TysonCulver. We’re gaining unprecedented, real-time access to the brilliant founders, new reactor designs, daring entrepreneurs, and the key players inside government who are rewriting humanity’s energy future. This is a civilization-level turning point that could reshape climate, geopolitics, prosperity, and even space exploration for the next century. This is the kind of story that only comes around once in a generation. I feel profoundly lucky to be in the room where it’s happening. And if you feel the call, if you’re as electrified by this moment as we are, we want you with us. Whether you’re an investor, a scientist, an engineer, a policymaker, or simply someone who believes this renaissance deserves to be witnessed by the world… Join us. The Atomic Age 2.0 is already underway. Let’s make sure the world doesn’t miss it.

NASA is advancing nuclear power and propulsion in space to accomplish President Trump’s national space objectives. With SR-1 Freedom, launching in 2028, we will demonstrate nuclear electric propulsion and deliver SkyFall helicopters to Mars. In collaboration with @Energy, these capabilities are key to future missions to Mars and beyond. A new chapter of deep space exploration begins. 🚀

For full statement: ans.org/news/2026-04-0…

American Nuclear Society joins @iaeaorg in calling for protection of nuclear power plants in armed conflicts: “The American Nuclear Society (ANS) supports the International Atomic Energy Agency's (IAEA) calls for maximum military restraint around nuclear power plants and civilian research reactors, and for full adherence by all combatants to the IAEA's seven pillars for nuclear safety and security during armed conflict.”