Plutonium

[wildwood]

I recently heard some scientist say on the radio that the world's plutonium resources will be depleted in another 80 years or so. How do they know this as there are vast areas of even Australia where it may still be discovered.
If this this true where do we go from then for energy, not that I will be around to worry about it then.

[jake-the-peg]

Firstly I suspect you heard that the world's Uranium resources would be depleted.

Plutonium is not naturally occuring and has to be extracted from the fuel rods of spent nuclear reactors.

I never could hack geology so I can't tell you how they know what the uranium resources are but I'd not be too worried if there's 80 years left.

The next generation of nuclear energy will come from Fusion recators which will operate in the same way that the sun does by joining Hydrogen nucleii to make Helium.

This is very difficult and work has been going on on it for 50 years or so.

The position at the moment is that Fusion was achieved at the JET torus in Oxfordshire but the design was such that you got less energy out that went in.

Right now in Southern France ITER is being built which will produce more energy than it consumes but will still not be an operational power plant.

DEMO is planned to be the first fusion power plant (probably in Japan because they let the French have ITER) That's likely to be about 30 - 40 years.

You'll never get "Free energy" but the radioactive waste will be short lived (no more 100,000 years half-life stuff) and the raw material can be extracted from the sea.

And as a bonus because the technology is not weapons related if Iran builds a fusion reactor - nobody goes to war!

For more about fusion see www.iter.org

[wildwood]

Thanks Jake. Yes, it could very well have been that he said Uranium, I wouldn't know the difference anyway. All that concerned me is that I always thought the nuclear reactors would be producing energy for ever and a day from very little base material. I have become a bit suspicious about those broad statements that scientists make publicly about matters that are above the layman's daily conversation.

[jake-the-peg]

There was a great deal of concern about Uranium supplies in the past which is why there was interest in "fast breeder" reactors.

These reactors run off of the plutonium created as the initial Uranium fuel breaks down.

There was a fast-breeder experimental facility at Dounrey in Scotland but the discovery of large scale Australian deposits and the difficulty of the technology basically made it obsolete.

I have to say it's as well, having had the opportunity to visit the site in 1987 when it was active I can say it was a very scary place!

[BillyBB]

In January, the National Audit Office said that the cost of decommissioning ageing power sites had risen from �12bn to �73bn.

Free energy forever!

[jake-the-peg]

Ah now Billy this is exactly what I'm talking about.

These are fission reactors - the type we have now. Your Uranium fuel breaks down into a really nasty cocktail that you have no control over.

In Fusion reactors there is no radioactive waste from the fuel because stable helium is the result. The only thing that becomes radioactive is the fabric of the reactor itself.

This means that you can make intelligent choices in what you construct it of and avoid materials which produce long-lived radioisotopes.

At ITER for example the majority of the waste will be safe after 100 years of storage. The remainder for the entire plant is 6000 tonnes

Currently the UK has over 100,000 tonnes of radioactive waste in storage

And because decomissioning is planned and built into the design it will cost only $355 million to decomission.

And frankly what is the alternative?

Use less? you're seeing what happens when fuel prices rocket right now.

I guess we could just use electricity when the wind blows or there's a tidal surge.

Unless someone comes up with a new and highly efficient energy storage technology there really isn't a long term alternative