208. URANIUM FROM SEAWATER (PART 2)
Continuing from the previous article (#207)...
Quantoken brought up some issues about U238 and U235, so first let's get clear on that point. These are the facts:
- Natural uranium (yellow cake) is made up of 99.3% U238, and 0.7% U235, and only the latter is directly fissionable. So quantoken is right that a kilogram of uranium harvested from the sea contains only about 7 grams of U235, which is the actual fuel in a conventional reactor.
- Reactor fuel is comprised of 3-5% U235.
- The following illustration shows what 25 tons of reactor fuel (3-5% U235) can do (click to enlarge):
- "One ton of natural uranium can produce more than 40 million kilowatt-hours of electricity. This is equivalent to burning 16,000 tons of coal or 80,000 barrels of oil." Source
More detail on the economics is provided by a Russian website, which has an English translation of a technical report by the JAERI group. This report gives a detailed cost analysis for a system capable of meeting one-tenth of Japan's electrical power needs, and concludes:
The recovery cost was estimated to be 5-10 times of that from mining uranium. More than 80% of the total cost was occupied by the cost for marine equipment for mooring the adsorbents in seawater, which is owning to a weight of metal cage for adsorbents. Thus, the cost can be reduced to half by the reduction of the equipment weight to 1/4.So high costs come from an unexpected direction: construction of mooring. The paper describes the issues:
Each of the recovery systems investigated here is based upon using a layered adsorbent in the form of polymeric nonwoven and mooring in seawater after insertion of such adsorbent into a stainless steel cage. As a result, about 80% of cost is for mooring even though costs very according to the mooring method. This is due to construction spending for mooring the large mass of adsorption beds. This adsorbent has a specific gravity equivalent to that of seawater and has no net weight within seawater itself. However, weight of the metal cage occupies the majority of the weight of the adsorption bead of Figure 4, so weight is particularly imparted in seawater only by the metal. For example, in the case of the chain-binding method after pulling up, it is estimated that mooring cost declines to 62% if weight of this adsorption bed can be lowered by 50%, and mooring cost declines to 42% when weight can be lowered to 25%. Therefore uranium recovery cost may possibly be greatly lowered if a light cage material is used in place of the metal mesh of stainless steel. Also since this adsorbent was obtained in a length-wise continuous cloth-like form, if a method of mounting other than the assumed insertion into a cage as shown in Figure 4 is used (e.g., if a method is adopted of supporting the multiple adsorbent sheets streaming in the current), then an entirely different method would be is used for mooring than that utilized here.Clearly this technology, while totally practical and proven, is at a very early stage of development, and costs could be slashed in a number of obvious ways (i.e. piggybacking the equipment on other moorings like offshore windmills, switching the cages to a plastic with a specific gravity closer to water, or anchoring the sheets with light, high-strength fibers rather than cages and ropes).
Also, even assuming that we use the JAERI system as is, with a worst case uranium price 10 times that of land mining, uranium oxide comprises only a small fraction of the retail price of electricity. It accounts for 32% of the cost of nuclear fuel (Source), and nuclear fuel only comprises 20% of the total cost of nuclear power plant operation (Source). Thus uranium accounts for at most 6% of the final electrical bill. So if your current electric rate in the U.S. is $0.08/kwh, a switch to sea uranium would raise your electric rate to about $0.12/kwh. That's hardly an "end of civilization" price rise, and indeed is still just half the current retail price of electricity in Japan: $0.25/kwh (Source).
The above shows that cost will not be a significant barrier in harvesting uranium from seawater. So how much is out there? A lot:
Thus the amount of uranium in seawater was calculated and the results showed that the Black Current off Japan carries approximately 5.2 million tons a year. This amount is equivalent to the earth's remaining inventory of this ore. At present, Japan consumes about 6,000 tons of uranium per year. So even if only 0.1 percent of what flows along Japan can be recovered, the domestic demand for uranium can be supplied, and that is why I have continued to propose taking advantage of the uranium in seawater as an energy resource. Source
-- by JD
posted by JD @ 11:00 PM
9 comments
9 Comments:
One has to be skeptical to your URL source you quoted. They certainly have an agenda to promote nuclear energy since that's their business. Look at the number they give you, 25 tons of nuclear fuel only produced one ton of radioactive waste after re-processing. Isn't that amazing. It's too good to be true.
The real story is completely different. Anything that comes in close distance to highly radioactive material, they absorb the neutrons and they also become highly radioactive. It's like contageous. So at the end you have much more than the original radioactive material to deal with.
Here at my place we have a nuclear reactor which has run it's design lifetime, and needs to be disposed with. The whole reactor has become radioactive. So they have to solidify it by injecting huge amount of concrete into it, forming a solid piece of junk of 7000 tons. And they need to find a place to ship this junk to. After much huzzle they find a location in Virginia willing to take it. The transportation is another headache, they can't ship it over land, because even though it is solidified it is still radioactive and may contaminate the environment even just pass by. So they have to ship it over the ocean. And they need to build a railway from the nuclear power station to the harbor just to ship this huge piece of junk. And all and all. After spending 700 million dollars and the reactor has not been moved an inch, and they eventually gave up and have to let it just sit on its original location.
To calculate the cost of nuclear energy, you not only need to calculate the cost of mining and manufacturing the fuel rods, and building and operation of the station. You also need to count in the cost of disposing the waste and it's harm to environment. The radioactivity lasts tens of thousands of years before subduing in dosage. One generation enjoys the benefit of the electricity, but the next 20 generation will have to suffer living next to a harmful radioactive pile of waste.
Not to meantion that there are inheritant risks like Chernoble or Three Mile Island. Accidents like this will continue to happen in the future despite your best effort to reduce the risks.
When you count all these in, the electricity generated may not be enough to pay for all the clean up, for paying for the health problem caused by leaked radiation, damage to environment, etc. Nuclear energy is unworthy when you consider all the costs.
Not to meantion that we live in an era of terrorism. Any wider adoptation of nuclear technology and wider availability of nuclear material and equipment could only increase the chance that a terrism group may obtain, or even manufacture by themselves, and detonate nuclear devices.
If wider adoptation of nuclear technology resulted in greater chance of nuclear terror, such that it results in one major US city be wiped out, which would not otherwise happen. Then the cost is too much to bear and the whole venture of nuclear technology is not worthy pursuing.
Frankly I think national leaders of the world should get together and figure out a way to gradually dismantle the whole world not just of nuclear weapons, but of all nuclear technologies, equipments and materials. All existing stock piles of Uranium should be dis-solved and dissipated into the ocean, so that no person on earth could obtain a single gram of U235 any more.
I may be a bit extreme but that's the only way of guaranteeing a safe world that can survive the next one thousand years. Although unfortunately I do not see that could happen any time soon. Unfortunately it could take a few cities be wipe out, before people wake up and realize how dangerous nuclear technology could be, and could be stolen, and become determined to wipe out all nuclear stuff from possession of all human beings.
JD is blessed by being one of those who looks for solutions. It is merely a matter of personality and disposition.
In some eras of history, humans desperately need problem solvers like JD. In other rare, almost nonexistent eras, there is a shortage of problem seekers. Some people are doomseekers, drawen to visions of doom regardless of the actual status of the real world.
The nuclear promoters. Do you think it's acceptable for Iran to have to technology? And if not why not? Answers which stick heads in sands are not acceptable.
Good question WW. I believe (correct me if I'm wrong) that the non-proliferation treaty gives Iran the right to enrich uranium, and therefore they are operating within international law in doing so. For that reason, I support their position. The law is the law.
There is also a double-standard operating in the mid-east. If it is a danger to Israel for Iran to possess nuclear weapons, then it is likewise a danger to Iran for Israel to possess nuclear weapons. All parties should all be held to the same standard. To do otherwise will breed further resentment and violence. If it's not okay for Iran to enrich uranium, why is it okay for France or the UK to enrich uranium?
I think we're going to have to get used to lots of developing countries turning to nuclear energy. Otherwise, we are going to have to deal with either: a) massive coal burning, or b) electrical blackouts in developing countries, which will have their own unsavory side effects.
Finally, if the middle eastern countries aren't allowed to run nuclear power plants, they'll just keep burning their oil and gas, and make the transition harder than it has to be for everyone. We'll all be better off if those fossil fuels are used for more important tasks than generating electricity.
If wider adoptation of nuclear technology resulted in greater chance of nuclear terror, such that it results in one major US city be wiped out, which would not otherwise happen. Then the cost is too much to bear and the whole venture of nuclear technology is not worthy pursuing.
If the lights go out, there is a 100% chance of mayhem, misery and senseless death. The degree of damage would dwarf the destruction of a major US city. Nuclear terrorism may be dangerous, but it's not even remotely as dangerous as wide-scale permanent power blackout. You have to calculate the costs both ways, quantoken, and then compare them.
Wildwell,
One more comment about Iran:
A nuclear armed Iran may not necessarily be a bad thing. Once you've got nukes, you've got to factor getting nuked into your calculations. As W.S. Burroughs says, "Armed society is polite society". I think the record of history shows that nuclear weapons deter conflict, not promote it.
Wildwell,
If you don't respect the law, then you don't have any grounds for objecting to crime, or a repressive police state. "Rules are for the obedience of fools..." they'll laugh as they cart you off to the Gulag. I assure you, when it's your rights getting trampled on, you'll be dead serious in standing up for the law.
I don't have any problem with laws controlling nuclear power, provided that they are fair and equitable. I don't like the idea of laws which apply only to darky Islamics, but not to nice white people. That kind of double-standard just fuels more resentment.
Just curious, but what do you advocate as the solution to the Iranian impasse? Would you support an invasion of Iran to stop them from using nuclear energy?
I agree there should not be a double standard. It is equally dangerous for either Isreal or Iran or USA to own nuclear weapons. Any one is not more dangerous than the other, and one is not less dangerous than the other.
Put political ideaology differences aside, a weapon is a weapon. A nuclear bomb is a nuclear bomb. When it explode it does one thing: killing massive number of people, regardless of politics or regardless whose hand triggers it.
Those of you holding double standards saying some country should have nuclear bombs and some other should not. Are you trying to tell me that Isreal's bombs doesn't kill but Iran's does. Or that Iranian nuclear bombs work more efficiently and could potentially kill more people than American ones? Or are you trying to tell me that some people's lifes are more expensive than other peoples? Are you saying that if we kill one million people in the third world it's no big deal but if one million Americans died from a nuclear attack it is a much much bigger deal?
A life is a life, a weapon is a weapon, a killing is a killing. I do not see how double standard help us.
Honestly, I am just as equally uncomfortable as any one else to see a nuclear Iran. It will be a dangerous threat to world peace. But I have to emphasis that nuclear weapons in other hands: The Pakistanis, The Indians, the Americans, the Russians, are equally dangerous, and could potentially be equally effective to kill.
Some say Iran has connection to terrists, and we don't. First it's true that Iran has various connections with known terrirists. No denial of that. But there is no evidence that Iran is sending a suicider bombing team to American soil, or conducted any big plots against us over the years. If Iran is directly responsible for 9/11 we would have gone to Iran by now.
Second, imagine you are attending a wedding, and suddenly you and a few dozen guests are killed by some explosion. Is that not a terrible thing to happen? Is not that an act of terror? You might speculate it's a suicide bomber, but it could well be a bomb dropped from 30000 feet height. Does it matter which is the case? It doesn't matter to the dead because they are dead before they realize anything. It doesn't matter to the undead because they consider bombers 30000 feet above as terrorists as those more closer by. Yes, to that part of the world, they have a slightly different definition for terrirists.
Finally, some equals the event of an American city be wiped out by nuclear terrior acts to an event of mayhem caused by a massive and long lasting blackout. How could you compare the two. In the event of blackout we just pick up and move on. But do we just sit and mourn the dead after 9/11? We end up killing much more in Afganistan and Iraq.
If there is a nuclear terror event and a US city is wiped out, does any one honest believe Americans will just sit and cry? No! The next thing before any one realize, is a couple Muslim cities will be gone. And then Isreal will be wiped out, but not before it launches all its arsenals and wipe out the bulk of the Islamic world. And you bet out of the chaos there will be some more US cities be wiped out who knows by whom. Violence of that magnitude can and will escalade and it could well spell the end of the civilized world.
Get rid of ALL nuclear stuff is the only thing you can do to be safer. Meanwhile, there has never been and will never be world peace. War, disasters and catastropies are the norm. At least when we fight wars using some more primitive weaponries, we know at least the human race is safer to continue one.
All animals do fight within their own spieces. But most of them, when fight with each other, would use much less lethal techniques than those they utilize when hunting and predating. We humen seem to an exception.
http://www.sustainablenuclear.org/PADs/pad11983cohen.pdf
I agree with energyspin completely.
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