Kevin_Lowe
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- Feb 10, 2003
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This is obviously an issue, but not insurmountable. The amount of waste generated is very small overall--U235 is only about 5% of the reactor fuel and about 4% gets fissioned. The majority of radioactive waste products will decay away within about 300 years. The long lived waste and the transuranics like plutonium are a bigger problem. The plutonium can be recycled back into existing reactors in what is called MOX fuel and burned. France does this successfully. It extracts more power out of fuel. In addition, the plutonium and other transuranics can be put into liquid metal fast breeder reactors and burned while breeding more plutonium for other reactors.
You will typically find that the people advocating this as a solution can't demonstrate that it's cost-effective, and it indeed adds a significant cost to the already questionable economics of fission reactors. There's a world of difference between what is possible and what is financially sound and when pro-nuclear speakers slide from talking about what is cost-effective to what is possible you need to get on your guard very quickly.
The useless fission product waste needs to be stored for about 300 years. There are several processes to consolidate the waste. My favorite is to vitrify the waste into glass and store it in stainless steel canisters. Where to store it permanently is another question...salt domes are favored as they have been stable for hundreds of thousands of years.
Salt domes (whatever they are) may have been, but civilizations have not been unfortunately. Nuclear advocates also tend to gloss right over the moral issue of leaving behind us wastes that will be dangerous long after the people who benefited from their creation are dead. Yes, our civilization does lots of things that are not in the best interests of future generations, but that doesn't make it okay to do some more.
The answer is not easy and certainly not ideal. Very few things in the energy or any heavy industry are. Compared with the waste generated from the oil, coal and chemistry industries, I think nuclear looks favorable. The high level nuclear waste from all the plants in the US would fit on a football field to a depth of about 10 feet (3m) or so.
I'm not at all sure what this oft-repeated line of argument is supposed to prove. So it's small... what follows?
I guess we have been through this before, but I have to inform others.
First, the reason breeder reactors have not been developed is because they have not been needed. The once through fuel cycle is cheaper and since uranium has been plentiful and cheap, breeders were abandoned. Any long term use of nuclear power will require breeders to extend the useful like of the planet's uranium. (initially, the first plants built were breeders as the amount of uranium available was unknown.)
As I said, breeders are an extra expense which needs to be accounted for before conventional fission is a long-term prospect. Nuclear advocates tend to skate over this. They like to try to establish that conventional fission is cost-effective (which takes some doing), and then very quickly pass over the fact that if conventional fission is to be a long-term, large-scale proposition we are also going to need breeders to fuel them with all their associated problems.
I've seen some people - apparently seriously - suggest that the nuclear club should have an enforced monopoly on breeders and the rest of the world should build fission reactors and be dependant on the nuclear club for fuel for them. I can't see that being sold to the world.
Commercial breeders would not bomb builders due to contamination of the fuel during the cycle. It would be stupid to build a giant commerciall plant to make pu for weapons as it would require new technology to build the weapons.
To breed pu for weapons, one needs is a small uranium pile, a bunch of very pure graphite and you can make pu for weapons. Bomb material must be relatively pure pu239 and therefore the reactors must operate at low burnup. A commercial breeder would not make weapons grade pu. The US and France and others already have nuclear weapons and had them without using commercial breeder technology--production plants specifically designed to produce plutonium. The US can build all the breeder plants we need...we already have thousands of nukes. Pakistan built weapons by enriching uranium--no breeder necessary. The proliferation game is just nonsense.
That's assuming we can make this technology widespread without anybody we don't like adapting it to weapons production. Also nobody ever said that breeders were the only proliferation risk, merely that they were one.
Now, about the 1000MW plant dismantling itself if the sodium cooling is lost...this is just wrong. Completely wrong. EBRII performed loss of sodium coolant testing that proved the inherent safety of the system. The sodium was dumped and the fuel remained intact and was able to stop the reaction and maintain integrity. A loss of sodium accident is unlikely as the sodium is at low pressure anyhow.
That was a 62.5MW experimental breeder designed to do exactly that stunt. It has not been demonstrated that this scales up to 1000+MW reactors, although it's a promising demonstration, since the US government killed that project. The fast breeder designs actually in use today do not have this safety feature to the best of my knowledge.