Uranium Pebbles May Light the Way 629
kristy_christie writes "According to Wired News, South Africa's state-run utility giant Eskom and its international partners want to build the world's first commercial 'pebble bed' reactor, which, instead of using fuel rods, 'is packed with tennis ball-size graphite "pebbles," each containing thousands of tiny uranium dioxide particles'. To developers, the Pebble Bed Modular Reactor promises a rebirth of nuclear energy. Proponents insist that the reactor's design features make it 'meltdown-proof' and 'walk-away safe'."
Sweet (Score:5, Insightful)
Nuclear Power, despite the cries of environmentalists, is possibly the cleanest mass power source. On a scale of power generated per ton of input material it is incredibly efficient (bested only by those power sources which require no nonrenewable input, like wind/tidal/etc.), generates no effluent or air pollution, and needs only a competent staff (and, unfortunately, security), to stay running properly.
Nuclear plants may be prohibitively expensive to build these days, but if "pebble bed" reactors cost significantly less, then they may lead the way back towards what I view as our ideal energy source.
It's time to give nuclear a second chance.
Re:Sweet (Score:2, Insightful)
Re:Sweet (Score:5, Informative)
There's big money in keeping things the way they are. Nuclear power is so heavily regulated that it is too expensive. Thats the only reason we don't have more of it. If the other types of plants were regulated just as strictly we'd switch over as quickly as we could build them.
Partly true... (Score:3, Insightful)
True, if you only consider what is legally released into the environment while the nuclear plant is operating. If you consider the fission byproducts and their "disposal" (e.g. long term storage) then this isn't true. Yucca Mountain nonwithstanding, the problems associated with nuclear waste may not be worth the benefit (and I'm a nuclear-trained engineer)
Re:Partly true... (Score:5, Interesting)
Also, we've done well with Reduce and Recycle, but how are we doing with Re-use? It seems to me that much rad"waste" is just a resource for which nobody has tried hard enough to find a use. Medicine, nondestructive testing, long-term preservation of organic matter, etc. all have uses for long-lasting sources of radiation. (I tell my kids to remember where the landfills are, because their grandchildren will want to mine them.)
Re:Partly true... (Score:5, Insightful)
However, use of plutonium is rather taboo for some reason -- witness the furor over Cassini's radioisotope generator, which some environmentalists claimed could kill thousands in the event of an accident on launch in 1997 or during the flyby of Earth in 1999, with one site suggesting a 10-micron particle could result in the exposure of a person inhaling it to thousands of REMs. Their argument was that the release of the 72 pounds of plutonium would be catastrophic over centuries.
An article in a 1993 Oak Ridge National Laboratories Review states, "according to NCRP Reports No. 92 and No. 95, population exposure from operation of 1000-MWe nuclear and coal-fired power plants amounts to 490 person-rem/year for coal plants and 4.8 person-rem/year for nuclear plants.
Even factoring in mining -- where radioactive dust presumably goes into the air -- and disposal -- where various bits of radioactive dust and water are released -- nuclear plants produced only about a quarter of the average radiation dosage that coal plants do over their lives. I've seen the strip mines that are used to get at uranium, and while it's not pretty, it's not nearly as bad as the destruction of entire mountains in the Appalachians. There is also research going into extracting uranium from seawater for about $120 per pound, which, although about 10 times the current rate, could be more environmentally safe and could provide thousands of years of power, presuming we operated on nuclear power for that length of time.
I'm all for nuclear energy. While I am also a proponent of renewable sources, I don't like the environmental damage caused by hydroelectric. Solar has issues of night-time electricity use, and it is reportedly a messy thing to make, with some pretty dangerous chemicals involved, not including any batteries that would be needed for cloudy days and night use. Wind has issues of reliability, and tidal generators have a range issue, not to mention that I wonder how it would affect the beaches to have thousands of them operating.
I recognize the dangers of nuclear energy. I know that it's hard to clean up, and that there are significant security risks; I'd much rather be in a room with an exposed piece of coal than an exposed piece of reactor-grade uranium. But that piece of uranium will be useful long after the ash from the coal has been carted off and buried. It will have given off no CO2 or nitrogen or sulfur oxides during its use (save whatever transportation is used for it), and less radioactivity.
In balance, I believe that nuclear reactors are a far better source of energy than anything else we have at the moment.
Re:Partly true... (Score:5, Interesting)
I don't think I'd want to carry it around as a good luck charm, though.
Re:Partly true... (Score:3, Funny)
That's because the chunk of ore will be far from pure uranium, it will contain traces of the decay products - such as polonium, radium and radon, all of which have shorter half lives (and are hence more radioactive).
Glad to hear that you're taking basic safety precautions though.
Best wishes,
Mi
Re:Partly true... (Score:5, Interesting)
By "reuse" I meant take the stuff that's no good for large-scale power reactor fuel and use it for something else. Like sterilization or probing metal castings for flaws. And if all else fails, someone else pointed out that the gunk still produces quite a bit of heat -- not enough for a commercial electric plant, but maybe enough for something that has to sit in an inaccessible place for decades without resupply.
Hydro...yeah, come to Indianapolis and ask the old-timers where Dandy Trail is. (It's at the bottom of a reservoir now, not such a fun place to go anymore.)
Stuff like solar, wind, tides, etc. can be stored as compressed air, used to extract hydrogen from water, pushed into high-performance flywheels, etc. so batteries are not necessarily needed.
Tidal generation might actually be a good thing for e.g. the barrier island systems of the North American east coast. Hmmm.
Oh, and coal mines are hard to clean up too. Ask about all the acid runoff. Ditto the mines that produce whatever materials go into your favorite alternative energy source.
We could boil all this down pretty compactly: energy production is messy and dangerous. So's millions dying of cold or fighting the wolves off with sharp sticks, though.
Re:Partly true... (Score:3, Interesting)
A nuke plant produces about 6.5 ounces of waste per minute, or about 20 tons per year for a typical thousand megawatt plant. A single coal plant produces about 10 tons of waste per minute, or about 300,000 tons of waste per year. Since the radioactives don't burn, they get concentrated in the ash. That thousand-megawatt coal plant releases about 20 tons of uranium and thorium (alone) from the 4 million tons of coal it burns.
All waste is an "emission", whether it literally goes up in sm
Re:Sweet (Score:5, Insightful)
'most people' don't know even the basics of how the energy is generated, all they know is that the place can explode and then there's going to be 3eyed fishes. the problem is that even if it's a 'failsafe'(won't explode) plant there's going to be hell explaining it to the people who are against nuclear power for mainly emonational reasons(and assume that people defend nuclear power for similar reasons because they hate the environment or something silly like that, or just for pure greed).
it's like that old joke... "what we need nuclear power for? i only need electricity"(dunno how the variation goes in english actually, but you get the idea).
around here there's a need for another reactor(industry needs the juice) but there's quite many people who are against it, yet they don't complain when we need to buy the same amount of electricity from russia(that is generated by nuclear reactor there, just over the border, at lower safety standards than what would be in place if the reactor were on our side of the border).
Chernobyl was stupid (Score:5, Insightful)
The reactor increased in efficiency as temperature increased. This is a nice little feedback loop. Most reactors lose efficiency as temperature increases, meaning that it is difficult to try and overload the reactor, even on purpose.
The reactor was designed to be cheap, and it did not have a dome. Domes contain radioactive material very well. Tests have shown that an aircraft hitting a dome would hardly scratch it.
As another cost-cutting measure, the reactor didn't have any good backup power. It may seem silly to have a power plant that needs power, but nuclear power plants do need power to start up and in case of emergencies. Western plants have batteries and generators.
As if these technological blunders weren't enough, some bonehead transfered control of the power plants from the ministry that designed and built them, where all the trained personnel are employed, to the ministry of energy. There are reports of operators sitting on the control board and people showing up to work drunk.
Basically, in 1986, the Chernobyl reactor demonstrated a bunch of "don'ts" to a world that should have already known.
There will always be technology out there that can be misused. The amount of that technology will only increase. Do we ban knives because people get stabbed? Do we ban nuclear power because a couple of Russians cut costs?
The 'ball' nuclear reactors are basically foolproof. You put a bunch of balls next to each other and you get heat. This is not weapons grade Uranium.
I only see one problem with nuclear -- the small amount of waste that is generated needs to be handled properly. It can be done, but it just has to be done right.
Re:Chernobyl was stupid (Score:3, Interesting)
The press is essential to things like safety. In the UK, someone blew the whistle on results being falsified at Sellafield. BNFL immediately sacked 5 staff.
Let's say hypothetically BNFL hadn't, and just decided to cover it up, and then the press had found out about it - the uproar against the power industry would have been massive. Then, if government did nothing that would have damaged them.
The totalitarian equivalent is - nuclea
Re:Chernobyl was stupid (Score:3, Informative)
Don't forget about the one at the Tokaimura fuel processing plant in Japan in 1999. It was an inadvertent criticality in which two workers were killed by radiation exposure and dose rates in the surrounding area were significantly elevated. As usual for nuclear accidents, it involved a lot of gross stupidit
Re:Chernobyl was stupid (Score:3, Funny)
Philistine.
Compare this against Three Mile Island. (Score:3, Informative)
Since Chernobyl had NO containment structure, when that reactor's fissile material pile exploded there was NOTHING to stop its release into the atmosphere.
Just for your info (Score:3, Informative)
Re:Chernobyl was stupid (Score:3, Insightful)
Yeah, I mean who really needs to travel by plane anyway? While we're at it, lets do away with recreational cruise ships, all military aircraft, naval vessels, missle silos, etc.
P.S. - if you want to debate the need for military equipment please start a new thread, they were just examples of things "that might kill thousands of people while handled by a drunk."
Re:Chernobyl was stupid (Score:3, Informative)
The Lessons of Chernobyl (Score:5, Interesting)
the problem that most people have with nuclear power is tchernobyl(or similar catastrophy that would release radioactivity to a wide area).
I'm glad you mentioned Chernobyl...
'is packed with tennis ball-size graphite "pebbles," each containing thousands of tiny uranium dioxide particles'... Proponents insist that the reactor's design features make it 'meltdown-proof' and 'walk-away safe'."... because apparently these people haven't learned anything from it.
The most important lesson of Chernobyl is that graphite burns. So if you lose control of this thing, it will catch fire. And the fire will spread radioactive decay daughters all over the place.
I am a big proponent of nuclear power, but only of one design: CANDU (CANadian Deuterium-Uranium). It's inherently impossible for it to melt down. It uses U-238 (natural uranium, in the form of "ceramic" pellets of uranium dioxide) which is NOT capable of a chain reaction without a heavy water moderator. (Heavy water is just water where the hydrogens have neutrons. Non-radioactive, naturally occurring, and just slightly heavier than normal water.)
As a result, if you lose control of a CANDU reactor, the reactor will overheat. Pressure will build up in the heavy water system until something breaks. The moderator will escape as steam, and since the fuel is essentially non-water soluble, with only extraordinarily small trace amounts of radioactive materials. With no moderator, the chain reaction stops, and the reactor cools down. This process occurs as a result of the laws of physics; in other words, Chernobyl cannot happen at Pickering or Darlington even if all the control systems fail or someone goes to extraordinary lengths to circumvent them.
The other great lesson is not to let boobs run the reactor. All nuclear power programs have had problems with this in the past; a "walk away" approach simply encourages this.
Re:The Lessons of Chernobyl (Score:5, Informative)
Re:The Lessons of Chernobyl (Score:3, Informative)
Each pebble is a sphere.
A large number of spheres are arranged in a pile.
The density of the uranium is a function of the radius of the spheres.
Like most things, the pebbles expand as they get hot.
In turn, this creates a negative feedback loop which should prevent a catostrophic failure.
Re:Sweet (Score:2, Insightful)
Is it? Last time I checked, they still used the cyrillic alphabet in Ukraine. Yes, "Ch" is the dominant convention in the English speaking world, but that doesnt mean its the only one.
Re:Rational thinking. (Score:5, Informative)
I don't know if that is the case... Coal, the major alternative to nuclear, has numerous carcinogens among it's combustion byproducts. These carcinogens are not tightly controled like the nuclear ones are, they are simply dumped into the environment surrounding the plant. I would much rather have a nuke in my back yard, than a coal burner...
Re:Sweet (Score:5, Informative)
We don't know who's going to be blowing who up even this time next year.
Very little of the waste produced by power plants has this sort of a half life. Even so, the less radioactive a substance, the longer the half-life. Those elements that do lasts tens of thousands of years simply aren't producing that much radiation.
Highly radioactive substances, on the other hand, have shorter half lives, and aren't much of a worry after a few decades.
-josh
Re:Sweet (Score:2, Informative)
Re:Sweet (Score:3, Interesting)
There is a 30-turbine site proposed on the Isle of Skye. Each turbine will produce 10MW of electricity, and they are *huge*. Furthermore, the bases for each pylon will require 400 cubic metres of concrete - 2800 tonnes. Making this concrete will release 2800 tonnes of CO2 into the atmosphere - and th
Re:Sweet (Score:5, Insightful)
What metric are you using to say that nuclear power has historically been unsafe? The number of deaths caused per MWh produced? Deaths or injuries per reactor-hour of operation? Average deaths per year at a given plant?
Really, compare these metrics to that of any other power distribution plant and you will see historically, even with the huge publicized disasters like Chernobyl and TMI, that no other large scale power producer even compares in safety to nuclear power.
But since we're on the topic of nuclear power safety history, the website The History of Nuclear Power Safety [owt.com] is an excellent resource.
Re:Sweet (Score:5, Insightful)
Two words: Lung Cancer.
That is the alternative, and pollution from traditional power generation plants is killing people every day, and sickening many more.
There is not a single permanent disposal site world-wide. no one can guarantee the safety. the U.S. government even has a website on _just this problem_. Ready-made dirty bombs are driven in trucks all over the country. GREAT IDEA.
If someone wants to kill a lot of civilians, all they need is a garage lab to produce chemical or bio agents. Much more effective, much easier to deal with, even more scary (1 gram of the right bio agent could kill millions). See the recent research on mouse pox [i-sis.org.uk] for some really scary stuff (did that story make /.?). How 'bout a bio agent that'll only wipe out one ethnic group? The research is just about there. It is always hard to evaluate relative risk, but to me nuke power is way down the list.
BTW, as far as nuke disposal, there's a good reason for a lunar colony... =) Name another major energy source where the pollution could realistically be taken entirely off-planet.
Also BTW, I hope some of the recent solar energy developments lead (finally) to competitive photovoltaic power generation on a distributed basis (that'll tick off the power companies!). One of the more exciting developments is solar fabric [si.edu], which can be used in curved building designs.
Re:Decomissioning and waste management? (Score:3, Insightful)
Yeah, disposal is a problem.. but it's not like it wasn't just lying around to begin with.
Oh please.. that old, tired argument again. YES, uranium occurs in most rocks in concentrations of 2 to 4 parts per million and is as common in the earth's crust as tin, tungsten and molybdenum. HOWEVER, uranium in the natural state is a mix of two isotopes; 99.3% U-238 and 0.7% U-235. And guess what? U-238 is barely radioactive, with a halflife of about 4500 million years. U-235 on the other hand is way more radi
Re:Decomissioning and waste management? (Score:5, Insightful)
Sure, we "enrich" the uranium-- largely by sorting isotopes. There's no reason why you couldn't choose to de-enrich/deplete the uranium back down for storage, if you thought this was beneficial. This is why it's entombed in glass in many storage proposals, and why it's often reprocessed-- so you can sort the "useful fuel to reuse" and "spent fuel/waste".
There are intermediate-term (80-500 year) storage problems involved with the high level wastes produced in fission reactors. The thing is, these wastes inherently have short half lives and decay to more harmless stuff very quickly.
Re:Decomissioning and waste management? (Score:5, Insightful)
Fact: Spent fuelrods from reactors are a major enviromental problem.
Fact: The byproducts of all other currently viable forms of energy production are major environmental problems.
I can't think of anyone who would say that nuclear waste is not bad. But I for one, and many others who have researched the topic, believe it is less bad than the alternatives.
I would rather have a small amount of really bad stuff being controled, than a huge amount of pretty bad stuff being spewed into the air I breath every day.
Half-errors on half-lives in parent post (Score:5, Informative)
Not true. The half-life of U-235 is 710 million years -- enriched uranium is NOT too hot to handle.
Pu-239 (half-life 24400 years) and Pu-240 (half-life 6580 years) are hotter and are the reason spent fuel needs to be sequestered for so long. But the really nasty, ultra-hot radioisotopes are all the neutron-rich fission byproducts from splitting U-235 or Pu-239. Byproducts like barium-140, cesium-134, cesium-137, and iodine-131 have half-lives in the days to only a few years that make them intensely radioactive (thousands of times more radioactive than Plutonium and millions of times more radioative than U-235). Worse, these byproduct elements will chemically react with ordinary matter, form water-soluable compounds, and lodge in living tissue if injested.
Fact: Spent fuelrods from reactors are a major enviromental problem.
Extremely true, but not because of U-235.
Re:Half-errors on half-lives in parent post (Score:5, Informative)
Byproducts like barium-140, cesium-134, cesium-137, and iodine-131 have half-lives in the days to only a few years
AFAICR, a short lifetime is actually a good thing when considering
environmental concerns: with a HL of, say, 10 days, in less than a year
there'll be practically nothing to worry about.
It's the mid-range isotopes that are problematic.
Re:Sweet (Score:3, Informative)
Re:Sweet (Score:5, Insightful)
That is a myth spread by the anti-nuclear lobby, who are really anti-industry, as a side-effect of being anti-capitalist. Think about it logically for a minute. Why is spent fuel dangerous? Because it emits radiation. What is radiation? It is energy. What is the point of any fuel? That you can extract energy from it.
The problem of what to do with nuclear waste has already been solved: just loaded it into another type of reactor (called a "fast breeder reactor") and continue to use it. Nuclear waste simply is not a significant reason not to use nuclear power. The only problem is what to do with old, worn-out reactors.
Re:Sweet (Score:3, Insightful)
Truth is that Wind power is a hard paying proposition - cheap energy, doable today, without all the headaches that comewith nuclear.. In what sense is that "anti-capitalist"?
Re:Sweet (Score:3, Interesting)
The biggest argument is cost - these plants are proving very expensive to decommission, and the waste expensive to dispose of adequately. In the UK, its the poor taxpayer who is being left with this bill from the first generation of plants..
The biggest arguments against Nucle
Re:Sweet (Score:5, Informative)
1)It was just post TMI
and
2)To do them right, you end up with NEAR weapons grade PU in the reactor and in the reproccessing plants. He thought there was too much of a security risk to have this much PU running around
A LOT of the initial assumptions on the cost of Nukes had to do with the fuel being reprocessed - aka, make your waste into fuel again - what is left is low level stuff - LONG half life, but also low radiation
One of the huge problems we have with storage is we keep trying to store "Mixed" waste - It's got high level waste (say, PU) mixed with low level waste.
Re:Sweet (Score:4, Interesting)
And generate all sorts of weapons-gradd material in the process. It's a major proliferation risk; that's why the U.S. has not chosen that option.
Nuclear waste simply is not a significant reason not to use nuclear power. The only problem is what to do with old, worn-out reactors.
There's another little reason: the risk of terrorist attacks on the plants. People argue all day about the technical safety and waste disposal issues. However, the security issues of proliferation and terrorist risks are by themselves enough to make avoiding nuclear power a no-brainer.
Our president has been running around hysterically shouting about WMDs for several years now. What's one of the most significant sources of material WMDs? It's when 2-bit countries convince people to let them have their own nuclear reactors. Again and again, we find out that they start producing weapons materials as soon as they crank up their plants. Part of the "war on terrorism" should be developing energy sources that allow us to totally eliminate nuclear power with its fuel cycle that has allowed several countries to hide their nuclear arms programs. Not to mention the problem that nuclear plants in your own country allow someone to turn a truck bomb or an airplane into a WMD (and don't bother bringing about the 3-foot thick shield around the reactor; I'm talking about attacking the unshielded spent fuel storage ponds).
Meltdown isn't the (whole) problem (Score:4, Insightful)
That said, I'm not against nuclear power (from fusion) per se. Of the options we have, it's one of the best at the moment. "Alternative" power sources need a lot more work, and fusion, whilst extrememly promising, just isn't practicable yet (unless I've missed a major breakthrough in the last couple of years). I'm just pointing out that there are still other problems that need to be addressed.
Re:Meltdown isn't the (whole) problem (Score:5, Insightful)
That way you dont get a lot of waste, and you get many many times more use out of the fuel you have.
Nuclear waste is a problem that already has a solution, and a solution that is ecologically sound and very much in line with recycling and reuse.
Re:Meltdown isn't the (whole) problem (Score:2, Interesting)
Re:Meltdown isn't the (whole) problem (Score:5, Interesting)
Maybe it's time to reconsider those bans, as it is becoming quite apparent that there is no near term solution to the energy problem apart from nuclear energy and there is no other good way to handle nuclear waste.
Re:Meltdown isn't the (whole) problem (Score:3, Interesting)
I would be very surprised if this is true, care to provide some links? I have had dealings with BNFL - British Nuclear Fuels Limited. They carry out this reprocessing of spent Uraniaum on facilities less than 50 miles from where my parents lived all their lives.
Re:Meltdown isn't the (whole) problem (Score:2)
That's the main problem with nuclear energy, not that it is not technically sound, the problem is that people are much too inclined to ignore engineers and cut corners. Especially for profit.
I would like to see more research into accellerator based fusion. The
Re:Meltdown isn't the (whole) problem (Score:3, Interesting)
a) it's quite messy, dangerous and difficult to do safely. Not impossible, but neither easy nor cheap.
b) You turn a lot of moderately radioactive waste into a smaller amount of highly radioactive waste (purified fission products) and some reusable fuel (some of which is plutonium, which raises certain accounting and security issues) and in the process create a whole lot of medium level waste (irradiated machinery and such).
Neither is insuperable, but recycling is not
Waste is less of a problem in this setup too (Score:3, Informative)
It would seem, critically, that the waste can be stored on site for 40 years, does not need to be transported elsewhere, and is inherently more stable than the waste in a typical water reactor.
Re:Meltdown isn't the (whole) problem (Score:5, Informative)
Re:Meltdown isn't the (whole) problem (Score:3, Informative)
Re:Meltdown isn't the (whole) problem (Score:3, Insightful)
I think you are. While stable on human lifetimes, concrete is not, I believe, stable on the necessary time perios. It is also water permeable on a long enough timescale. In the past, people were researching "glassification" - incorporating the wast into a kind of glass which is much more stable than concrete. Even then, I believe they found that the heat generates by radioactive decay i
Re:Meltdown isn't the (whole) problem (Score:4, Interesting)
burying it deep in some stable part of the earth is the best way currently though(at least much better than the sometimes used method of just stacking it in a shack). and besides, ancient egyptians got their cursed tombs, WHY CAN'T WE HAVE THEM??!?!?-)
however, we have much bigger waste problems than just nuclear waste.
Re: Meltdown isn't the (whole) problem (Score:2)
> burying it deep in some stable part of the earth is the best way currently though(at least much better than the sometimes used method of just stacking it in a shack). and besides, ancient egyptians got their cursed tombs, WHY CAN'T WE HAVE THEM??!?!?-)
One line of thinking is that when word goes around that the site is cursed, people will conclude that the curse must be guarding a buried treasure and the chances of a dig goes up instead of down.
(Hmmm... maybe all those Egyptologists died of radiatio
I'm a proponent of nuclear energy (Score:3, Insightful)
Many of the world's problems exist because of the small patch of oil-soaked land out in the Middle East and the lack of trustworthy stewards of those fields. With Gulf War II over and those oil fields finally in the hands of Western democracies we may see some improvement in global stability vis a vis the opening of OPEC to its main customers. However, because we continue to rely on oil as our primary power source we will likely continue to have problems as the oil fields run drier and drier.
It is good to see Africa (of all nations!) take the lead in this new system of nuclear power generation. Older systems like the ones in Canada and France are fine, however it would be a stretch to say that they are perfect. There is plenty of room for improvement in those power plants. This usage of uranium pebbles is one such improvement, but there are more.
It is a problem that people would be willing to block the development of Africa because they object to the usage of these newer power systems. Especially so because for the most part the same protesters unwittingly reap the benefits of their own country's nuclear power generation systems.
Re:I'm a proponent of nuclear energy (Score:3, Insightful)
Global instability over the past, oh... how about all of recorded history, has been about power struggles (that usually have very little to do with oil). Imperialism, world wars, revolutions, slave revolts, coups, violent protests, terrorism - all these examples of instability are caused by struggles for power (freedom being a power). Oil may seem like the cau
Re:I'm a proponent of nuclear energy (Score:2)
At the risk of redundancy, Africa is not a nation. The article poster meant to say "South Africa", which is.
Waste disposal (Score:4, Insightful)
They claim the graphite and silicon carbide around the pebbles will keep it sealed for ~ 1 million years, which is impressive. It'll be interesting to see if humanity is around in ~1 million years
It also produces about 19 tons of radioactive waste (in the form of these coated pebbles) every year. That's going to be some landfill site, if the technology takes off...
Simon.
Re:Waste disposal (Score:5, Informative)
I remember seeing a demo of this stuff in school.. It's so safe to use in a reactor it's crazy; they referred to it as "walk-away" safe. Lose _all_ cooling in the core, leave it over the weekend, fix it on Monday. It was going to bring about a revolution in safety WRT nuclear power generation. It's nice to see this finally coming to fruition.
Re:Waste disposal (Score:3, Interesting)
The key error in this thinking is the assumption that the site has to be stable.
I propose a deep sea trench, like the Marianas.
1) The depth of the trench will provide more security than can ever be achieved on land, given the pressures of miles of ocean water.
2) The waste will have to be packaged in non-water-soluable form. These ceramic pebbles seem to be just the thing.
3) Any waste rel
Re:Waste disposal (Score:2)
There are differences between landfill sites for domestic waste, and those for nuclear waste, with there being significantly less choice in the nuclear sites...
Simon
Re:Waste disposal (Score:2)
Do you really want to drop nuclear waste (ie: the most dangerous thing we've ever manufactured, modulo the safety claims) into an unknown environment ?
Before we potentially cause catastrophic harm to an environment, perhaps we should know something about it first ?
There are lots of ways to get rid of nuclear waste. Every one I've come across has serious drawbacks, mainly due to the nature of the was
-1 Flamebait (Score:4, Insightful)
Africa? A continent not a country (Score:3, Informative)
Africa is not a state or a single country for that matter, it's a continent made up of many states. Please be specific, ppl are very ignorant about this, just like many think that all africans speak the same langauge (there are over 200 langauges in Nigeria alone for example).
Re:Africa? A continent not a country (Score:2)
It should be high-school knowledge that culturally and genetically, there is more variation in Africa than in the entire rest of the world, by a huge factor. It's easy just to lump this huge, seething continent together into an amorphous lump, but it's very far from the truth, which is that even a small part of a country like Nigeria has measurably more human variety than anything we're used to.
Ehrojue, bioju
I hate ignorance! (Score:5, Informative)
I'm going to pop a vein! Afirca is not a country, it's a continent [reference.com] . South Africa, the country where Eskom resides, is a country in Africa (easily confused with South America by Americans. South America is a continent south of North America, the continent with three different countries on it, including the USA). There are 54 independent, different countries in Africa, each with their own government. Africa is not simply a big ol' jungle where everyone speaks Swahili (only 50 million of the more than 700 million people in Africa speak Swahili).
OK, now that I got that off my chest: Eskom has been talking about this for a while now, and they are facing some resistance to the idea. The problem being the general conception that "nuclear is evil".
Re:I hate ignorance! (Score:3, Insightful)
South Africa, the country where Eskom resides, is a country in Africa (easily confused with South America by Americans. South America is a continent south of North America, the continent with three different countries on it, including the USA).
Er, so it isn't ignorant to confuse a Slashdot story poster with "Americans"?
I've never confused South America with South Africa, nor has anybody I know.
Re:I hate ignorance! (but not enough to avoid it) (Score:3, Insightful)
When you're done correcting the original poster's grotesque ignorance of geography, you might spend a little time correcting your own. There are ten nations on the North American continent. The seven you forgot are: Belize, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama.
Environment/North Korea (Score:5, Interesting)
though many popular activists site environmental reasons as opposition to nuclear energy, disposing of nuclear waste really isn't that difficult. Most scientists (at least those in the field) object to nuclear power because of the potential of the spread and proliferation of weapons. while environmental issues ARE a concern (there's always some governmental dweeb that screws things up), it is something that can fairly easily be isolated given the proper precautions. Part of the reason that these reactors get so much attention is that these same experts have much fewer qualms with them precisely because they are so much more difficult to make weapons-grade uranium/plutonium from. (i cite Howard Margolis, Dealing with Risk as a decent summary of this topic).
Re:Environment/North Korea (Score:3, Insightful)
Landfill or that Mountain Place? What if it seeps? Breaks/chips/breaksdown and leeches into the soil substrate? Three eye fish, as cool as they are, will not be the worst of our concerns.
Re:Environment/North Korea (Score:4, Interesting)
Africa isn't a state (Score:4, Informative)
South Africa is a country. It's at the tip of Africa. You'll never guess where it is in Africa.
It was a British Colony, but gained independence about 55 or so years ago, and promptly began to institutionalise pernicious racially-based discrimination. It was called Apartheid. After a long struggle (40 years) the white people agreed to share power and democratic elections took place. Nelson Mandela (you may have heard of him) was elected president.
The economy of South Africa is split - there's a strong first world component, and a large third world component. The first world component rivals the economies of Europe and the USA in sophistication - though it's much smaller. The third world component - i.e. subsistence farming, and subsistence trading - involves many more people. Unemployment rate is high - a few years ago it was 40%. Not sure what it is now. HIV/Aids rate is probably the highest in the world - hitting around 10% of population. Some places have rates as high as 40%. The current government until recently has ignored the problem.
Eskom is a world-class power utility. They have existing nuclear reactors, which were learning grounds for the Apartheid state in their quest for nuclear weapons. (Ten or so years ago South Africa admitted that they had nukes, and then destroyed them. Thank you Nelson Mandela and South Africa for making the world a safer place.)
It's questionable whether South Africa needs more nuclear power plants but Eskom has traditionally had a strong technocratic streak. (I was an employee a long time ago.) SA is rich in coal and natural gas.
I personally think that the money could be better spent given South Africa's problems - the only justification would be to export the technology. And maybe greater access to nuclear expertise is not what the world needs.
Jeff Veit
Re:Africa isn't a state (Score:2, Informative)
http://www.globalsecurity.org/wmd/world/rsa/mis
Ever heard of Hamm-Uentrop? No? Read this... (Score:3, Informative)
Re:Ever heard of Hamm-Uentrop? No? Read this... (Score:2)
And it is possible that it has improved in that time.
Re:Ever heard of Hamm-Uentrop? No? Read this... (Score:4, Insightful)
Re:Ever heard of Hamm-Uentrop? No? Read this... (Score:5, Informative)
The basis for this technology has been around for at least 30 years, as you would know if you read the background [pbmr.com] on the site. The PBMR is not the same technology as the AVR or THTR at Hamm-Uentrop.
The THTR reactor was not closed due to technical problems. The problems it experienced were related to the loading of fuel, an issue addressed by the PBMR. Even Greenpeace admits regarding the THTR "In 1989 the reactor was permanently closed due to both economic and political reasons."
Whenever the issue of pebble-bed reactors has been discussed there has been allusion to "problems" in all reactors produced so far (in Germany, Japan and the US) -- without indicating that none of these reactors have been closed down for safety reasons! The biggest problem with these reactors so far has been getting them to reliably and economically perform their purpose.
As for information exchange so that South Africans know whats getting build "in their back yard" - we have a strong anti-nuclear lobby already. Unfortunately we also live in a country where 16% of the populate are illiterate and only 25% have completed secondary education -- so just how do you think it is possible for the public to make an educated decision on how long our coal reserves are going to last, whether a particular incarnation of nuclear technology is better or worse than pumping out greenhouse gasses, and what our electricity requirements are going to be in 2010?
Come on, its ancient... (Score:3, Informative)
Building started 1970, reaction started 1983, shut down 1988, disassembling started 1991.
Its output was 308MWe, so I assume it was not just a toy.
AFAIK they had problems with the moderation and breaking of the balls.
Nothin' new, actually.
I want this technology for my car (Score:3, Funny)
Oh sure, what happens if I get into an accident? Well, that's why you build the reactor compartment the same way as an airplane's black box, if that can survive a plane crash, a car crash should be a walk in the park.
There's a problem with terroists getting uranium and making dirty bombs you say? Not a problem either! Just outlaw radiation suits so anyone that opens the reactor is instantly nuked like a frozen chicken pot pie. Of course, that means no more tinkering with your car, but would you really miss it if you never had to buy gas again?
I want my nuclear car, damnit.
Re:I want this technology for my car (Score:3, Funny)
Been there, buil that, dircarded it (Score:3, Informative)
The rationale was that it would be vatsly more efficient. In practice, those "balls" were harder to control than the normal rods. In testruns they would jam as they were processed in the facility.
So it's neither the first time this is being built, nor is it the answer to all energy-questions in the world.
Where to get Uranium pebbles... (Score:2, Funny)
Just go here [iop.org].
Uranium Pebbles (Score:3, Funny)
The Three Real Issues (Score:5, Informative)
* Proliferation of WMD. Widespread use of nuclear power creates huge opportunites for people to get their hands on fissile material or highly radioactive material. A "dirty bomb" consisting of a few hundred pounds of waste and a few hundred pounds of explosives could do incalcuable damage. Nuclear power and nuclear weapons are NOT high tech. It's technology from the era of propeller airplanes, black and white movies, radio and vaccum tube electronics.
* Economics: widespread use of nuclear power would render a large sector of the global economy useless. There is a substantial interest in keeping the world dependent on our dwindling supplies of fossil fuel -- remember suply and demand? What happens when the supply decreases and demand increases? Many nations, corporations, and ultimately individuals stand to get very, very rich by monopolizing the resource (OPEC is a benign example compared to what we'll see in the future)
* Finally, there is a more practical issue: much of today's power challenges are demand side issues. Most people are blissfully unaware of what it takes to supply a couple of killowatt hours to their homes and especially businesses.
meltdown proof??? possibly, but NOT fireproof... (Score:3, Interesting)
Sorry, but I have no faith in any process which combines a combustible material run at high temperatures and relying on keeping air out...
Let the Navy do it... (Score:5, Interesting)
They already buy power from one another on a regular basis and the more importantly the track record of the U.S. Navy in Nuclear Power useage is impeccable. The training program, security, design protocols, safety record and tradition of excellence make them the only people in the world I would trust 100% to run a nuclear power plant.
Fires? (Score:5, Interesting)
Another problem with pebble-beds is that they use natural or low-enriched uranium in a cycle where the fuel passes through the reactor relatively quickly and continuously (no big refueling outages). This makes them ideal Plutonium factories, which is obviously a matter of concern. Most of the graphite-moderated reactors ever built were designed primarily to produce Plutonium, including the Soviet RBMK's and the piles at Sellafield.
Don't get me wrong - I'm all for nuclear power for many reasons, but I'm not sure the pebble bed is that much of a breakthrough, and I don't think graphite is the best choice of material. And any operator of a plant in trouble that went home for the weekend should be shot. "Walk-away safe" my ass.
Xtra useage (Score:3, Informative)
Perhaps a better way is for us to spend money on high thermal storage with salts. Ideally, we would do small units and spread them out to provide emergency power in local areas (think hospitals, anywhere on the coast esp, Florida, Texas, and California).
The economics don't make sense (Score:4, Informative)
The latest cost estimates for building a 'demo model' is about R10 billion, and will be completed in 2008. That's about 5 years over schedule, if my memory serves me. The PBMR company ltd., not Eskom directly, is building this thing. That company's shareholders are currently Eskom and BNFL. Since BNFL is currently being restructured, as the cleanup costs for Sellafield have forced it into bankruptcy, Eskom is the only real player. (US company Exelon was involved, but now they've pulled out)
R10 billion is way more than Eskom can afford. Therefore they are looking for external partners to invest in the project, and that depends on selling PBMRs being commercially viable. Now, nuclear electricity is very expensive - one of the reasons that the world nuclear industry is in the doldrums. There was a paper in the South African Journal of Science about this some time back, which examined the economic models Eskom was using for PBMR, and found them to be wildly optimistic.
So if the economics are so screwy, why is Eskom pursuing this project? No one really knows, but I'm sure the fact that the chairperson of Eskom, Reuel Khoza, effectively controls one of the main contractors (IST), through a holding company has got something to do with it. Even if the PBMR project fails, Khoza and buddies will end up much richer. IST got handed a R260 million (?) contract, which is about as much as its previous annual turnover. Their shareprice went through the roof, making Khoza and co's share options worth a lot more.
Besides the Reuel Khoza link, there is an argument to be made that difficult-to-manage technologies like PBMR will be an incentive for the government to keep a much more centralised and powerful Eskom around for much longer. Eskom is currently facing deregulation and restructuring, and this Apartheid-legacy parastatal needs to justify why it still needs to exist. Experience in other companies has shown that deregulating nuclear power is very hard, so PBMR might be a bargaining chip in the complicated game around Eskom's future.
Funnily enough, the Wired article and the Slashdot responses have all the hallmarks of engineers - in love with 'sexy technology' while pretty much ignoring the bigger political/economic picture.
Peter
Go nukes! (Score:3, Interesting)
I *would* like to suggest that, in a setting with such grave consequences for error, engineers tell themselves daily that "meltdown-proof" really means "all failure modes are unknown." I think that would lead to a healthier attitued toward the whole thing.
Sounds like rice to me (Score:4, Funny)
"This turbine forms part of the High-pressure Turbo...Next, the helium flows through the Low-pressure Turbine, which is part of the Low-pressure Turbo Unit...The helium is then cooled in the inter-cooler. "
In other words: they're going to build a twin-turbo nuclear reactor with an intercooler.
I didn't see any mention of chrome exhaust tips, cupholders, cruise control or racing stripes, but how far behind can these things possibly be? That's gonna be one decked out nuclear reactor...I wonder what kind of stereo system they'll put into it?
Perhaps for the opening ceremony I'll fly to Africa and plant a "Type R" decal on the side of the reactor building.
Sadly, you got your facts all wrong... (Score:3, Informative)
First of all, as was already said, the waste produced by fission plants is _not_ depleted uranium. It's not like "new batteries" and "used batteries", you know. When a uranium nucleus splits, it splits into much smaller nuclei. Ones which aren't uranium at all.
Second, I get this feeling that you don't understand how depleted uranium weaponry even works. I keep reading all sorts of SF (read: stupid) posts about how it explodes inside the t
Re:Sadly, you got your facts all wrong... (Score:3, Informative)
More info:
http://www.guardian.co.uk/print/0,3858,401 9 520-107 286,00.html
Some spin:
http://www.heritage.org/Research/NationalSe curity/ EM721.cfm
Quote: "FACT: The health risks posed by the military's use of depleted uranium are extremely low."
Such bullshit. He already admits "Like lead, depleted uranium is a heavy metal that can be toxic if it enters the body". Breathe in some DU dust (should be plenty around after that pyrophoric th
Re:Clean nuclear power (Score:2, Insightful)
The difference, of course, is that you're breathing in the radioactive depleted uranium dust. Radioactivitiy is much more dangerous inside your body. Human skin pretty much blocks weak alpha radiation, but such an emitter in lungs is highly dangerous.
Re:Clean nuclear power (Score:2)
That follows only if you assume the only possbible health risk from depeleted uranium is from the radiation. It's also a heavy metal, and these are notoriusly good for health. Not.
There's also another way in which they differ. Why not blow up your glow-in-the-
Re:Clean nuclear power (Score:2)
Re:A good idea! (Score:2)
The reactor is not a traditional core moderated by graphite control rods - it's an enclosed High Temperature module which simply heats up inert helium as it passes through. The graphite walls just reflect the neutrons and insulate the module. The entire design of the reactor means that it dissipates heat faster than it is generate
Re:Money (Score:2)
Re:Money (Score:2)
RTFA. The whole point of Pebble Bed Modular Reactors is that they are smal and well, modular. You can deploy several small ones, each near where they are needed.
Re:Money (Score:3, Informative)
No thay don't. This article is about a company in South Africa, which is nowhere near the Sahara Desert. It's a bit like responding to an article on Canada by mentioning the desert in Mexico because hey, both are in North America.
Re:So what not a modern design like IFR/ALMR/AFR? (Score:4, Insightful)
Safe designs for nuclear reactors actually kind of excite me, because we clearly need to get away from fossil fuel energy.
Although, ultimately, I'm most excited about bio-mass energy (if it can ever be made to be practical at a large scale), because while burning bio-mass derivative fuels produces CO2 - at least the next generation of fuel will re-fixate that CO2 as it grows. . . it's a stable system where we are at least not increasing the amount of CO2.