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Fission in a Box
Jim Howard writes: "The The World and I magazine has an article suggesting the following interesting possibility: 'Advances in South Africa and the Netherlands suggest that small-scale fission machines could become safe, reliable, and inexpensive sources of electricity and heat for ships, factories, and perhaps single-family homes.' Well worth a look, if only for the review of nuclear power basics." Don't hold your breath, because technical obstacles aren't the main ones. But it's a nice overview of the science behind small reactors.
Youre right, but even with alot of medium lifetime elements sitting around, were still in a better position than we are now with stuff thats going to be around for a million years.
The medium-lifetime elements are what I'd worry about, personally. Anything with a half-life of millions of years isn't going to be horribly dangerous (in low doses or for low exposure times), and so could if necessary just be spread around over a very large area as dust in the air or the ocean. Its contribution to the natural background radiation would be undetectably low.
But, if you have medium- and short-lived isotopes present, you'd triple everyone's cancer rate doing that. This is why I consider the shorter-lived elements to be the main problem.
Ultimately i think some sort of crustal sequestration method would be the best, send the radioactive particles into a fault where thell be sucked into the earth.
This was my favourite solution a while back too. Then someone pointed out that it would take millions of years for them to be sucked down (moving at maybe a foot per year, and you want it to sink several hundred miles). This unfortunately doesn't look practical.
My favourite long-term solution would be to either find a way to *safely* ship them into space (you don't want a rocket to explode), or else to feed them many times through a mass spectrometer/neutron source rig (filter out the safe elements, and send the unsafe ones back into the neutron source for transmutation). Neither approach is practical now (both could be done, but they'd either be horrifically expensive, or have unacceptable risks of contamination, or both).
And think about the chain reaction that would be caused by one "going off." If anyone else in the area had one, the resulting EMP would probably fry the control electronics and cause other devices to go "critical," thereby setting them off too. What a blast that would be (no pun intended).
Um, no nuclear plant ever built in the history of nuclear power has been able to cause a nuclear explosion. Building a nuclear bomb requires completely different conditions (for reasons that I won't go into here).
The worst that happens, with any reactor, is that the core gets hot enough to melt and/or cause coolant pipes to burst. This is ugly, because it contaminates everything nearby, but relatively minor on the "explosion" scale. There is no EMP.
I wouldn't worry about meltdowns, though. Firstly, all reactors built within the past two or three decades have doubly- or triply-redundant systems that shut them down when they overheat. Secondly, anything that uses water (heavy or light) as a moderator *can't* melt down. Without a moderator, the reactor stops dead (it needs the moderator to react). With water as a moderator, your moderator disappears as soon as it heats up enough to burst pipes. End of reaction.
Lastly, the "slowpoke" style of reactor described can't have runaway heating at all. As it heats up, the core expands, pushing the fuel rods away from each other and making the reactor less efficient. Do whatever you like to it; it doesn't run away.
Trivial as it may seem, energy gained by tidal power is, erg for erg, slowing down the rotation of the Earth. True right now the results are inconsequential, but if massive projects were undertaken to supply 30% of the Earth's onging power needs with tidal forces, over the long run it could have an impact, and it's not exactly like we have a way to repair the damage by speeding up the Earth's rotation...
At least clean fission only eats up matter which, though not a renewable resource either, is constantly being replenished on the order of tons a day from micrometeorites.
Kevin Fox
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Kevin Fox
I am in need of enlightenment.
e -of-a-walnut mind takes this to mean, there are other possibilities. Does anyone know of any research being done on this? (Of course, with the fear of anything nuclear that seems to prevail in modern society, I wouldn't be surprised if a project like this would find difficulty getting funding.)
;)
Nuclear Fission releases incredibly large amounts of energy, even when it is a controlled fission such as that in a nuclear reactor. If I understand correctly, nuclear fusion is capable of releasing as much as if not more energy. But like the topic says, IANANP.
Now, perhaps I read too much science fiction, but surely there must be a better way of harnessing this energy than using it to boil water (in the case of current nuclear power stations) or heat up helium (in the case of this article) to turn a turbine to create electricity. It seems to me that a LOT of energy would be lost in the transfer from heat to mechanical to electrical energy.
The article mentions that "The early designers and builders minimized the risk of their projects by combining the new nuclear fission--based heaters with the well-proven closed-cycle steam engines." So, my Isaac-Asimov-reading-lets-build-a-reactor-the-siz
I dunno, but it seems like an awful lot of energy is being wasted in the current reactors, including these new PBMRs mentioned in the article
And I have to admit, I wouldn't mind having a personal sized one to power my home for a couple of years (decades? centuries??...depending on the amount of fuel). Oh well...perhaps I was just born a few hundred years too early.
"Empathise with stupidity, and you're halfway to thinking like an idiot." - Iain M. Banks
Nuclear fission in your basement? SAY! That is a clever idea. This is what old sub commanders think about when they retire. QUOTE: Eskom, a large public utility in South Africa, has taken a serious look at nuclear fission technology and is committed to the pre commercial development of an alternative type of machine called the pebble bed modular reactor (PBMR)..... Of course, the early adopters of such a technology will not be average homeowners. A likely initial customer might be the owner of an isolated tropical island or a remote mountain with a spectacular view. (AN IMPORTANT MARKET I'M SURE, MH) The machines could be designed as black boxes containing a decade or more of fuel and needing only a cooling supply and a place to put the output power. They would not spoil the view with an exhaust stack and could be buried to muffle all noise. (ON THE OTHER HAND, WHEN FORGOTTEN AND REDISCOVERED 200 YEARS LATER, THEY MIGHT POISON ALL LOCAL DRINKING WATER ... BUT NEVER MIND, NEVER MIND, AT LEAST THOSE ANNOYING SMOKE STACKS WON'T BOTHER THE ISLAND'S OWNER...)
The possibility of home-size cousins of the PBMR coming to a neighborhood might raise concerns. (WHAT ME WORRY?) What if an external explosion, as from a ruptured natural gas main, shattered the tough shield surrounding the PBMR and scattered the pebbles? (HOW COULD THAT HAPPEN, IN OUR MODERN SOCIETY?) In such a scenario, the radioactive material would remain contained within the pebbles. (OH DR. SCIENCE, I'M SO GLAD THE PUBLIC IS SAFE!) Of course, the pebbles would be hot, in terms of both temperature and radioactivity. (WELL... THAT DOES SOUND MILDLY WORRYING.... LITTLE HOT RADIOACTIVE PEBBLES ALL OVER THE NEIGHBORHOOD... SHOULD I WORRY?) Residents would need to be evacuated until professionals collected all the pebbles, but then they could return safely to their homes. (OH GOOD.. FOR A MOMENT I WAS WORRIED, BUT SINCE THERE WOULD BE PROFESSIONAL PEBBLE COLLECTORS INVOLVED, I'M SURE EVERYTHING WILL BE OK!!!)
END QUOTE
And there is not a single mention of nuclear waste, fission by products, or waste disposal issues!
2-3% of it will always be "in the transportation tube" rolling down local railways, interstates, and highways. And if one of these trains derails? Or truck jack-knifes?
Then the heavily-armoured barrels get their paint scuffed.
I don't trust nuclear waste barrels to last a hundred thousand years, but I do trust them to survive anything short of a point-blank strike from heavy artillery.
If you *do* fire heavy artillery at point-blank range into a nuclear waste barrel, you'll get a clould of glass shrapnel - the safest transportable form of nuclear waste puts waste oxides into glass, where they stay (glass is quite durable and resistant to chemical attack). Scrape up the first foot of soil for a quarter of a mile around, put that in barrels, and sent it to the waste dump along with everything else. No additional contamination.
In summary, I don't think that accidents during transport are a concern. I'd be more worried about deliberate theft, and the risk of that can be made no worse than it already is with waste stored at power plants.
Also, storing waste at the plants is not a viable long-term solution, as they aren't in earthquake-free regions isolated from the water table. One good disaster, and *all* of the plant's waste goes into the environment.
They don't have to be buried. Extract the plutonium and use it up in a reactor designed for it. Put the other stuff in the business end of a nuclear accelerator, or park it on the edge of a fission reactor, and make it break down sooner than by waiting for natural decay.
The problem with any scheme that involves chemical reprocessing - which used to be widespread - is that you get a lot of minor mishaps occuring, which exposes workers and the nearby environment to small amounts of Really Nasty Stuff (tm).
If I understand correctly, worker health liabilities were why plutonium reprocessing plants were abandoned, but in general, it's just plain safer to seal up the waste in very sturdy containers and drop them in the continental sheild.
As far as transmuting the waste is concerned, there are problems. If you stick waste next to a large neutron source (like a reactor), it will be transmuted. Continuously. This has the good effect of transmuting long-lived radioactive isotopes into shorter-lived ones, and the bad effect of transmuting non-radioactive decay products into radioactive isotopes. This won't magically make the waste non-radioactive (well, after a few centuries of this, it might all end up as the four stable lead isotopes, but don't hold your breath).
In summary, while burying the waste in mine shafts is an imperfect solution, it's one of the best ones that we currently have. We can always dig it up later if we find a really good way to dispose of it.
The big problem for nuclear power is that the Nuclear power industry has lied and lied and lied. It is no wonder that the public don't trust nuclear power, they would be morons if they did.
The only reason Chernobyl went up and Three Mile Island did not is luck. Both reactors were designed using inadequate computing power. Chernobyl went critical because there was a region of positive feedback in the operation cycle that was not uncovered using the two dimensional simulation techniques used in both the USSR and the US at the time.
If the west was so smart in its nuclear power strategy Three Mile Island would never have been choosen as a site with Manhattan right next door.
The problem today is that having lied about the costs, the safety and the military use of byproducts the civil nuclear industry is going to have a hard time being trusted even if it is proposing an entirely different technology.
Pebble bed and Heavy Water designs are both intrinsically safe technologies that will 'fail safe' in case of failure. Unfortunately the nuclear industry claimed that the intrinsically unstable and dangerous AGR and light water designs were 'fail safe'.
The backers of pebble bed have a point. However having been lied to the public is entirely rational in not trusting the experts again. The idiot in the Whitehouse is certainly not someone I would trust to ensure that safety standards were enforced. The administration has reneged on pledges to not drill off the coast of Florida and to implement C02 emissions caps, arsenic in drinking water is OK. And that is the crew to be trusted to regulate nuclear power?
We may need to start using Nuclear Power in the future, however I think we can wait another four years for a President who is not in the pocket of the energy companies before we let that genie out of the bottle again.
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Do people seem to forget that there is entropy in this universe? All production of electricity causes some form of energy loss. Thus the obvious problem of efficiency.
Nuclear power is very efficient, and does not pollute much. Sure, the pollutants are highly toxic, but there is a smaller proportion of it, than to coal power (as an example). I'd rather have nuclear than coal. Coal pollutes the atmosphere and is far worse than nuclear power, as is oil, and other fossil-fuel based power sources.
Water power is clean but all of the prime locations have been used... thus further plants would be on less effective/efficient sites and end up being very expensive ways of ruining the surrounding ecosystem.
Solar and wind power are not constant enough yet to be relied upon as a sole source of electricity. In addition, these technologies cannot be used universally, some locations will see a benefit while most will not be economical.
Tidal power is effective, but cannot be implemented everywhere (and I mean every oceanside town here). The local topography needs to be just right for tidal power to be economical.
Fusion power is not economical yet either, although there are projects in the works.
So that leaves us with dams and nuclear power (fission) as our clean energy sources...
The problem with nuclear power is that the public is uneducated about the safeness of the power production process. In the US and Europe, nuclear power is extremely safe because it is highly regulated. Safety measures are considered, then will be increased beyond the engineers' original specifications. Chernobyl was as bad as it was because Russia couldn't afford to build a safe plant... they followed the motto "good enough for government work."
This is for all the folks who told you fusion powers the hydrogen bomb:
The H-bomb uses a fission trigger which supplies about 10% of its energy output. The prompt gamma rays from this blast are used to compress and trigger the secondary stage; this must occur before the mechanical blast rips the secondary apart.
The secondary contains a stick of fission fuel surrounded by fusion fuel surrounded by a thick, depleted Uranium tamper. When the assembly is compressed the stick of fission fuel fissions, providing neutrons which...
Finally, the incredibly huge mass of neutrons generated by the fusion reaction induce fission in the depleted Uranium tamper, yielding about 80% of the bomb's energy. Now we have an explosion. And 90% of the energy comes from fission, not fusion.
The mantra about H-bombs being "clean" is just one of the many lies told by the nuclear industry to make itself look more useful than it really is. Richard Rhodes' books The Making of the Atomic Bomb and Dark Sun: The Making of the Hydrogen Bomb have many more details about how the current situation came about.
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