More Rain = Worst drought

[Underseer]

Originally posted by Combat Ingrid
Do you have any reference to that? I have a hard time believing it but if it's true it's great.

I don't know where he's getting his 95% number from, but there's always fissile material left in "spent" fuel rods. The question is how economically feasible it is to reprocess the spent fuel rods. As the other poster said, it's more expensive than just digging up new uranium, but it should be cheaper than yucca mountain, shouldn't it? Even if it's a little more expensive than what they're planning at Yucca, I think reprocessing would be worth it from an ecological and political standpoint, but if it's a lot more expensive than storage... well...

Ugh. Not fun stuff to think about.

[Underseer]

Originally posted by Zkribbler
[...]

BTW: The Israelis have been doing wonders in getting the price down on desalinized water. The Aussies could probably use of few of their plants. It's better than watching their agricultuarl sector dry up and blow away.

Considering all the dire warnings we've been getting about an impending fresh water shortage, you have to wonder why more governments aren't investing in desalination research.

[Dinner]

There are a couple of different approaches to recycling spent fuel rods. The one the US department of energy is trying out is spelled out here: http://www.anl.gov/Media_Center/Fron...2003/d5ee.html

Basically you reburn the rods in a slightly different type of nuclear reactor to destroy most of the longest lived elements meaning that the remaining waste will remain radioactive for around 1,000 years before reaching safe levels.

The French have taken this idea a step further by using breeder reactors. They follow the US plan but instead of storing the remaining waste for 1000 years they reprocess the remainder into new rods (this requires the remaining material to be reground up and centrifuged again) so that they have mostly unused material which they fashion into new fuel rods. These new fuel rods are then reburned in a traditional reactor. Since so much of the old rods are reused their is very little waste. Even without using recycling the amount of nuclear waste produced world wide since 1945 would only fill one foot ball stadium; nuclear energy is very efficent at producing a lot of electricity for not a lot of waste.

At the end of the day there is no such thing as risk free energy. There is only risk minimized energy and nuclear is that energy. Fossil fuels harm our environment with pollution, hydro is good but damages rivers and we have no mare large rivers to dam, wind is nice but unreliable, solar is extremely expensive and uses a lot of heavy metals in their contruction, while geothermal only works in certain areas. Nuclear is our only good solution.

[Zkribbler]

If I recall correctly, U.S. breeder reactors (such as the Fermi plaint) used liquid sodium as their cooling fluid.

The problem with this is (a) as part of the cooling process, it passed over the radioactive material becoming radioactive itself; (b) radioactivity is a corrosive, (c) if the corrosive liquid sodium ever ate through the cooling pipes and came in contract with air, it would explode, and (d) having your nuclear cooling fluid explode is a very, very bad thing.

[Provost Harrison]

Re: More Rain = Worst drought

Originally posted by trev
Australia is currently suffering a severe drought which has halved agricultural production, resulted in many irrigation licencees being given a zero water allowance, effectively shutting down the irrigation business and killing many orchards and other crops. All major cities are on water restrictions, some smaller cities are limited to minuscle water allowances each day, enough for cooking and about 10 mins of shower use per household. Massive fires have burnt and are still burning in some states, being fought by firefighters from Canada and New Zealand as well as our own.
Yet the Australia Bureau of Metereology has announced that Australia's rainfull for 2006 was 19mm above average (about 5%). The problem is the rain fell in large amounts in the North and Northwest Tropics of the country plus in the Western Interiors of the continent, all sparsely populated areas with limited agricultural activities. Many of the main agricultural areas had their driest year on record. Either the population of Austdalia needs to be redistributed, or the rainfall does. Both are not easy options.

Well, build really, really long aqueducts

[Ogie Oglethorpe]

(b) radioactivity is a corrosive,

Huh?

[Provost Harrison]

Well, that bit of nonsense aside, sodium reacts vigorously with water and water vapour and will oxidise fairly rapidly in air...however it would have very little reaction with metallic pipework.

[Straybow]

Originally posted by Zkribbler
If I recall correctly, U.S. breeder reactors (such as the Fermi plaint) used liquid sodium as their cooling fluid.

The problem with this is (a) as part of the cooling process, it passed over the radioactive material becoming radioactive itself; (b) radioactivity is a corrosive, (c) if the corrosive liquid sodium ever ate through the cooling pipes and came in contract with air, it would explode, and (d) having your nuclear cooling fluid explode is a very, very bad thing.

The main problem with LMRs is that of shutdown. The primary coolant can't be permitted to drop to ambient, but must be heated above the melting point of 98°C when the reactor isn't running. The heat and the reactive properties of liquid sodium do make maintenance and repair work a tricky prospect.

Second, the Fermi plant was just an experimental one. The defunct Clinch River Breeder Reactor Plant Project was a pressurized water reactor, not liquid metal cooled reactor.

Third, breeder reactors don't treat spent fuel rods. They treat the U238 "depleted uranium" waste from making U235 fuel and turn it into Pu239.

Oerdin is talking about something else. Reprocessing of spent fuel requires pulverizing the fuel and chemically removing the fission products and decay products until the U235 (or Pu239) purity is high enough to be used in a reactor.

So, you still wind up needing a Yucca Mountain or some such to safely stow the nasty fission and decay products. But at least you put the million tons of U238 to use.

Wasn't this thread about global warming conspiracies or something? Hmmm. Carry on.

[Edit: can't count]

[Straybow]

Originally posted by trev
Yet the Australia Bureau of Metereology has announced that Australia's rainfull for 2006 was 19mm above average (about 5%). The problem is the rain fell in large amounts in the North and Northwest Tropics of the country plus in the Western Interiors of the continent, all sparsely populated areas with limited agricultural activities. Many of the main agricultural areas had their driest year on record. Either the population of Austdalia needs to be redistributed, or the rainfall does. Both are not easy options.

Whaaaat??? This has never happened before in all of human history! Rainfall in one part of a continent, and drought in another? That's impossible...

Oh, you mean that happens all the time? Nevermind.

[Dinner]

Straybow, I believe the approach the Atomic Energy Agency is talking about in thaty 2003 paper was to use breeder reactors to break down the longest lived (that is the longest half life) elements so that the remaining material will be "safe" (that is the radioactivity will be low enough that it won't be much of a bother) in just 1000 years instead of 10,000 or 30,000 years we currently have. Once the long lived stuff is broken up and done away with then the remaining material can be reprocessed and reused. Yes, in the end you will still end up with waste material which must be stored but we're talking about a tiny fraction of the existing amount.

[Zkribbler]

Originally posted by Provost Harrison
Well, that bit of nonsense aside, sodium reacts vigorously with water and water vapour and will oxidise fairly rapidly in air...however it would have very little reaction with metallic pipework.

Well that would make sense...sodium is a metal after all. As I remember it, the danger came from the radioactivity itself corroding the pipes.

Ogie draws exception to this statement. I read this fact in some book decades ago . I did go out on the net to see if I could find some conformation, but the only statements were by people running their mouths in forums such as this...nothing scientific.

However, Straybow's statement that more recent US breeders use pressurized water as a coolant moots this whole point.

[Fake Boris]

Originally posted by Oerdin
wind is nice but unreliable

We talked about this already. It's quite reliable.

[Straybow]

Originally posted by Oerdin
Straybow, I believe the approach the Atomic Energy Agency is talking about in thaty 2003 paper...

You expect me to read your linky? You are such a pill.

Ah, the main thing they're talking about is converting fuel oxide into metal electrochemically, which eliminates messy pulverization. Then they process the metallic fuel to eliminate the (low level) fission products and leave the nasty stuff in the fuel.

That's still a drop in the bucket compared to the 98%+ U238 that is discarded in making the fuel. With U238 breeders we would meet half our electrical demand for the next 100 years without mining Uranium.

[Traianvs]

Originally posted by Oerdin
A better way would be to build nuclear power plants. It is superior in just about every way plus it costs much, much less on a per Kw basis.

Currently our dependency world wide on nuclear plants is very low, percentagewise I mean. If we were to rely more on nuclear plants we'd have to build thousands more, and uranium will consequently be depleted soon enough just like oil resources will be in the next century or so.

But it's always nice to have an alternative at hand. The only thing that bothers me is that Australia has huge potential for solar energy, but its environmental policy doesn't improve and encourage implementation and development of sustainable alternatives, which is a shame really, because unlike countries like Belgium for example, they do have better opportunities.

[Traianvs]

Originally posted by Straybow

Originally posted by Oerdin
Straybow, I believe the approach the Atomic Energy Agency is talking about in thaty 2003 paper...

You expect me to read your linky? You are such a pill.

Ah, the main thing they're talking about is converting fuel oxide into metal electrochemically, which eliminates messy pulverization. Then they process the metallic fuel to eliminate the (low level) fission products and leave the nasty stuff in the fuel.

That's still a drop in the bucket compared to the 98%+ U238 that is discarded in making the fuel. With U238 breeders we would meet half our electrical demand for the next 100 years without mining Uranium.

What exactly are U238 breeders? In layman's terms