Slashdot Mirror
Amec Working on Long-Term Nuclear Waste Solution
Ckwop writes "The Daily Telegraph is reporting that Amec, the company that cleaned up Ground Zero, have developed a new process for storing nuclear waste that lasts two hundred thousand years - far longer than any radioactivity will last. The process works by mixing eighty percent soil with twenty percent waste and then heating the mixture to three thousand degrees centigrade. When the mixture cools it forms into a glass harder than concrete. While this is not the first waste process of this type it is the first to be cost effective and produces a glass much harder than previous methods. " We'll see if we still need a ten mile field of spikes I guess. A pilot facility is being built in Washington State.
After R'ing TFA, it looks like this is nothing new, just a slightly better method of vitrification. I don't know, the tone of the FA was a little, um, enthusiastic for an incremental improvement to an established method...
A house divided against itself cannot stand.
This sort of thing is done already, and often glass is packed inside a metal layer/container. Take transport: if you got fluid components, dust, or pressurised gasses, and there's an accident, the stuff spills all over the place, and into air, ground water. If it's glass, it may go in pieces, but the pieces stay were they are, with the radioactive material trapped inside.
The Vitreous State Lab at The Catholic University of America has been doing this for 30 years. Read a recent article here.
I can't seem to figure out which planet you're from, but if your homepage URL is any clue, the British cars kill just under 3,000 people every year. In case you're a yank, that figure goes up to a bit over 40,000. I'd like to see this super-duper-hyper jumbo jet of yours.
Money for nothing, pix for free
Although "harder than concrete" sounds "strong" it does not address the chief danger in long-term storage. Chemical erosion and leaching are a bigger issue than brute strength. Anyone who has ever thought about geology and objects like geodes will realize that quartz is both much harder than concrete, but also (over the long term) water soluble. The real trick is to encapsulate the waste in something that won't dissolve or allow the migration of waste isotopes in the heat, potential liquids, and long timescales of waste storage. (I'm sure hardness is somewhat of an issue when trapped alpha particles and decay products create expansion stresses in the glass)
I do think that vitrification is the way to go, but statements like these do the public no good when they mislead them on what characteristics actually make for a good containment system.
Two wrongs don't make a right, but three lefts do.
Of the top of my head... There was some discussion and research done a while back to establish what sort of symbolic warning to future generations we could use on the surface above extremely hazardous waste such as long half-life radiactive material. The idea of using a lot of large monolith type needles came up, these were supposed to be truly massive and the idea was to convey 'dont dig here', or something. It seems pretty sensible to at least try and warn future generations about an area such as a geologic waste depository but what if the warning signs get misconstrued? If we ever wipe our selves out, which is more than likely in my opinion, then would the next round of intelligent life understand what we ment? Might not such a legacy raise the same kind of curiosity that we have and lead to some archealogical dig only to get themselves zapped...
my other sig is written in brainfuck
Yes, but of course what is needed is not a package that will last until any radioactivity has disappeared, but a package that will last until the remaining radioactivity is negligible compared to the normal background radioactivity.
One of the waste products produced by nuclear reactors is Iodine-129. The half-life of I129 is 15.7 million years.
You'll have a greater risk of radiation exposure from going outside on a sunny day than from all the iodine-129 in the world. The point about keeping an eye on iodine-129 is because it's found together with the more dangerous isotopes, iodine-131 and iodine-133, which have half-lifes of 8.02 days and 21 hours respectively, making them very active and dangerous substances:
From http://www.jaeri.go.jp/english/press/2001/011017/ (Japan Atomic Energy Research Institute):
Among the radionuclides emitted during a nuclear accident, the Iodine (131I, 133I) isotopes exhibit strong radioactivity that affects the human body but they are difficult to quantify because they have short half-lives and turn quickly into stable, non-radioactive substances. On the other hand, the iodine-129 that is hardly hazardous at all due to its long half-life period is emitted at a certain ratio with respect to iodine-131 and iodine-133. The measurement of iodine-129 makes it possible to estimate the emission of radioactive substances such as iodine-131
Iodine-129 by itself is hazardous for roughly 0 seconds, 0 minutes and 0 years. So which physics course did you take again?
That's about the same amount of output as 17 modern LWRs. THe PBMR is well suited to areas without an existing electrical infrastructure. Using PBMRs to power the U.S. isn't practical and that's not what they're designed to do.
Now if you built 100 additional LWRs and double the nuclear power production in the U.S. (up to 40% from today's 20%) you'd have a massive impact on greenhouse gas emissions (We'd be able to join the Kyoto protocol) and reduce our reliance on foreign sources of natural gas. Very little oil is used for electricity generation in the U.S.
Heating the soil up that high to melt it into glass will also vaporize the lead and send it into the air.
The faster a substance decays, the more energy it emits. Conversely, substances which only decay very slowly emit very little radiation. Thus U-238, with it half-life of 4.5 billion years is far less radioactive than, say, Carbon-14 with its half-life of approximately 5,730 years. There are, of course, different types of decay, and heavier atoms tend to decay producing alpha particles and gamma rays rather than the beta particles that are common in lighter elements. Even so, elements with half-lives measured in millions of years do not typically emit enough radiation to be a threat to humans or to nature. The intensively radioactive products tend to get rid of themselves, so it is the medium intensity materials, such as the infamous Sr-90, with half-lives measured in months to millenia, that are particularly dangerous. It is also worth noting that alpha, beta and gamma rays can not make materials radioactive - it is neutrons that do that - and that alpha particles, which are the least penetrative of the three primary radiative products of nuclear decay, are also the most strongly ionising, while gamma rays, the most penetrating, are the least ionising, given the fact that they consist of mere EM radiation rather than charged particles like alpha and beta rays.
Humans are exposed to ionising radiation every day, and have been during the entirety of history. For this reason we have a variety of genetic repair mechanisms. The mere presence of ionising radiation is not a matter of concern; under normal circumstances the most significant sources of such radiation are natural. It is only when the level of radioactivity overwhelms the body's natural defenses that radioactivity becomes a threat to human health.