I know what I want for Christmas …
My very own nuclear power plant!
I wonder how much the city land fill will charge me to take this off my hands when it wears out?
200 kilowatts? I bet a lot of businesses would like that… but getting the zoning approvals will be interesting.
All I want for Christmas
is my two front teeth (glowing bright green)…
Think of the money you’ll save on nightlights! 
These beauties are pretty cool. Negative power density means that as it heats up, reactivity goes down (so no meltdown is possible). It has a solid core assembly, a neutron moderating sheath that has to be lifted to shield the core assembly and start the reaction. To SCRAM the reactor, just drop the moderating ring and it stops. The core consumption rate depends on the level of heat energy extracted, and refuelling replaces the entire core assembly, and can be shipped off for recycling or disposal.
It’s not the simplest or smallest reactor design. A recent design published uses Uranium Hydride fuel and Helium coolant and has no internal moving parts. It maintains a constant temperature, and sucking heat off to drive a generation unit increases the reaction rate. Stop cooling and the reaction drops off to a low level again.
There are lots of places where these sorts of power plants can be really useful. A huge amount of power generated is lost in long distance transmission. Generating power locally is much better than running cable, and these are great base-load generators.
Si
Here’s an article about what appears to be a pilot project involving similar technology (I don’t buy that 200 watts is enough for a whole village, which is why I say it’s only similiar.) being planned for an Alaskan native village.
The questions I’d have, first, is what’s the cooling/moderating medium for the reactor?
And, of course, how will waste be dealt with?
Other concerns for residential uses: Are they going to be shielded in a sphere? Or does one have a huge liability issue to try to keep neighborhood kids off the silly thing?
FTM, can you imagine the witch hunt civil suits? “Ever since the Jones put in their Spawn of Satan, I mean their reactor, the milk my cow Bessie has been putting out has tasted funny. They put a hex on my cow, they did!”
This is the Toshiba reactor referred to in the OP.
Liquid Sodium. Nasty, reactive stuff of course, but it lives in a sealed core unit and relies on convection, so no pumps. It maintains the negative power feedback - the hotter the sodium, the less well it moderates the core, and reaction rate falls, reducing temperature
The entire sealed core unit gets replaced by the manufacturer and shipped for disposal or recycling (a much better move in my opinion). You don’t even need to open it to dump it. You let it sit for a few years to allow short halflife stuff to decay before reprocessing. Because there is little internal engineering, you don’t have to do complex stuff to reprocess the core material (like stripping cladding from rods and stuff).
Inground installation seems to be the favoured method. All you have is some couplings for the steam generation unit and monitoring systems. The only moving parts relate to the moderating ring that gets jacked up over time as the core gets depleted. If that jams, you pull the core to service the rest of the system and reinsert the core. These are civil installations - like a big power distribution and transformer complex. It needs some security and high fences, but not a huge amount. Certainly no radiation risk in normal operation.
Si
I’m inclined to agree, but that’s going against current US policy, so I wonder how well that will work in the US, at least. (I understand why the choice has been made, I just think it’s short-sighted.) I’d been thinking more about how the waste will be processed when returned to whatever collection facility Toshiba uses for the spent cores, rather than for the end-user. Shipping back to a manufacturing/reprocessing facility in, say, Japan would worry me, just for the questions of security while in transit; but in the US trying to do anything with the core would be difficult from a public perspective.
Thanks for the information. I tried getting more from Toshiba’s website, but had no luck.
And given my own background, while I’ve got no real objection to a small reactor next to my house… making it liquid sodium cooled gives me the heebie-jeebies. 
At last! A practical way to power the electric car!
Exactly!
Ahh. What could be nicer than curling up with the one you love on a cold night, and bask in the blue glow of Cherenkov radiation from your own reactor’s “swimming pool” cooling system, confident that the self-contained convective loop of highly corrosive liquid sodium probably won’t spring a leak and start reacting with the cooling water?
But think of the fun you can with an at-home planetarium show on the inside of your Horton Sphere .
(The D1G ball at the Navy’s NPTU in West Milton, NY was originally built to contain the explosion that would occur from a failure of the S1G prototype’s liquid sodium cooled reactor plant.)
Cue outraged, incoherent, ignorant response in three… two… one…
(Not here, probably. In the media. From the people who think cell phones are giving people brain tumors and wouldn’t know the term “non-ionizing” if it failed to give them a carcinoma.)
But will it be enough to send me back to 1955?
BAH!
The Farnsworth Fusor will replace it…after a little refinement…oh my, yes… 
It’s nuclear! I’m afeered! What if it…EXPLODES!?!
You’ll get superhuman powers and the sudden urge to wear a cape.
I’ll take two, in that case.
If you can get it up to 88 MPH!