That dude sure hated Reagan!

Well, maybe not anymore.  

Natural Reactor in Africa

I think I saw another thread on nuclear waste.  This might be interesting reading for those who are curious.

That's what I had in mind when I asked the question. Allegedly, there are more

They had water as moderators. Best they can tell the only time there was "reacting" was when those natural formations were full of water. 1.5 billion years ago the proportion of U235 was higher as well.

Hot rocks and primary water, HH2o?
Possibly ask the skipjack dive team.

This is a pretty neat look at how the sausage is made.



Interesting about how long 'hot' core material needed to sit somewhere before being handled.

Since we were talking about fast reactors, read something interesting recently but don't have a link handy.

The only time the Little Boy was ever detonated was in combat, there was never a test firing of that design. There were certain aspects of weapon effects, radiation doses and the like that were never able to be answered definitively as a result. In like 1981, somewhere at Los Alamos they found some leftover Little Boy components... they fabricated some downsized active material elements and operated the Little Boy target assembly as a fast reactor to test various aspects of the design in I think 1982.

Yup, they couldn't let go of the thing, and I guess (I forget now) wanted to do dose reconstruction. Maybe there was a classified aspect to it, using the original data to scale for later systems, or something. But they spent a lot of time and money trying to pin it down. I read a report or two on it, and think I passed them to Coster-Mullen thinking they would help his 'quest'.

I can think of a reason.  Aren't gun-type bombs favored over implosion bombs for earth-penetrating warheads and wasn't there research in the 80s/90s into developing new types of smaller warheads for that target set?  Getting more experimental data with that type of weapon would seem to go along with that project.

Pu239 works better.

In my limited opinion, no.

Consider: in a GA (gun assembly) system, two or more items have to physically move a distance to be in the most favorable geometry for a reaction. In  an IA (implosion assembly) system, you are essentially simply reshaping an item or series of items via the use of conventional explosives.
You can fill the void spaces in an IA nuclear explosive package with spacers, foams, or even epoxies, making it pretty resistant to being 'dropped'.
If your GA system is impacted at 90 degrees to the direction of travel, how much beefing up do you need to do to the path to keep it aligned? If it goes head on, how do you keep the materials apart until it has penetrated to a repeatable depth? If it goes in the opposite direction, same thing but different stresses.

Example:  there was one GA artillery round that had to be carried in a certain attitude once configured for strike or there was a slight chance of a criticality / predetonation. That system used a set of devices, they were filled with a material that heated up and liquified in the flight environment, allowing a belleville spring to withdraw them from the path of the movable item. A large set of springs (yes, sounds wile e coyote, but I've been told this from numerous sources) kept that set of movable items pressed against these safety devices until they withdrew.

To assemble this fucker, they had a set of giant open end wrenches that looked like it was from a cartoon, and they took a couple of them to screw all this together.

The advantage to gun assembly is it is a very, very low bar to entering the nucweps field. You can essentially shrink a LITTLE BOY system to the size of a (relatively) small artillery shell. With a mechanically operated neutron generator, you don't have to understand the math involved of making that work at the optimum time. Adding a set of bottles of boost gas to the set of materials that don't move, in such a way they get crushed is a simple way to increase yield without complexity.

One of the reasons nucs fascinate me is that they are the prime, ultimate example of how civil technology benefits from defense research. Multi axis CNC milling came from Y12. Nobody else would spend money that fast to make that work. NiCad batteries came from Sandia to replace car batteries being used in gravity bombs. Potting of high voltage components because they failed in the high altitude environment (go from hot and dry to moist and cold all in one trip), epoxy coatings (many early weapons specified Johnson paste floor wax for the bodies, epoxy called EPON was used extensively in the assembly of pits), electrical discharge with precision (think camera flashes, but also IGBT-based welders and other devices), and metrology (the science of measuring shit). They literally had to invent more and more precise ways to measure things in the machining realm, and the timing realm, and the electrical computing realm.
On the negative side, a lot of the paperwork, hoops, and procedural stuff also came from them out there. Oops, we couldn't forsee that; we never had this before lol

I could go on for a long time about all this, I am a huge fan of the Complex and the people doing or that did all this. I don't understand it at a level like I would like, and there is way more that I don't know than I do, but it certainly isn't from asking or reading OPENNET lol

That was my impression in reading the description.


Fuel straight out of a reactor is rather hot indeed.

IIRC from the Chernobyl discussions... for fuel rods, 90% reduction in radiation in like the first minute, then another 90% reduction in the first hour. Then another 90% in a month or something like that. What that means is that the stuff right out of the reactor is smoking hot, a lot of gamma and stupendous amounts of beta. IIRC 30 to 90 days was the normal cool-off before they went to separation. I wish they hadn't torn down all the Queen Marys.

Are these The Canyons?

The canyon was the process path for spent fuel inside the plutonium separation plants, the whole building was nicknamed the "Queen Mary" in construction during the Manhattan Project.

Nah, U238 is better.

Gather enough of the right rocks together and they get hot.

Better at what? Being tank ammo?