It's a true miracle of nature that water is both a good neutron moderator and reactor coolant. Its ability to moderate and cool at the same time is quite underappreciated in today's pro-nuclear circles.

The first Boiling Water Reactor experiments (BORAX) www.youtube.com/watch?v=oLlK...

Pretty neat model of a PWR from the 1965 Boy Scouts Atomic Energy merit badge book. Honestly, building this would help kids understand quite a bit about a reactor.

Looking into the core of BORAX-5, which pushed the limits of what a BWR could do: nuclear superheat and natural circulation. The superheat region is in the center. BWRs today are not so bold as to superheat steam. Have materials improved enough to try again? Probably!

We need Nuclear Reactor Consumer Labels! whatisnuclear.com/news/2025-08...

Getting these 45 historical nuclear films from 1955-83 dug up and digitized has been one of the coolest and most rewarding things I've done with What is Nuclear. Thanks to you all for your interest and support in this project! There are only ~100 left to get. whatisnuclear.com/museum/

For all you Anki users out there (free spaced repetition learning app), I made a deck for memorizing the US Nuclear Power Plants. Planning to expand it more later but it's starting out with just the operational commercial units. ENJOY! github.com/whatisnuclea...

Observation: the actions that get more investors to buy into your nuclear company are currently the opposite of those needed to develop an economical, operable, maintainable, and safe nuclear plant. Anyone have ideas about how to bring these back into alignment?

CNA in Singapore produced a nuclear power documentary called "The Nuclear Option" that you can watch online. They visited many key places and talked to lots of people. It came together super well! www.youtube.com/playlist?lis...

Beryllium triflute that fit between the pins in the PPA. Who's working on beryllium triflutes today?!

Here's Preliminary Pile Assembly-19, where rotating control drums were first mocked up in a critical facility around 1951. Note the six smaller hexagon outlines on each corner of the central hex, each of which represents a control drum.

We debate this endlessly within the pro-nuclear world, but I really don't think it's super complicated. There's plenty of room to promote either without throwing the other under the bus.

New safety minute about the WTR fuel failure whatisnuclear.com/safety-minut...

Here's the Neutronics Scoping Tool, which allows you to dial in a certain core height, radius, enrichment, and power rating and see if it will go critical and how long it will run. Then, it estimates the fuel LCOE, average discharge burnup, and a whole lot more. www.youtube.com/watch?v=GQzD...

Big Rock Point in Northern Michigan was the prettiest nuclear plant. It's crazy that one little 71 MWe plant like this can make enough electricity to power a whole county in peak fudgie season.

The Rickover memo in the form of a Dunning-Kruger curve whatisnuclear.com/news/2025-06...

Natural uranium is mostly U-238, with a 4.5 billion yr half-life. A kg of it kicks out 12M alpha particles per second with 4 MeV of energy each, generating 8 microwatts of ionizing radiation. It's not super hazardous, and you can hold it in the palm of your hand with a glove.

After much effort, I'm happy to finally present the Universal Reactor Memorandum of Understanding (MOU). This MOU is hereby issued between all current and future reactor companies and all current and future power customers. Congrats to all.

I just won a chunk of graphite from the world's first man-made nuclear reactor (CP-1) in a raffle from at the #ANSAnnual conference. I've desperately wanted one of these for decades, and entered at the last minute, thanks to a serendipitous seating at the lunch table. I'm so lucky and grateful!

Statement on firing of NRC Commissioner Hanson: www.ans.org/news/2025-06...

BREAKING: Nuclear Regulatory Commissioner Chris Hanson has been fired by President Trump. The NRC is one of the most independent agencies in the Federal Government. Statement from Hanson.

Who's all coming to #ANSAnnual in Chicago?

"The reaction among all the crews was: doesn't the country realize what they're losing here?" "This was a neat machine, there wasn't anything wrong with it, but we had to shut it down" Have you ever teared up watching a reactor film? Well get ready to! www.youtube.com/watch?v=Xf7O...

Here are 4 more digitized Clinch River Breeder Reactor films, all thanks to Aalo Atomics. This batch is a bit more on the technical/engineering side rather than the public interest/entertainment side, in that they're video recordings of experiments (thread)

I may have peaked as a nuclear engineering intern at the Idaho National Lab

Slightly less exciting than other vids, but here's a recorded NRC ASLB meeting discussing the Clinch River Breeder in 1982. I did an AI transcription in case you'd rather skim the text. whatisnuclear.com/crbrp-aslb-h...

"The Next Step – Progress Report: The Clinch River Breeder Reactor Plant Project" (1980) tells the Clinch River Breeder story and shows more components, the training control room, and the amazing physical model (not CAD) built at Burns and Roe. Thanks to Aalo Atomics! www.youtube.com/watch?v=EJ-G...

A little demo showing how to use the What is Nuclear fuel cost calculator www.youtube.com/watch?v=2Yop... calculator is here: whatisnuclear.com/enrichment.h...

Presenting "Endless Energy with Dr. Edward Teller (1981)" 📽️🍿, a newly digitized film! It tells the story of nuclear, safety, regulation, breeders, fusion, thorium, fission-fusion hybrids, and even the OG traveling wave idea. Thanks to Aalo Atomics! www.youtube.com/watch?v=eTRz...

"The Story of The Atomic Airplane": 13 hours of first-hand presentations and interviews from the team that did the nuclear-powered aircraft project in the 1950s, now digitized and online thanks to Dr. Jake Hecla! whatisnuclear.com/the-story-of...

Here, I made a handy radiation dose conversion chart for ya

Everyone says nuclear power is overregulated. With the big nuclear EOs looming, I spent a few weeks talking to people in the nuclear industry to find out which reforms they thought would be most helpful, and which they were nervous about. Here are the top 12. whatisnuclear.com/news/2025-05...

And here's a bonus 3-minute update showing more of the Peach Bottom HTGR prototype reactor under construction. You can see the key components: the pressure vessel, control rod drive extensions, steam drums, steam generators, hot valves, helium compressors, and more. www.youtube.com/watch?v=vDjX...

An amazing film depicting General Atomic's development of the Peach Bottom High Temperature Gas-cooled Reactor (HTGR) in Pennsylvania. 53 private utilities banded together to fund the prototype reactor. www.youtube.com/watch?v=dSXV...

If you're ANYWHERE NEAR Baltimore, don't miss this chance to hop aboard the Nuclear Ship Savannah for National Maritime Day 2025. Sunday May 18, 10am–3pm 4601 Newgate Ave, Baltimore, MD 21224, USA www.ns-savannah.com/event-detail...

Hey TRISO modelers, when you build a neutronics input with TRISO fuel, what are your favorite ways to set a given packing fraction without cutting off particles on the edge of your pebble or compact? Does everyone just write a packing script?

Crazy story: in the early 1990s, the USA purchased 6 TOPAZ-II space nuclear reactors from the USSR/Russia and flew them to New Mexico for testing. These reactors had thermionic cells directly surrounding each of their 37 fuel pins! whatisnuclear.com/news/2025-05...

This is one of the most important messages in advanced nuclear right now. www.ans.org/news/2025-05...

Here's the unfinished/abandoned Juragua Nuclear Power Plant in Cienfuegos, Cuba. They planned to build 12 VVER-440s with the help of the USSR but pulled the plug on the project in 1997. en.wikipedia.org/wiki/Juragua...

Intermediate heat exchanger comparison for some sodium-cooled reactors

Read this book.

The first US involvement in peaceful nuclear fusion research was called "Project Sherwood" and happened under much secrecy between 1951–1957. In 1958, it was presented publicly through films like this one. Just digitized, thanks to Adam Rizika for making this happen. www.youtube.com/watch?v=t2W6...

Beautiful animated breeder reactor film here from the late 1970s, with a to-the-point description of breeders and then a detailed depiction of the major systems in Superphénix, the largest sodium-cooled reactor ever built. www.youtube.com/watch?v=RSVH...

Lots of major equipment was fabricated for the Clinch River Breeder. Here's testing of the reactor closure head. The rotating plugs allow fuel handling without opening up the reactor. Inset rotating plugs allow you to reach all core positions. Thanks to @AaloAtomics for making this scan possible.

Here are the proposed changes in Dept of Energy budget from the White House's budget plan released yesterday:

LANL is planning to vent some radioactive tritium. They did a worst-case analysis and found that the highest dose any one person could get is 20 mrem, which is pretty low, roughly the same as taking 5 round-trip flights. This is ~1/15th the average yearly natural background dose.

New film digitized: "Target for Antares (1978)" This one covers laser fusion and shows the intricate process they use for building Deuterium-Tritium fusion fuel targets. This was in support of the Antares laser fusion facility at Los Alamos. www.youtube.com/watch?v=eoHr...

Views of the massive 100 ft-deep limestone excavation for the Clinch River Breeder Reactor Plant near Oak Ridge, filmed on September 10, 1983. The embattled project was cancelled soon after, and the hole was filled back in. 😔

This is so so incredibly funny

Hey I'm in wired!