oil,nuclear power

hagopbul

oil have give us so much pain and blood .

it gives us problems in middle east,and with environment, opec, ...etc

so why we don't shift to the nuclear power just that simple (and for the nuclear wast if we have we can send it to the space)

so why not....

George Jones

Last Thursday, I went to a talk by a founding member of Greenpeace (and former president of Greenpeace Canada for nine years) who now promotes this.

hagopbul

ok when?
after 10000000000 year...

vanesch

It's the usual misunderstanding about nuclear waste.

Nuclear waste has 3 components:

- immediately most active and "final" ashes: the fission products: decay time of the order of 300-500 years

- small quantities of unwanted "minor actinides" which could be eliminated in future combustion cycles: decay time of the order of 10 000 years

- plutonium: actual "generated fuel" that is sometimes just left in the waste:
decay time of the order of 100 000 years. In countries with a fuel cycle, this is already extracted (to make MOX).

With decay time, I mean here: the time needed to be of the same (low) activity level as the original raw uranium ore that came out of the mine.

So the strictly necessary and uncompressible decay time to "background" is only of the order of a few centuries.

And now, think about this: how long does it take heavy metals in chemical waste to decay ?

Astronuc

There is a gradual renewal of interest in nuclear energy. Clearly there needs to be an alternative to the current reliance on fossil fuels. But there are also significant technical, envirnomental and economic issues involved. Switching to nuclear is not so simple and straightforward.

Keep in mind that as the demand for nuclear energy increases, it's cost will increase as well. It takes about 5-6 years to build a single nuclear plant, and in most countries, there is a shortage of qualified trades people who are needed to build the plants.


Disposal of nuclear waste in space is not an option. It cost about $10,000/kg to put something in orbit, and more if one wants to send it far away. That's not certainly not economical with respect to nuclear waste. Then there are the safety aspects.


Nuclear energy also does not address the current transporation infrastructure which is based upon personal mobility, vis-a-vis automobiles - and buses, trucks and aircraft. A large proportion of oil-based fuel is used in transportation. Trains can use electrical power, but only a small fraction of mileage is electrified.

hagopbul

it is always about the money right

Astronuc

Um - yep. Eventually it comes down to a rather simple economic proposition - at least in the industrialized modern age. Of course, one could be a nomadic hunterer-gatherer.

f95toli

Another problem with fission is that there is a limited amount of uranium available. Apparantly the prices are already going up. Now, we are not likely to run out any time soon (the estimates seem to range betwen 50-100 years) and presumably new deposits will be found, but that does not change the fact that fission -like oil- is only a temporary solution to the worlds energy problems.

Moreover, there is no way to completely separate civilian and military use of fission; if we want to world to use more nuclear power we will have to accept that ALL (or at least most) countries will need to have nuclear power plants of their own and quite a few will have to build enrichment facilites that can -in principle- also can be used to make weapon-grade uranium. Another problem is of course that even a civilian power plant can be quite dangerous if it ends up being located in the middle of a civil war, someone is bound to figure out that a nuclear meltdown is quite an efficient method of killing a lot of people and force any surviors to leave the area.

Kurdt

With fast reactors and reprocessed fuel we could have several thousand years.

russ_watters

Sort of. Right now the economics are driven by the politics and in the US, anyway, the politics are not favorable. In France, the politics are favorable, so they use nuclear power almost exclusively. Put quite simply, the hippies killed nuclear power in the US in the '60s and '70s, to the severe detrement of our country. Flower power will not drive a turbine. But the economics is what is now bringing it back. Electricity is getting expensive as oil prices rise. Other countries are seeing a resurgence of the dangerous attitudes that killed nuclear power in the US. Germany, for example, is setting itself up for an economic disaster right now with it's "environmental" policy for alternate energy, which does not include nuclear power.

That huge drawback of nuclear power, the waste containment issue, was also invented by "environmentalists". It simply doesn't exist. For the short-mid term (the next hundred years or so), on-site storage plus reprocessing makes the Yucca mountain project irrelevant. For the longer term, well, if you reprocess the fuel, there is little that needs to go anywhere except a nice, safe, landfill. Anything worse can be stored in a mountan, but it only needs to be secure for a hundred years at a time. The 10,000 year lifespan engineering criteria of the Yucca project is just crack smoking, pure and simple. You cannot design a structure for that kind of longevity, even if you had to, and in this case, you don't. If our civilization deteriorates enough that we can't maintain the facility or create a new one a hundred years from now, the need for it to be secure goes away as well.

So no, on this issue, the politics is driving the money more than anything else.

russ_watters

To expand on Kurd's statement, the 50-100 years estimate comes from so-called environmentalists who have so far succeeded in keeping reprocessing illegal in the US. Imagine - "environmentalists" who are against recycling!

I'm a little on the distrustful side, so when I see people doing such irrational things, I think that unless they are incredibly naive, there must be another motive at work. Ostensibly, though, reprocessing was outlawed (by presidential order) for nuclear proliferation reasons.

f95toli

True, with reproccssing it would last much longer.
However, as far as I understand the problem with reprocessing is that it requires more or less the same type of plants as are used for enrichment (it is basically isotope separation) which just brings us back to my main point about the security issues (I am not usally paranoid, but having a lot of enriched uranium floating around makes me nervious, even if it is only reactor-grade).

I am not a big fan of nuclear power, in my view it is too dangerous and too difficult to control. Imagine a world where all the exisiting fossil fuel power plants were replaced by fission reactors; from a CO2 point-of-view it would be a good thing; but the drawback is that there would be a LOT of fission reactors around; many of them in poor countries and quite a few in places that are politically unstable. Remember that the worlds energy consumption is rapidly going up.

I wouldn't really have a problem with fission as a short term solution (i.e. replacing the current generation of reactors in countries that already have nuclear power) if it wasn't for the fact that it is likely to kill off all funding to research into viable -but in the short term very expensive- alternatives such as fusion. I don't really have much faith in the political system when it comes to research funding, the only way to make sure the neccesary funds become available is if the general public and industry start fearing that we will run out of energy; only then will there be enough pressure on the politicians to invest the hundreds of billions of dollars that will be needed.

mgb_phys

Nope it's basically chemical - you remove the waste products that you don't want, you aren't trying to extract pure U235. The technology to enrich U has nothing to do with reactors it's more precison machining.

Reactor fuel is a pretty useless starting point for a weapon. The same non-proliferation treaty that we keep going on about says that we (nice safe countries with nuclear weapons) are supposed to provide the uranium for them in return for them not trying to play with the stuff themselves.

We don't seem to mind have high pressure gas pipelines or Methyl-cyanide plants in poor countries - presuably because an accident only effects the locals.

So India, Pakistan, South Africa, Brazil are allowed them but Switzerland, Holland, Germany, Sweden aren't.
The only country I can think of that built nuclear power plants primarily for power rather than weapons research is Canada.

Fusion + short term + viable - aren't often used in the same sentance.

f95toli

I admitt I don't know much about the technology, but isn't the technology (which as you say is mainly chemical) monitored precisely because it CAN be used to extract Pu from fuel coming from commercial reactors?

Well, I think we can safely forget about providing uranium for others. I would be VERY suprised if a majority of countries in the world would accept having to get all their fuel from a minority that was sitting on all the facilties for making reactor-grade uranium. Look at the current situation with Iran, whether or not they want to enrich uranium for military use is irrelevant; the point is that they can -with some justification- claim that it is in their national interest not having to rely on someone else for their uranium even if it is for civilian reactors.

You got a point. But you are also right that it only affect the local population, a nuclear meltdown in a badly maintained power plant will affect a large area. I grew up on the east coast of Sweden and we were quite badly affected by the Chernobyl disaster (bad luck with the wind). The hunters in the are were I am from still have test the meat from time to time. And as you know Sweden is quite far from Chernobyl



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Short term is something like 50 years in this case.
I was at a superconductivity conference recently and went to one of the talks about the magnet system in ITER. One of the older speakers had been working on the magnet design for over 20 years and since the project is now done (the design has been finalized) he had recently started working on the next generation (DEMO).
In his talk he pointed out that a large portion of the people in the audience would be dead before DEMO goes online (even in the best case scenario); and even the youngest people in the room (PhD students) would be close to retirement.

K.J.Healey

How many reactors would have to be built to replace 100% of our (USA's) consumption of oil as a power source (non auto)?
lets say with 1998 numbers:
Oil Only 36 quadrillion BTU's consumed (1 year)
A nuclear PWR plant can output at 1500MWe, which leads to a calculation of about 803 PWR plants to replace Oil alone (Not counting natural gas and coal).

Is 803 a big number? Well its about double what the WORLD has in operation at this moment.

I could only imagine how much our demands would increase during the lengthy production of these plants. But then again maybe power plants in the future will be able to output more.

mgb_phys

The technology to reprocess spent fuel into MOX is the same as to extract Pu from reactors. This is the only way to get Pu, although you generally use a different reactor design if your aim is Pu rather than power - you can see this is the design of most 'civil' reactors from the 40s/50s!
The technology to enrich U235 doesn't require you to have a reactor - just very good precision machinery for centrifuges or a lot of copper for race tracks.


We are quite happy to get our oil/gas from countries we don't exactly trust!
The UK is building a new fleet of Trident missile subs against our tradiational cold war enemy - who will also supply 80% of our natural gas.

But the UK or Norway building a few dozen coal fired power stations would effect you a lot more - I don't think the lakes and forests in Sweden have recovered from the UK's acid rain yet.

Actually you probably also receive more radiation from UK coal power statiosn than from Chernobyl - how dangerous this is depends on the particular isotopes and where they end up, you tend to get a lot of Thorium from coal which isn't as bad as the Ceasium from Chernobyl which concentrates in biology a lot more.

Astronuc

The 104 operating nuclear reactors in the US supply about 20% of the electricity. Several produce less than 1 GWe. Most modern nuclear plants produce ~1.1 GWe, and the newest largest ones are aimed for ~1.5-1.6 GWe. Replacing all the oil and coal plants would require about 300-400 new nuclear plants (depending on capacity), and that would leave natural gas peaking plants for reserve.

There is always reserve generation, just in case the grid or plants experience an unplanned outage or disruption.