a super lower output (1-10kW-hrs) reactor design?

General discussion of thorium and nuclear energy.
JAK
Posts: 20
Joined: Apr 29, 2011 10:08 pm

a super lower output (1-10kW-hrs) reactor design?

Post by JAK » May 01, 2011 9:27 pm

well i only just jumped into the LFTR scene after watching that thorium remix 2009 video. Having been a half-nuclear engineer from the start due to my long standing interest in fusion power, nuclear energy, and nuclear chemistry, i had a good grounding going into that video. And holy cow, everything about the lftr seems fantastic.

so fantastic that i'm very seriously considering making my own, as a power source for my house!

I went about looking up the components and legality of owning the fuel ect. but before i ask any dumb questions, has there been any attempt to design something this low powered? I'd love to get away with a core volume of less than say 100 litres if that's even possible (i'm not sure if there's some manner of "minimum distance" the fast neutrons need to pass through the graphite moderator in order to fissile effectively.)

of course the entire thing would have backups galore, almost all of them set to dump the fuel salt just in case. Leak in the fluorine gasifier? dump the fuel salt. pressure getting too high in the core? dump the fuel salt. One of the pumps having that polymerized oil problem the MSRE had? dump the fuel salt. one of the lights on the control panel blinking wrong? dump the fuel salt. With the reactor so easy to restart, it's not even an issue.

I already called the NRC and ORNL and chatted with some folks. U233 is legal to own in volumes less than 200 grams provided you have the proper licenses. As for thorium i'm not too sure.

Hastelloy-N won't be cheap, sadly. but i'm curious if there are modern alternatives to it which would withstand the neutron flux, heat, and fluorine corrosion.

It'd be great if i could fit the entire thing in the area of a standard shipping container, buried underground for radiation containment.


I'd hate to wait around, sitting on my hands waiting for some huge corporation to get the hint and start producing these. A backyard experiment could really drive home how safe these are.

Wilson
Posts: 104
Joined: Apr 23, 2011 8:47 pm

Re: a super lower output (1-10kW-hrs) reactor design?

Post by Wilson » May 01, 2011 10:58 pm

If you do it in your back yard , don't get caught or its straight to jail for the rest of your life.

Why not do it 200 miles from a coast line. You can make the reactor on land. Just don't add the thorium until your 200 miles out to sea.

Wilson
Posts: 104
Joined: Apr 23, 2011 8:47 pm

Re: a super lower output (1-10kW-hrs) reactor design?

Post by Wilson » May 01, 2011 11:06 pm

One could make synthetic fuels 200 miles from land and forget all the red tape.

JAK
Posts: 20
Joined: Apr 29, 2011 10:08 pm

Re: a super lower output (1-10kW-hrs) reactor design?

Post by JAK » May 02, 2011 12:04 am

well that's the big question, how much U233 can i have in the reactor, how much thorium, and what can i do with it (legally)

i might pair up with a university for the research in order to possibly reduce costs as well as licensing fees.

Forge
Posts: 16
Joined: Mar 17, 2011 7:49 am

Re: a super lower output (1-10kW-hrs) reactor design?

Post by Forge » May 02, 2011 3:44 am

The backyard battery. Core drill a 600 diameter hole down 5 metres. Core drill a 100 diameter hole down 50-100m as a heat sink. Lower in your BYB. Cables run power to the surface. 5kW on tap for the next 20 years.

Nice idea, but ... is a 200g fissile load reactor possible in any form?

JAK
Posts: 20
Joined: Apr 29, 2011 10:08 pm

Re: a super lower output (1-10kW-hrs) reactor design?

Post by JAK » May 02, 2011 1:27 pm

Forge wrote:The backyard battery. Core drill a 600 diameter hole down 5 metres. Core drill a 100 diameter hole down 50-100m as a heat sink. Lower in your BYB. Cables run power to the surface. 5kW on tap for the next 20 years.

Nice idea, but ... is a 200g fissile load reactor possible in any form?

that's the thing, i don't know the necessary calculations
it's, again, possible there's a minimum size for the core, and it cannot go below that and still fissile

edpell
Posts: 99
Joined: Apr 03, 2011 7:50 pm
Location: Rhinebeck, NY

Re: a super lower output (1-10kW-hrs) reactor design?

Post by edpell » May 02, 2011 1:38 pm

I love the idea of a DIY LFTR. I want one to simply stay warm in the winter. If I can help let me know. I will work on understanding how small a core can be.

Sincerely
Ed

edpell
Posts: 99
Joined: Apr 03, 2011 7:50 pm
Location: Rhinebeck, NY

Re: a super lower output (1-10kW-hrs) reactor design?

Post by edpell » May 02, 2011 1:43 pm

So 200g is about 20cc of U233. Not sure where your 100 liters comes in? Do you plan on one fluid or two fluids. That is will the U233 mix with the thorium? Or will there be a core of U233 and a blanket of thorium? I like the two fluid designs they are cleaner.

edpell
Posts: 99
Joined: Apr 03, 2011 7:50 pm
Location: Rhinebeck, NY

Re: a super lower output (1-10kW-hrs) reactor design?

Post by edpell » May 02, 2011 1:55 pm

The bare critical mass for U233 is 16Kg. Getting 0.2Kg to be close to critical is going to be a challenge. May need an external neutron source (al la Carlo Rubia).

USPWR_SRO
Posts: 489
Joined: Apr 24, 2008 4:54 am
Location: Columbia, SC

Re: a super lower output (1-10kW-hrs) reactor design?

Post by USPWR_SRO » May 02, 2011 3:01 pm

Good luck with that.

If you are a US citizen the NRC will claim jurisdiction on you anywhere you are unless you are in another country. It's one of those little gotchas in the Atomic Energy Act of 1954. I agree it sucks but there it is.

I dunno about non US countries regulation of nuclear materials.

JAK
Posts: 20
Joined: Apr 29, 2011 10:08 pm

Re: a super lower output (1-10kW-hrs) reactor design?

Post by JAK » May 02, 2011 4:49 pm

edpell wrote:The bare critical mass for U233 is 16Kg. Getting 0.2Kg to be close to critical is going to be a challenge. May need an external neutron source (al la Carlo Rubia).
someone on another forum suggested a neutron source to supplement the reaction, but i'm not sure how powerful it would need to be.

16kg minimum for criticality? does that account for turning the fast neutrons into thermal neutrons?
but then again, 35 pounds isn't that exacting, too bad the stuff is horrifically illegal.
I wonder if i could team up with the nuclear engineering division of a college, perhaps allowing for slightly cheaper materials (i'd need AR-15 nuclear grade graphite, apparently a one foot cubed chunk would run me a face-melting $1,200. this isn't even accounting for the cost to manufacture hastelloy into pipes) and access to the more taboo stuff.

could an advanced, modern ceramic be used to line the pipes? or would that not play well with neutron flux?

Ida-Russkie
Posts: 490
Joined: Aug 29, 2008 4:55 pm
Location: Idaho Falls, Idaho

Re: a super lower output (1-10kW-hrs) reactor design?

Post by Ida-Russkie » May 02, 2011 9:22 pm

Heck someone on here might turn you in for the reward. Its think its 250 k for having special nuclear material, the last I checked.

JAK
Posts: 20
Joined: Apr 29, 2011 10:08 pm

Re: a super lower output (1-10kW-hrs) reactor design?

Post by JAK » May 03, 2011 1:26 am

Ida-Russkie wrote:Heck someone on here might turn you in for the reward. Its think its 250 k for having special nuclear material, the last I checked.
good thing i'm not touching a microgram of the stuff until i can make SURE it's legal.

Forge
Posts: 16
Joined: Mar 17, 2011 7:49 am

Re: a super lower output (1-10kW-hrs) reactor design?

Post by Forge » May 03, 2011 2:49 am

I thought about this for a little bit today. General reading here and elsewhere indicated that generally, higher purity, higher density, higher temperature are all associated with smaller size.

No point trying for breeding. No point trying for near criticality.

Anyway, I'm still learning about this stuff and someone mentioned MIT courses online. So went over and had a squiz through, and saw some stuff on plasma physics. Ah, fusion. But.. why limit plasma work to fusion? Can a fission device work as a plasma circuit?

Turns out some people are looking into this sort of thing as a space power source.

But.. getting back to a micro device, why not a small plasma circuit (is there such a thing?) circulating thorium? Add a neutron beam (is there such a thing at small scale?) and a MHD generator.. power?

So. 200g of material, circulating in a plasma circuit, with power developed and modulated by the intensity of a co-linear neutron beam.

Looked up thorium and plasma and found vague references to a thorium plasma battery, but no real info.

Anyway, a random, uninformed idea to throw into this discussion.

dezakin
Posts: 280
Joined: Dec 20, 2006 7:50 pm

Re: a super lower output (1-10kW-hrs) reactor design?

Post by dezakin » May 03, 2011 2:09 pm

Ludicrous speed, go. The question being asked by original poster is isomorphic to 'Hey guys, where can I get weapons grade material to run an unshielded reactor without containment at my house ? By the way, does anyone know the best way to get the timing right on a spherically symmetrical implosion device?'

While think the antiproliferation argument is a bunch of nonsense for powers that allready can build their own weapons, I have a sneaking suspicion that laws preventing people from making atomic weapons in their basement might not be a terrible idea.

Post Reply