Teenager Designs Safer Nuclear Power Plants
accuweather.com
accuweather.com
As I grew older, I later learned that the inability to "turn off and on" a nuclear fission power plant is a big problem for jurisdictions (like Ontario) where nuclear power is a major source of power. It's not uncommon for the price of power to turn negative in decentralized power markets during periods of low utilization. (It's easier to pay someone to shut off a coal/hydro/gas reactor than to shut down the reactor and then have it down for weeks before you can turn it back on again.)
Regarding the kid's idea, building things underground is, in and of itself, a tricky task that I'd want well-trained engineers working on. There's the risk of tunnel/shaft collapse causing death. There's also the issue of the water table and figuring out where to build it such that it doesn't contaminate the groundwater. I suspect this'll increase the cost more than he expects.
Then again, I also grew up being taught that CANDU reactors are way safer than most reactors in the US, which use carbon control rods (think giant thick rods of pencil lead that could catch fire), and that nobody in the US builds them simply because of cost reasons. I have no idea whether that reasoning is true or not, though. :/
This is in no way an area of expertise for me, so somebody please correct me if I am wrong, but I am under the impression that graphite moderated reactors are not, and never really have been, popular in the US; graphite moderated is more of a Russian thing. Most reactors in the US are water moderated (besides whatever the military is operating perhaps?).
Also I don't think graphite or any other form of carbon has ever been used as control rods.
https://en.wikipedia.org/wiki/RBMK#Control_rods
Other than that I think you're completely right.
Sunlight is overrated. :(
I've heard in South Korea many of the smaller apartments don't have any windows at all.
Those are generally not considered objects of aspiration.
Once up in the building (the 10th floor if I recall), I worked in a windowless part of the building. Lunch was eaten in the underground mall and sometimes dinner and the occasional happy hour.
After work I'd reverse course and in the summer pop up above ground just in time to see the sun setting, and in winter darkness. I never made it back home during daylight.
It was kind of cool for a while, I went weeks without ever seeing the sun, I felt kind of like I lived and worked in a nicer version of the world of THX-1138.
But after a while it slowly started to drag and become depressing. A year in and I was clawing at the walls for a change of scenery and routine. I used to make an extra effort to take a walk above ground during lunch just to get a few minutes in the sun, I'd play hooky and leave early so I can get a half hour in the sun at home. It was a strange experience.
Except when we dig out all the fuel necessary for this (I know, this plan wants to use existing material, so this has already happened - but still, contamination is contamination). That part is always conveniently glanced over. Or when we need to store the waste, a problem that is still unsolved (I did not see anything mentioning that this will produce non-radioactive waste).
Yeah, apart from that, clean as anything.
"In other words, all the highly enriched uranium and weapons-grade plutonium collecting dust since the Cold War could be put to use for peaceful purposes."
So take the stuff that we are struggling to deal with now and distribute it far and wide across the land, underground. Got it.
"...this could be the source of energy that provides carbon-free electricity."
Well thank god it doesn't produce carbon emissions, one of the easiest to manage climate problems we have.
"So I really think that in the, say, 20 years it's going to take us to get fusion and make fusion a reality..."
Oh wow, it's like the six degrees of pipe dreams.
Look - I'm really all for fusion. If it ends up working - great. Throw out billions to get there? Be my guest. But how about, in the meantime, we invest money in technology that only produces pollution that we know we can manage. Because then, if our pipe dream fails, we are left with stuff that actually works. Not thousands of waste nightmares buried deep across the soils of our childrens' future.
You bet your ass it does. I wouldn't want to live within a hundred miles, but at least we only really need one such dig site for the planet. Economics being what it is, there are more, but not a lot.
Now go look at a coal mine, and multiply the damage that does by the number of mines.
We can't eliminate all damage. We can minimize it, for which nuclear power is helpful.
In larger picture these side streams don't matter much. What happens in Kazakhstan's (36% of all U production), Canada's and Australia's uranium mines does. They account for 64% of global uranium production. Australia has 23% of the world's uranium deposits, CAN 12%, KAZ 10%.
About 85% of current needs are met with digging, 15% comes from secondary sources.
It's interesting that two of the biggest producers of uranium do not utilize nuclear energy themselves. Even Canada produces only 12% of their electricity with nukes (France 78%). Good business even if you don't personally believe in it?
I notice the article doesn't reference waste. That's because its a non issue ever since we here in australia came up with a state of the art solution that finally puts the matter to rest: we're building a dirt road out to a small, remote, economically disempowered and politicially disenfranchised community of traditional land owners. At the end of the road, we're building a barbed wire fence, that surrounds a shed. Problem solved.
Its cat and mouse or white hat vs black hat.
The existing worldwide system uses U to make Pu to go boom, more or less. Th doesn't make Pu so existing experience and practice means no boom, at this time. The problem is it does make an alternative U isotope that can eventually go boom although not much research has been done on that because it sucks as a fuel compared to U so no one has bothered to use it yet on a wide scale.
I figure if you deploy Th reactors "widely" you've got about a decade or two of semi-guaranteed non-proliferation before the reprocessing / industrial base builds to make boom. Not sure if thats really worth anything as we still have the existing U infrastructure so we're not going to save any money. In the long run the situation is probably worse because now there's two channels to watch.
Its also a WWII German "big lie". As the USA shows, you can do U as a fuel without reprocessing, where stuff that goes "boom" can be diverted / stolen / skimmed. In other words implementing fuel reprocessing (presumably of U) means opportunity / costs WRT "boom". On the other hand Th more or less requires reprocessing. So overall world safety will decrease if you do Th because you have to implement a reprocessing plant. Its a false dilemma. You can cut off your leg or your arm, with different lifestyle changes, which is worse? Hmm, why not cut off neither? Well we're not going to talk about that option because, um... just because.
For various reasons, a liquid thorium reactor burns almost all its fuel. It's easy to remove fission products that poison the reaction by absorbing neutrons. Some of those products are gasses, which damage solid fuel and prevent you from fully using it; with liquid fuel they simply bubble out. Also it produces less transuranics in the first place since it's fissioning U233 instead of U235.
So you're able to fission most of your fuel, and your waste is just the fission products. There's a lot less of that, and in a couple centuries they're back the radioactivity of the original ore.
Regarding proliferation, the main advantage is that you're shipping non-fissile thorium to the reactor, and non-fissile fission products away from it. The reactor itself can't do much more than replace its own fissile inventory, so if a country without uranium enrichment were to start siphoning off fissiles, their reactor would shut down and they'd need to beg for help to get it restarted.
Aside from Oak Ridge's pioneering efforts fifty years ago, there are several startups in the U.S, one in Canada, a billion-dollar effort in China, and additional work in several other countries.
UPD: Switz tried to make underground reactors and got what is now the most contaminated cave in the world. http://en.wikipedia.org/wiki/Lucens_reactor
also, the underground thing worked - no ? it contained the radioactivity - wikipedia says no pollution occurred... in the case of a ground level one, I'd guess the Vaud canton would be pretty f-up
Well you see there's design, like I designed a giant spacecraft when I was a kid, all on one piece of paper, and then I talked to people about it because I thought it was cool, and there's "really design" like handling mfgr issues, clearance/fit/wear issues, failure tolerance, etc. Thats how my spacecraft only took one side of one piece of paper but the Cessna I took lessons in had about six linear feet of shelf space for the A+P manuals for all the different parts and subsystems thats just enduser maintenance stuff, not actual design docs. I haven't watched the video, but my guess is the kid doesn't have a design of his own. If a design of a real reactor takes 1000 engineer-years from the best minds in the field, and the kid is not that old yet...
I've had kind of a nuclear interest for quite a bit longer than the kid's been alive. Its an interesting hobby, seeing how much you can learn. As a hobby its no weirder than seeing how much you can learn about the phone system, or the internet.
The fundamental problem we're discussing is balancing optimum nuclear characteristics (neutron activation, long life, capture cross section, etc), mechanical/chemical/safety/lifespan properties, and mfgr/supply issues, can never really optimize all three at the same time.
The Lucens reactor local optimization maxima for fuel cladding (the tube/shell the fuel sits in) ended up as Magnesium. Get it hot enough and it burns spectacular in pretty much anything, CO2, air, water... Also it corrodes pretty well underwater, or heck even in air. So burying a super flammable fuel underground and heating it up isn't so wise in retrospect although I'm sure as a local maxima it looked like a good idea. If we lived on an oxygen free planet then Magnesium would be quite a handy general purpose metal. Unfortunately on the earth...
Other popular fuel cladding over the years for gas reactors has been stuff like beryllium (WTF were they thinking?) and stainless steel.
I suppose the guys who selected Mg for cladding did pat themselves on their backs for not using a Be based cladding, which is probably the only way it could have turned out worse.
Needless to say, stainless steel in CO2 doesn't burn very well. Maybe that's the kids design, its certainly off the shelf and fairly conventional. Lifespan might be shorter, ruinous cost, and the worst part is stainless eats neutrons for dinner which aside from making a short life means huge waste of fuel and heating issues, its kind of like storing your fuel inside shielding crazy as that sounds. But as a local optimization its not bad for mfgr safety as stainless is pretty harmless (Your cafeteria is contaminated with stainless steel, oh noes!) and the flammability rating of stainless steel in CO2 atmosphere is as you'd guess pretty excellent.
Why all this fooling with cladding? Fundamentally nuke fuel seems to be awful structurally so you shove it into a pipe. Engineers are pretty cool with making heat exchangers outta pipes so a magic pipe that generates its own heat is pretty well understood. Its an object oriented encapsulation idea, sorta. If you made an indestructible fuel that didn't need cladding, then you'd either have wear issues on whatever it touches and/or processing/reprocessing would be terribly difficult dangerous and expensive and contamination issues so you'd just be moving the location of the accident, not reducing the rate of accidents.
Kirk was the first guy who introduced me to the idea that our current electrical generating plants are incredibly inefficient. Sadly, it seems no one (who is in a position to do anything about it) really cares. That could be because they know things we don't, or it could be because they're paid (as in they have no incentive) not to care.
1) People use fuel type as the identifier but exclusively talk about reactor design WRT safety and economics and efficiency and all that. A 1960s uranium BWR will, in fact, suck, compared to a 2000s thorium exotic design. Both will also suck compared to a 2000s era uranium exotic design. There's a hilarious stack exchange on this topic WRT whenever you hear someone talk about fuel choice you can assume they know nothing about chemistry or physics and are actually talking about reactor design. There is some linkage of course. You need a fast reactor to breed U which pretty much means sodium coolant but you can breed Th with thermals which means a more controllable reactor, etc.
2) See #1 now WRT big scale system design issues. Existing system in the US is to not reprocess. Hmm if we switch fuel to Th we'll have to reprocess to do it at all. Well if we use Th we'll therefore have less waste. So what. If we reprocessed U we'd also have less waste. But we don't reprocess. So either Th isn't happening as an executive decision, or if it does happen the only way it can "win" if executive decision not to allow U reprocessing, so that the .gov (instead of .com) can select the winners and losers.
3) Lots of optimization of trees at the expense of the forest. So the cheapest part of running a reactor is the fuel, and you'd like to save fuel why switching to Th. Uh... OK. Well Th neutron economy in the core is awful, you don't get as many n as from U, so you have to "make up for losses". No problemo, if too many n are eaten by structure, just use less structure, make it weaker, thinner, shorter lifespan, not as strong. Whoops you've now optimized the cheapest part, the fuel, to be a bit cheaper, at the cost of ballooning the four most expensive parts of running a reactor, that being building costs, design/approval, maintenance, and disaster recovery. Doomed. Just doomed.
4) There are proliferation issues with Th that are "somewhat" worse than the U system. Not insurmountable, just twice the work and headache. In this way its like switching from imperial measurements to metric. In theory as small long term gain, but the short to medium term PITA makes it never happen. Slow evolution, maybe, maybe not. Revolutionary leap forward, um, no, not gonna happen.
Regarding your second point, there's no traditional reprocessing with this reactor when using thorium. You start it with fissile fuel, then simply keep adding thorium, which is converted to U233 inside the reactor.
But what I really think is we should be focussing the effort on local energy need, far more seriously. Like, establish real neighborhood energy systems that use the energy that is in the neighborhood - if its solar, solar. If it is thermal: thermal. If it is wind: wind. If there are none of the above sources available for your house: MOVE!
All of the tech exists for an average house-hold to step off the grid, and it really is mostly a matter of minds being changed about the 'culturally acceptable reality' of how we manage our energy-driven lifestyles.
I, for one, welcome the day when I can compute without having to ever once plug my laptop in, because its case is in fact no longer a dull grey oil-debt, but rather instead a highly efficient solar panel, and I look forward to using a 'slow system' if the CPU itself has evolved into an extremely lean - yet fully functional - current sink that gets along with whatever sunshine is available. I yearn for a complete dirth of chemical-derived power for my computing needs.
Hopefully, the day will come when stepping off the Grid is as easy as, once, the revolution that occurred when millions of us were suddenly able to carry around 20,000 songs in our pocket, access any knowledge, anywhere, and talk to anyone we chose to, any time, at a flick of a swish ..
And - does anyone really use their computers in the sun?
Other than that, I do agree with you that neighbourhoods should use local energy - but can we rely on purely natural energy? The wind doesn't blow all the time, the sun doesn't shine at night, and thermal energy isn't always available.
So I lust for the solar-powered mini-PC's that seem perched out there on the horizon.
This is why I say we must combine the effort to reduce the grid dependence by enduring mobility. Yes, the Planet has a non-uniform distribution of most resources, but the big fat problem with our energy use today is that we stay in place to use it. Indeed, cities do have to consider their location on the planet in the grand scheme of things; the means by which these cities expand/contract/endure/reduce is entirely an energy business.
My feel, is that any cultural event which occurs to reduce the dependence on a long-distance chemical eco-system, is going to be a way out of the mess. If computers can rapidly leap to the point where the Grid connection is made irrelevant, because computing is happening with the energy resources available to us in the near spectra, for free in the sense that we are not stuck in produce/consume loops everywhere, then we will have ourselves a lighter time of the days ahead.
I'd be quite happy to return to 8-bit computing if it was on a small device that harvested my daily jogging routine. Go for a jog, check e-mail. Finally a proper user interface.. ;)
It is also inferior to the thorium fuel cycle based Liquid Fluoride Thorium Reactor (LFTR), a prototype of which ORNL did actually create and which has been widely espoused by Kirk Sorensen, formely of NASA, for seven years already.
Yet Kirk Sorensen gets a TEDx talk and a 14-year old gets a TED talk...
Reactors like this produce far less waste (for reasons I've detailed in another comment here), and you can also use them to burn up most of the waste we have right now.
No argument on political difficulties though.
...and then what?
Did they seriously think that putting reactors underground is a new idea?
This material is very much not "collecting dust on shelves". Under the "Megatons to Megawatts" program the US has spent a considerable amount of money to acquire highly enriched Uranium from Russia, from decommissioned warheads, and has reformulated it into fuel rods. The US does the same thing with its own decommissioned weapons.