I love that 1 ton number for breeders. They are obviously having such an impact today with the average gigawatt plant using about 175 tons per year of which about 100 tons is newly mined.
Certainly. No argument with that, given the average 1 gigawatt plant today is on the once through cycle...
Quote:
Even after several decades there is no breeder that functions within stated parameters. That 1 ton number is as likely as the world getting 20K nuclear plants built in a century let a lone a few decades.
If breeders were so successful then why are so many countries looking for ways to get rid of the spent fuel?
Because uranium, for all the talk of uranium being scarce, is cheap enough to be considered garbage, and plutonium even more so.
Joined: Oct 12, 2004 Posts: 1647 Location: Davis, California
Posted: Wed Jun 01, 2005 12:09 am Post subject:
Well usable Uranium is scarce even if uranium as a whole is abundant. 99%+ of the uranium ore is not usable conventionally. _________________ Joseph Stalin "It is enough that the people know there was an election. The people who cast the votes decide nothing. The people who count the votes decide everything. "
Joined: Nov 21, 2004 Posts: 579 Location: ~170ft/lbs@0rpm (on my bike)
Posted: Wed Jun 01, 2005 12:12 am Post subject:
ECM wrote:
I love that 1 ton number for breeders. They are obviously having such an impact today with the average gigawatt plant using about 175 tons per year of which about 100 tons is newly mined.
You do realize how many 'normal' reactors there are compared to breeder reactors, verdad?
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If breeders were so successful then why are so many countries looking for ways to get rid of the spent fuel?
From the breeders, or plants in general? There's been a very anti-nuclear sentiment recently, so much so that some of the largest producers like France are debating whether to overhaul their reactors or decommission them...
Popular opinion is easily swayed by big business, our 'automobile' culture is a very big business/industry. But they would never dream of inflating the public's fear of nuclear power while downplaying the negative (and much more numerous/serious) effects of ff's and our beloved automobile, now would they?
The writing's on the wall mofo! _________________ "Humankind cannot gain anything without first giving something in return. To obtain, something of equal value must be lost. "
There is no way coal has an EROEI of 3 to 1 if it is being mined with oil.
If the EROEI is 3 to 1, you would need 1MMbtu from oil to get 3MMbtu of coal.
Costs: $9.14 (1MMbtu of oil)
Revenues: $7.80 (3MMbtu of Central Appalachia coal)
Revenues - Costs = -$1.34
Maybe you better find us a cite for that 3 to 1 number. Where did you get it? I sincerely hope you got that number from a source, and didn't just pull it out of your butt. Tyler!
Joined: Feb 20, 2005 Posts: 2786 Location: Uppsala, Sweden
Posted: Wed Jun 01, 2005 6:52 am Post subject:
It seems this subject is being discussed time and time again no matter what.
Why aren't breeder reactors used? Because nuclear fuel is very cheap. No matter what the EROI is, breeders aren't profitable with todays low uranium prices. When uranium gets scarce and expensive breeders will be used.
For how long will there be enough uranium?
Quote:
Finity of nuclear fuel: In theory nuclear fuel is finite. So is solar power, since solar power is the radiation from the big fusion plant in the sky. In practice they are both sustainable.
Let's do some counting. Let's say all primary energy is changed to nuclear. Let's also say energy use increases 50 %. Today nuclear energy is 6-7 % of all primary energy. That means we need a 15-fold increase, and then 50 % on top of that. Today the reserves of nuclear fuel are enough for about 200 years.
200/15=13,33 years
13,33/1,5=8,9 years
Spooky huh? Well, no, because we can get breeder reactors. That means we get 60 times as much energy from the fuel.
8,9*60= 533 years
Ergo= If we get breeders up and working we are set for quite a long time.
But this is not all ( I sound like a TV-Shop guy), you also have thorium! There is 3 times as much thorium in the ground as there is uranium [...] [and thorium can also be bred]. But there is more! There is also insane amounts of uranium solved in the sea! We are not really sure how to get this uranium into the reactors, but when (if) we do, we are just as home free as if we manage to harness fusion.
_________________ Peak oil is not an energy crisis. It is a liquid fuel crisis.
Joined: Apr 28, 2005 Posts: 3647 Location: West shore Lake Eire, MI, USA
Posted: Thu Jun 02, 2005 5:24 pm Post subject:
Starvid wrote:
It seems this subject is being discussed time and time again no matter what.
Why aren't breeder reactors used? Because nuclear fuel is very cheap. No matter what the EROI is, breeders aren't profitable with todays low uranium prices. When uranium gets scarce and expensive breeders will be used.
For how long will there be enough uranium?
Has anyone else been tracking the Megatons to Megawatts program? I have been following it for years, if they wanted to they could have replaced all Uranium mining for USA consumption with scrap Russian nuclear warheads FOR TEN YEARS STRAIGHT!!!
The price of Uranium is so low right now because they are replacing half of all Uranium consumed by the USA with scrap warheads. Given the choice between weak Uranium prices and Russia keeping these weapons in its stockpile I will choose weak prices every time.
http://www.usec.com/v2001_02/HTML/Megatons_status.asp _________________ Oxygen: - An intensely habit-forming accumulative toxic substance. As little
as one breath is known to produce a life-long addiction to the gas, which addiction invariably ends in death.--Isaac Asimov
Joined: Sep 25, 2004 Posts: 4542 Location: Boston, MA
Posted: Thu Jun 02, 2005 6:12 pm Post subject:
Quote:
Tyler_JC wrote:
1. Coal with an EROEI of 3 to 1
There is no way coal has an EROEI of 3 to 1 if it is being mined with oil.
If the EROEI is 3 to 1, you would need 1MMbtu from oil to get 3MMbtu of coal.
Costs: $9.14 (1MMbtu of oil)
Revenues: $7.80 (3MMbtu of Central Appalachia coal)
Revenues - Costs = -$1.34
Maybe you better find us a cite for that 3 to 1 number. Where did you get it? I sincerely hope you got that number from a source, and didn't just pull it out of your butt. Tyler!
OK, I meant to write 4 to 1. I read it somewhere and I can't remember where... and I'm not going to look ! _________________ "www.peakoil.com is the Myspace of the Apocalypse."
There is no way coal has an EROEI of 3 to 1 if it is being mined with oil.
If the EROEI is 3 to 1, you would need 1MMbtu from oil to get 3MMbtu of coal.
Costs: $9.14 (1MMbtu of oil)
Revenues: $7.80 (3MMbtu of Central Appalachia coal)
Revenues - Costs = -$1.34
Maybe you better find us a cite for that 3 to 1 number. Where did you get it? I sincerely hope you got that number from a source, and didn't just pull it out of your butt. Tyler!
OK, I meant to write 4 to 1. I read it somewhere
No you didn't. I'm accusing you flat out of making that number up.
Quote:
and I can't remember where... and I'm not going to look !
Right... We're supposed to believe that the EROEI of coal is 3 to 1 (or, oops... 4 to 1) on the word of some 12 year old who "can't remember where he read it" and is too lazy to provide a citation. Very convincing.
Middle East Oil 30 or more quality varies
Tar Sands 1.5
Hydro Power 45
Coal 25 according to accessibility suspect figure
Nuclear 5 to 20 according to assumptions suspect figure
Solar 4 to 10
Corn Ethanol negative
Q: I heard that the U.S. has 200 years of coal left, so why can't we just replace the oil with coal?
A: It is not meaningful to speak of a certain number of years left re: coal because that assumes a constant demand between now and then. If coal were to replace oil then it would last closer to 50 years than 200. Importantly, while coal can be used for some applications that oil is currently used for, oil is the best fuel for transportation. It would be impractical to power cars with coal.
Since coal has less energy stored in the same amount of mass than oil, more coal (by weight) is needed than oil to provide the same amount of power. Indeed, the railroad industry moved away from coal-fired steam engines to diesel-electric locomotives because an engine that uses petroleum-based diesel fuel is inherently more efficient.
Because the energy density of coal, roughly speaking, is about half that of oil, one would need coal weighing approximately twice as much as the equivalent amount of gasoline in order to power the car. That would be equivalent to about 12 pounds of coal for every one gallon of gasoline, which weighs about 6 pounds. And even then, while twice as much coal contains about the same amount of energy as gasoline, it does not burn as hot as gasoline does, so the equivalent amount of coal would not provide the equivalent horsepower to gasoline burned in a car's engine.
Concerns continue to mount over the sulfur and carbon oxides that are released when coal is burned. These chemicals fall back to the earth as "acid rain" and accumulate in bodies of water often killing all plant and animal life. The acidification of lakes and rivers in the Northeastern U.S. from Midwestern coal plants is well-documented.
Over the past decade a scientific consensus has developed on the issue of global climate change. Carbon dioxide released from coal plants is a major contributor to the accumulation of "greenhouse gases" in the atmosphere. These gases trap additional heat that usually escapes from the earth. An overall heating trend can cause erratic temperature changes and extreme weather events.
But now we aren't talking about uranium anymore.... _________________ "www.peakoil.com is the Myspace of the Apocalypse."
It seems this subject is being discussed time and time again no matter what.
Why aren't breeder reactors used? Because nuclear fuel is very cheap. No matter what the EROI is, breeders aren't profitable with todays low uranium prices. When uranium gets scarce and expensive breeders will be used.
For how long will there be enough uranium?
The current reactors require very expensive processing of the Uranium. Breeders do not require this processing. Uranium mined at $300 dollars/kg for breeders would be far cheaper than the current cost of $1000+/kg for most current reactors. Breeders are also supposed to be cheaper to build and smaller.
The only thing that troubles me about uranium is that a lot of young people and even children might get hurt mining it.
There's enough of it to power humanity for a while, so that's not the problem. The problem is that Congolese women, old men, and children are being forced by illegal and fraudulent Chinese and Indian entrepreneurs to dig the stuff up, with an ax and shovel or with their bare hands, facing torture and death if they don't obey.
Greed, exploitation and violence for profit, that's what troubles me.
Joined: Feb 20, 2005 Posts: 2786 Location: Uppsala, Sweden
Posted: Fri Jun 03, 2005 8:36 am Post subject:
ECM wrote:
Starvid wrote:
It seems this subject is being discussed time and time again no matter what.
Why aren't breeder reactors used? Because nuclear fuel is very cheap. No matter what the EROI is, breeders aren't profitable with todays low uranium prices. When uranium gets scarce and expensive breeders will be used.
For how long will there be enough uranium?
The current reactors require very expensive processing of the Uranium. Breeders do not require this processing. Uranium mined at $300 dollars/kg for breeders would be far cheaper than the current cost of $1000+/kg for most current reactors. Breeders are also supposed to be cheaper to build and smaller.
The main cost of nuclear fuel is not the uranium itself but the enrichment of the fuel and the manufacturing of fuel elements et cetera. Do you mean this is not necessary in a breeder? That you only have to dig the ore out of the ground and throw it into the breeder? I don't think so. What is your source?
Breeders are not thought to be cheaper than conventional reactors. They are thought to be more expensive. According to the nuclear industry they will only become profitable if uranium prices return to pre-1980 levels.
Making the reactors small will only make the electricty even more expensive since you lose the economies of scale. _________________ Peak oil is not an energy crisis. It is a liquid fuel crisis.
Joined: Jul 18, 2004 Posts: 198 Location: S. Yorkshire, UK
Posted: Fri Jun 03, 2005 1:40 pm Post subject:
Quote:
The main cost of nuclear fuel is not the uranium itself but the enrichment of the fuel and the manufacturing of fuel elements et cetera. Do you mean this is not necessary in a breeder? That you only have to dig the ore out of the ground and throw it into the breeder? I don't think so. What is your source?
It is true that breeders don't need enriched uranium - in fact they use depleted uranium.
However, instead of an enrichment plant you need a plant capable of extracting plutonium from spent fuel - this is a considerably more costly and difficult process. It is plutonium that actually fuels the reactor, the uranium is converted to plutonium as a useful side effect. The problem is that before the new plutonium is useful, it has to be extracted and concentrated, before it can be formed into new fuel.
Not only that, but because the fuel in a breeder operates at higher stresses, fuel changes need to be more frequent and fabrication quality needs to be higher.
Due to the increased complexity of a breeder fuel cycle and higher capital costs of the reactors, it is generally though uneconomic if Uranium prices remain below about 3-5x what they are today.
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