US Army will have a portable nuclear reactor ready by 2024. Here is how it works | Hacker News Reader

US Army will have a portable nuclear reactor ready by 2024. Here is how it works

interestingengineering.com

25 pointsatombender24 comments

Portable = fits in multiple 20 feet containers. I couldn’t find how many. https://www.defense.gov/News/Releases/Release/Article/278727... calls it transportable, not portable. That seems a better word to describe that to me.

It should deliver 1 to 5 MW for at least three years of operation at full power.

I think that still counts as portable. It seems like you can unpack and spin it up in 3 days, and shut it down and pack it up for moving within 7 days. That actually seems insanely portable for what it is.

But the biggest issue with nuclear reactors is more the necessary safety containment housings and safe fuel storage. What are they doing about this? Also, after you start using the fuel, even when shut down it takes active cooling for months/years.

This article seems to emphasize that this will reduce waste and pollution but it doesn't say anything about safety and issues with the new type of fuel.

> That seems a better word to describe that to me.

It's all relative. For example, https://en.m.wikipedia.org/wiki/Portable_computer

This is portable but not man portable.

https://www.vocabulary.com/dictionary/man-portable

Can someone explain what is going on here versus the nuclear reactors navy submarines have been using for decades? I mean I get that design may be improved. I guess I’m just reacting to the notion that a portable reactor is this new achievement, which is not explicitly stated.

These are gas-cooled reactors, and much lower power output. Existing designs for Navy reactors are all pressurized water reactors that produce hundreds of MW.

There's also a challenge in waste heat. Ships have basically unlimited seawater, but they are probably designing this to use minimal (or no?) water.

Thank you :)

The US army had portable reactors 60 years ago. They were deployed in Greenland, Alaska, Antarctica. https://web.archive.org/web/20220404082426/https://www.usace...

At least some of them were produced at the Idaho Nuclear Engineering Laboratory, and one of them suffered an accident there due to operator error. That site was later renamed to Idaho National Laboratory when being "nuclear" became bad, and they're making these "new" ones, too.

Reminds me of https://en.wikipedia.org/wiki/Davy_Crockett_(nuclear_device). The US Army has done some wild things with nuclear technology.

Not exactly relevant to the article, I've always had the hope that, one day, every home would a have a "nuke ball": a dodecahedron the size of soccer ball operating as an endlessly powered electric battery.

> BWXT's design consists of a high-temperature gas-cooled reactor (HTGR) with a power output between 1-5 MWe.

I couldn't understand from the article what runs a turbine (hot gas?). Can someone explain how electricity is generated?

>The mobile microreactor would be coupled with a power conversion system that generates approximately 1 to 5 MWe using an open Brayton gas cycle

https://www.cto.mil/wp-content/uploads/2022/05/Final-EIS-Vol...

Sounds like an air compressor+turbine, but heated by a heat exchanger instead of burning fuel.

Note IANANE (I am not a nuclear engineer) but most probably by using a closed Brayton cycle. The gas is heated which expands and drives the turbine, the hot gas is cooled via a heat exchanger, compressed then fed through the reactor again.

https://energy.mit.edu/wp-content/uploads/2017/02/2-3.-HTGR-... has a diagram on page 2 that explains it better than I can

Couldn't they buy one from the Navy?

As a bonus, you can let it explode in enemy territory and said it malfunctioned ...

It's not nitroglicerine, it's fucking hard work to get a regulus to go supercritical. No plausible deniability if it does, you'd have to design it totally differently.

You just hit it with some other bomb/missile. You think the government doesn't lie?

It still won't explode, any more than a container-load of jet engine parts would if you hit it with that other bomb/missile.

It will blow up and spread radio active material everywhere. Same as if it blew up on it's own. It's not going to be a nuclear bomb. I think that goes without saying..

If you’re doing straight up war crime level things it’s much easier to just go the biological or chemical route with the added benefit of not making the land completely unusable for millennia.

That's the Hollywood view, you're getting that from a movie. Get it from the books, I recommend Richard Rhodes's The Making of the Atomic Bomb and The Turing Cathedral.

> bell-cot - It still won't explode, any more than a container-load of jet engine parts would if you hit it with that other bomb/missile.

Anything that you hit with a bomb would explode... that's the definition of a bomb... and it would spread radioactive material (in this case).

thanks for telling me that it is not nitroglycerine... as if I didn't know... I could make nitroglycerine to spread radioactive material though (you only need a couple of ingredients (3))... I would go for nitrocellulose though...

A modern military has a lot of scarce / complex / expensive equipment that it could crash / set fire to / try to explode in enemy territory. In movies, that looks really cool. In the real world, that's why armed forces carry all those cheap (at least relatively) bullets / bombs / shells / etc. into enemy territory.

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