Nuclear Energy Density

[Trim50]

Thought this worth sharing...

Material Energy Density (MJ/kg) 100W light bulb time (1kg)
Wood 10 1.2 days
Ethanol 26.8 3.1 days
Coal 32.5 3.8 days
Crude oil 41.9 4.8 days
Diesel 45.8 5.3 days
Natural Uranium 5.7x10^5 182 years
Reactor Grade Uranium 3.7x10^6 1171 years

Table 1 Energy densities of various energy sources in MJ/kg and in length of time that 1 kg of each material could run a 100W load. Natural uranium has undergone no enrichment (0.7% U-235), reactor-grade uranium has 5% U-235. By the way, 1 kg of weapons grade uranium (95% U-235) could power the entire USA for 177 seconds. All numbers assume 100% thermal-to-electrical conversion.

[MarkJ]

I only need a few grams of Uranium

[night0wl]

Nuclear is going to have to be part of the energy future. Its just how do you make it safe and cheap enough at the same time.

[sailorboy1]

Having been in nuclear power for 11 years in the past I can say that it is already cheap and safe. But then all the 50s monster movies started and the fear developed, so it got soooo regulated. When nuclear power started the concern in the industry was that the power would so cheap to produce that it would hard to meter. Of course the anti-nucs are never going to agree on the safety.

[delmarrey]

I think the biggest problem with nukes is the waste. Why can't they just pump it back into deep oil wells that have been all pump out.

If I remember right the earths core is radioactive. By pumping it back into deep wells would put it close to another source that is already contaminated. And don't they already bury it underground now?

Or has this already been explored?

[David M]

France does not seem to have any problems. People fear what they do not understand.

[Celestialsailor]

Originally Posted by David M

France does not seem to have any problems. People fear what they do not understand.

Good!!! Lets ship our Nuclear waste to france!

[bastonjock]

i sail past a nuclear rector,it has some sort of pump out in the sea,the water boils and gurgles,looks quite ominous.

We had a public debate in Scotland regarding the disposal of waste nuclear material,it was proposed that the Mountains around the aptly named "loch doom" would be drilled and deep shafts created and then the waste would be stored in conatiners down these deep shafts.The area hed never had an earth quake and the main argument was that the rocks were amongst the oldest on planet earth and were solid.

At the height of the debate,the first ever earth quake was recorded in those mountains,kind of killed the safety argument.

The UK gov has just sold out Nuclear power stations to the French as they are ahead of the game on Nuclear power stations,we have a program to build 18 new stations.The big problem in europe is that the european mainland has no natural resources,the EEC is at the mercy of the Russians and Ukrainians,they had another dispute this year and the russians switched off the Ukrainians and they i turn switched off Europe,it had been switched back on in the last few days.It is a form of black mail, the russians have europe by the privates and they squeeze when they want more money.

I am not comfortable with nuclear power,i just dont see an alternative as the UK,s natural gas runs out.

[bg9208]

Most of the electricity generated in France is nuclear. Having experimented with a few different types of reactor, France has chosen to build pressurised water reactors, to the Wesinghouse design. Having all 50 or so reactors of the same design and type makes them cheaper to build, run and maintain. With regard to waste, a statment by Christain Bataille the Minister responsible for eneryg might put the problem in context."French technocrats had never thought that the waste issue would be much of a problem. From the beginning the French had been recycling their nuclear waste, reclaiming the plutonium and unused uranium and fabricating new fuel elements. This not only gave energy, it reduced the volume and longevity of French radioactive waste. The volume of the ultimate high-level waste was indeed very small: the contribution of a family of four using electricity for 20 years is a glass cylinder the size of a cigarette lighter". It was assumed that this small amount of high-level waste would be buried in underground geological storage and in the 80s French engineers began digging exploratory holes in France's rural granitic regions where there is deep underground already a significant level of natural radiation.

[GordMay]

Originally Posted by bg9208

... "French technocrats had never thought that the waste issue would be much of a problem. From the beginning the French had been recycling their nuclear waste, reclaiming the plutonium and unused uranium and fabricating new fuel elements. This not only gave energy, it reduced the volume and longevity of French radioactive waste...

See also the interesting & infrmative article:
Nuclear Wasteland ~ by Peter Fairley
at:
IEEE Spectrum: Nuclear Wasteland

Which concludes:
“... But until or unless breeder reactors are commercialized that can truly burn up all the residual fissile material found in spent fuels, reprocessing will simply concentrate high-level waste in a form that’s hotter and harder to handle, exchanging one nuclear waste headache for another.”

[sailorboy1]

"i sail past a nuclear rector,it has some sort of pump out in the sea,the water boils and gurgles,looks quite ominous."

The pump is most likely a cooling water pump and I doubt it is boiling water. The pump has nothing to do with a plant being nuclear. If the plant was using coal, gas. or oil to make the steam for the tubines it would have that same "pump".

As far as the waste; 99% of the waste is of no danager (well maybe if you eat it it would make you sick, but not due to the radioactivity). Most is classified as radioactive waste due to various regulations, not on whether it ready measures any activity.

[TexSail]

Originally Posted by delmarrey

I think the biggest problem with nukes is the waste. Why can't they just pump it back into deep oil wells that have been all pump out...

It depends on the formation, but often what is left behind is salt water and/or small amounts of natural gas. Either way, I would be concerned that the radiactivity might migrate with formation liquids. The migration is slow, but some of the spent materials have a very long half life.

IMHO, special caves in stable, less populated areas are probably the best bet.

Each form of energy has some risks and practical downsides.

[GordMay]

Originally Posted by Don Lucas

... As far as the waste; 99% of the waste is of no danager ...

The vast majority (99%) of radiation in nuclear waste is given off from spent fuel rods. However, fuel rods make up a relatively small percentage of the volume of waste.

The largest volume of nuclear waste is composed of the leftovers from the mining process. This waste, however, doesn't give off much radiation.

[David M]

Originally Posted by bastonjock

i sail past a nuclear rector,it has some sort of pump out in the sea,the water boils and gurgles,looks quite ominous.

We had a public debate in Scotland regarding the disposal of waste nuclear material,it was proposed that the Mountains around the aptly named "loch doom" would be drilled and deep shafts created and then the waste would be stored in conatiners down these deep shafts.The area hed never had an earth quake and the main argument was that the rocks were amongst the oldest on planet earth and were solid.

At the height of the debate,the first ever earth quake was recorded in those mountains,kind of killed the safety argument.

The UK gov has just sold out Nuclear power stations to the French as they are ahead of the game on Nuclear power stations,we have a program to build 18 new stations.The big problem in europe is that the european mainland has no natural resources,the EEC is at the mercy of the Russians and Ukrainians,they had another dispute this year and the russians switched off the Ukrainians and they i turn switched off Europe,it had been switched back on in the last few days.It is a form of black mail, the russians have europe by the privates and they squeeze when they want more money.

I am not comfortable with nuclear power,i just dont see an alternative as the UK,s natural gas runs out.

Canada is the top uranium producer with about 23% of the worlds uranium. Their political system is stable and are friendly with your country as well. Australia is a close second. You don't need uranium from any unstable countries to keep the plants going.

Steam condensers require lots of cooling water from the river. That's what you are seeing, waste heat. They are on a completely different loop three to four times removed from the liquid that flows through the reactor.

http://en.wikipedia.org/wiki/Uranium_market

[Rodz]

David M .... I think you missed the point made by bastonjock ... He was talking about GAS ... natural gas! that was switched off .... not URANIUM.

IMHO ..... If we want it or not the nuclear energy is going to stay with us for a looooong looooong time. There is no cheaper and less polluting alternative. The only concern is to keep it safe.

Heck!! how about the small power plants on the nuke subs?? People are sleeping with reactors!!