TRISO Fuel?

[brockrwood]

Tiny nuclear fuel cells? Inteteresting.

https://news.sky.com/story/bangor-u...uel-for-nuclear-reactors-on-the-moon-12955003

 

[dhbarr]

Kairos, Westinghouse, and X-energy are all mentioned as companies investigating Uranium Oxycarbide, though not necessarily for this particular use case.

 

[prfesser]

Had to look up TRISO. Not sure what the big deal is. Sounds like it's been in use for some years. A German plant started commercial energy production using TRISO in 1983, though it had to shut down a few years later. I didn't check the circumstances of the shutdown. They seem to be working on a new version of the pellets.

I have wondered...apparently a serious problem for a moon base is loss of heat at nighttime. Surely a feasibility study has been done on using a Pu-238 power-and-heat source? If pelletized-fuel reactors can be made small and efficient enough...

 

[TNmike]

Triso-X? They are going to build a build a plant about 5 miles from my house.

 

[Kyle Goodwin]

The current Triso particles are part of the next gen gas cooled reactors with a focus on safety and accident tolerance. As for the moon DOE and NRC are looking at a sodium cooled sterling reactor because it will work well in low gravity and low pressure environments. Plutonium RTG's have an issue of proliferation concerns so the government doesn't like us making a ton of plutonium at a time. If you guys are at Balls this year come find me (I am flying a AGM-33 8 in pike for my lvl 3 cert) and we can talk more about the Triso stuff. Where I work we are currently irradiating the particles to see how the uranium migrates through the graphic as it ages.

 

[aerostadt]

The current Triso particles are part of the next gen gas cooled reactors with a focus on safety and accident tolerance. As for the moon DOE and NRC are looking at a sodium cooled sterling reactor because it will work well in low gravity and low pressure environments. Plutonium RTG's have an issue of proliferation concerns so the government doesn't like us making a ton of plutonium at a time. If you guys are at Balls this year come find me (I am flying a AGM-33 8 in pike for my lvl 3 cert) and we can talk more about the Triso stuff. Where I work we are currently irradiating the particles to see how the uranium migrates through the graphic as it ages.

So, can the TRISO particles can contain the decay products?

 

[Kyle Goodwin]

Yes, the actual Triso particle is actually several "shells" that inhibits the migration of fission product daughters thereby limiting the possibility of release. We have done accident testing on them and they are extremely robust and pretty hard to break.

 

[prfesser]

Looks like Hackaday has an article that has a little more info on TRISO, as well as links to a more robust description and history, and to nuclear fuel processing in general. This is interesting stuff! (lifelong learning = good)

Hey @Kyle Goodwin, I thought that the Pu-238 in RTGs couldn't easily be used for a nuclear device. Also read that its presence in Pu-239 can actually inhibit the detonation process. (My thought processes these days are akin to the urban legend about goldfish; a three-second memory. )

 

[Kyle Goodwin]

So it has to do with proliferation. If you can make Pu238 its not that hard to take it that last bit up to Pu239. At ATR we convert neptunium into Pu238 for use in RTGs. Here is an article from Oak Ridge about our process.

 

[Spacedog49Krell]

Sounds similar to the uranium/uranyl carbide ceramics I experimented with in 1967. It looks great on paper and early testing. Until it is bombarded with neutrons. The splitting of the uranium atom physically and chemically breaks up the crystal lattice. In the physical location of one atom you now have two atoms. The lattice structure breaks down and the fission by-products migrate. The multiple layers of material on the pellets are there to mitigate the physical and migration issues. I've always had great hope for the concept.

 

[Kyle Goodwin]

Yeah so we are testing the next gen accident tollerant fuel for the NRC and commercial plants also right now. Because we have scanning electron microscopes and other equipment to see the actual atomic layout and migration of fission product daughters. This is causing alot of questions from the NRC about fuel life cycle and migration through the current fuel in use. On a side note, the reason the moon mission is also not looking at RTGs is power capacity. Right now and RTG is good for 300 watts or so. Now size isn't too much a concern on the moon but the sterling engine they are working on is 10 kilowatts with plans for up to 40 kilowatt designs.