Toshiba Micro-Nuke: Real or Photoshop?
by Lloyd Alter, Toronto on 01. 2.08
All the geeks are agog over the new fun-sized Toshiba Micro Nuclear reactor (shown on left) that Engadget says "details are slim" but "Toshiba's Micro Nuclear reactors are designed to power a single apartment building or city block, and measure a mere 20-feet by 6-feet. The 200 kilowatt reactor is fully automatic and fail-safe, and is completely self-sustaining. It uses special liquid lithium-6 reservoirs instead of traditional control rods, and can last up to 40 years, making energy for about 5 cents per kilowatt hour." Geekologie says "The first unit is being installed in Japan in 2008 and if regulation allows (read: get f****g real) they'll be available in the U.S. in 2009"
We think it looks suspiciously like the 4S reactor we showed on TH two years ago, picture on right.
TreeHugger Meaghan covered a proposal to install one in Alaska and said at the time "the 4S reactor ("Super-Safe, Small, and Simple"--Wow! Genius marketing, right?!) will make it the tiniest reactor ever built, about the size of a large spruce tree. With an underground reactor core encased in concrete housing, this baby’s as safe from attack or theft as “a missle in its silo."
Toshiba calls its design the 4S reactor, for "super-safe, small and simple." It would be installed underground, and in case of cooling system failure, heat would be dissipated through the earth. There are no complicated control rods to move through the core to control the flow of neutrons that sustain the chain reaction; instead, the reactor uses reflector panels around the edge of the core. If the panels are removed, the density of neutrons becomes too low to sustain the chain reaction.
The design is described as inherently safe, but it does have one riskier feature: It uses liquid sodium, not water, to draw heat away from the core, so the heat can be used to make steam and then electricity.
Designers chose sodium so they could run the reactor about 200 degrees hotter than most power reactors, but still keep the coolant depressurized. (Water at that temperature would make steam at thousands of pounds of pressure a square inch.) The problem is that if sodium leaks, it burns."
We didn't think much of it at the time, and suspect that someone is playing photoshop games on Engadget now- a sodium cooled nuke in your basement is about as likely as a nuclear battery. ::TreeHugger
While i probably wouldn't be comfortable with an untested technology like this in my backyard, doesn't treehugger have a responsibility to be objective and informative? The emotional and biased tone of this article seems unprofessional.
While nuclear is controversial, one mustn't forget its benefits of producing large amounts of electricity without GHGs. We need all that we can get to get through this, so emotional outbursts seem to have less of a place in trying to find solutions than logic and common sense.
The bigger problem with sodium is that it reacts violently with water. So if there's a leak in the heat exchanger between the sodium and steam loops you have a sizable issue. This usually requires a primary and secondary sodium loop which is also necessitated by the high energy gammas produced by Na-24. This usually adds a lot to cost. The big benefit of sodium as a coolant is that it can fairly easily be designed to be passively safe.
The problem with small reactors in general is in order to operate for extended periods of time they need higher fuel enrichments which is a greater proliferation risk.
I agree that this proposition is unlikely here in the U.S. would be interesting to see the designs and the potential applications are numerous. I can't see this ever being approved by the NRC for use in "your basement", but for civil applications which require quite a bit of power (auto plant, or desalination plant, or remote outpost) it could be very beneficial.
I agree with the first commenter.
There is no need for biased remarks. Objectivity is what we need.
Well, now the terrorists won't need to send a nuke in a shipping container, they'll just dig it out of your back yard - or blow it up where it lies. Just as good.
The stupidity of this - IT BURNS!!!
Nuclear plants are really just fossil fuel sinks, when you factor in all the energy investments in mining and refining the fuel, and constructing the plants. Having lots of small ones just means that you lose any economy of scale, which is all that nukes really have going for them to begin with.
Nuclear waste anybody? Now's your time to step forward to claim your share. No one liked it when Dixie Lee Ray suggested everyone keep their share of it in the basement, problem solved. It's so safe, you know.
What happens when ground water seeps in and comes in contact with nice, hot sodium? Oh, that's right, it explodes. I'm sure Toshiba will make their welds and metalwork of the highest quality. But, having had my little LiIon cammera battery explode while recharging - with the force of a shotgun shell - I'll pass on the opportunity.
Could you guys please get back to focusing on distributed renewable power generation. You know, something that might actually do its job and not kill us or give us cancer in the process? Thanks.
How is GROUNDWATER going to seep into the primary or secondary cooling loop? That's just absurd. I haven't seen the coolant loop design so speculating on that is kinda useless, but there are studies for the IFR for sodium explosion scenarios so you can perhaps reference them.
As for welding, in the U.S. the welds must be performed by an NQA-1 certified professional coupled with proper inspection and testing, not half-ass on some assembly line in a foreign country. Testing usually involves rigorous Helium leak check to at least 10^-8 atm-cc/s and die penetrant testing, all of which must be certified by the NRC.
If terrorists were somehow able to get the nuclear material in this thing... 1) There's not enough material present for a bomb 2) they'd still have to enrich it to something like 95% and 3) Build the rest of the bomb around it to actually function (hardest part of the entire proliferation process).
You're more likely to give yourself cancer by simply existing. Every second ~4000 K-40 nuclei in your body decay emitting high energy 1460 keV gammas and 50 C-14 nuclei located in your DNA decay and transmute into nitrogen. You're talking about getting cancer from a buried, heavily shielded, relatively low activity reactor, the probabilities just aren't there.
I think a little sarcasm never hurt anyone.
I don't mind a little 'personality' injected into the articles. Nice to see a little humanity.
Maybe decommissioned nuclear aircraft carriers could be used as power stations - You have a reactor right there (proven as well), plus a lot of space to mount solar panels, and room for a couple of wind turbines on the tower. OK, maybe I am being silly ... but no more silly than a big private Hummer in civilian hands at $100 a barrel oil.
I wonder how dangerous Lithium 6 is compared with other fuels. There are also other fuels to power the regular plants that are easier to handle/deal with.
Looking forward to much more TH in '08 !!
Good Luck,
vsk
I agree. I don't see the economy or safety in such a small unit. If there is no economy in making a huge nuke plant then it seems unlikely that there is in this small unit.
I wonder about wind power for people in urban/semi urban environments. I am sure apartment houses could benefit with a few medium-sized turbines on the roof. And for houses, since bigger buildings around them tend to create high velocity winds in small areas when it is windy out, I wonder if a few AIR-X sized generators on the roof would be of benefit charging batteries while there was no sun at night to excite the solar panels.
I should just get off my whatchamacallit and do the math.
vsk
@vsk
Lithium-6 is not a fuel in this case, it is being used as a neutron absorber. The fuel is still going to be partially enriched Uranium. Lithium metal has about the same hazards as sodium metal, but to a lesser degree.
I'm very sceptical about it when it said it generates 200kw.
Give that the efficiency is around 33%, it would mean that this generates 400kw of heat at the same time, which is not easy to dissipate.
In the other hand, if it use co-generation (generating heat and electricity at the same time), it could really boost efficiency of nuke power plant.
Lord save us from people like Jon.
Abe Lincoln, thank you for debunking the FUD.
I can't even describe how terrified I am that anti-nuclear social sabateurs will force us into another 30 years of fossil fuels again - haven't you people done enough damage?!?
While not being inherently anti-nuclear. My position being that while it might be possible for the U.S. with much higher per capita GDP and lower growth rate to meet all new needs with renewables if we collectively decide to pay a little more to avoid nuclear, I don't see how developing countries like China and India can possibly meet their increasing demands coal free without relying heavily on nuclear.
That being said... I do suspect this might somewhere be a joke or mistake that has taken on a life of it own. 200KW seems too small to be economically viable for a steam turbine based generating system. Steam plants require round the clock staff and routine maintenance. I believe that is one of the issues even with the 10MW 4S (the real thing) is that the staff requirements raise the per kWh cost considerably. Wikipedia lists the estimated cost for 4S electricity at 5 to 13 cents/kWh... and the 13 is probably far more realistic. At 200kW output the cost would be WAY higher.
Bottom line... I can't imagine this is real.