Restricted Data: The Nuclear Secrecy Blog

This is just a brief post to make sure I have announced on here formally that my new book from HarperCollins is now on sale!
The Most Awful Responsibility: Truman and the Secret Struggle for Control of the Atomic Age (HarperCollins, 2025) is a new and provocative and possibly controversial take on Harry Truman and his role in US atomic policy, from Hiroshima through the Korean...

Understanding how much fissile material — enriched uranium and separated plutonium — was produced, and at what time, by the Manhattan Project is one of those seemingly-obscure technical questions that comes with a lot of important historical implications...

I realized I haven’t updated things here for a long while, and that it would be worth consolidating a few overdue news updates.
First and foremost, if you want to read things from me on a more regular basis, you should be reading Doomsday Machines, which is another blog of mine, and is much more frequently updated that this one. While it is not exactly the same content or approach...

I happened to look at a slide deck from Sandia National Laboratories from 2007 that someone had posted on Reddit late last night (you know, as one does, instead of sleeping), and one particular slide jumped out at me:
It’s a little graphic advertising the different kinds of modeling software that are part of something called the SIERRA framework, as part of a pretty standard “overview” presentation on computer modeling at Sandia that was given at a meeting in Luxembourg...