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Nuclear Power

Discussion in 'General Science Discussions' started by Yellow Fang, 27 Nov 2013.

  1. Yellow Fang

    Yellow Fang Veteran Geek

    Location:
    Reading
    I am not too bothered about the danger of accidents or the waste storage issue. If a nuclear power station does go bang, it does not actually kill many people. The bigger problem is that you have to depopulate an exclusion zone, more for the perceived risks than the real ones. Nuclear waste is mostly a non-issue in terms of leakage of radioactive materials. Not much of it is produced. The fissile products decay to almost nothing after a century. The longer-lasting actinides can be separated from the fissile products, and either vitrified in glass, or re-used as nuclear fuel. What I do wonder about is nuclear weapons proliferation. There are some types of reactor which do not require enriched uranium. The CANDU reactor design uses natural uranium. Thorium reactors are in theory safe in not generating raw materials for bombs. Some reactor types can be fuelled with material from old nuclear warheads. In general, however, most reactor designs, such as pressurised water designs, need enriched uranium. Uranium for power generation is enriched in centrifuges to a much less degree than for nuclear weaponry. Nevertheless, once a state has the centrifuges, it can secretly continue to make higher grade material for a weapons programme. There is an international nuclear inspection body whose job it is to ensure nuclear power stations are properly maintained, and that they are not secretly building bombs. However, to me that is not a fail-safe system, in particular when faced with an uncooperative state. Nuclear power probably has a big role to play in providing carbon-free energy to a growing world population eager to improve their living standards. But the more countries that can generate weapons grade nuclear materials, the more likely these weapons will get used, IMO.
     
  2. beanz

    beanz Staff Member Staff Member

    Nuclear proliferation is hugely worrying.

    While there is a justifiable reason for countries to have fission reactors, there will be the problem of potential misuse for weapon technology. On a different thread I raised the issue of fusion reactors which are at present in the early development stage but which IMHO represent the world's best chance of using nuclear energy to safely generate electricity. If we had widespread use of commercial fusion reactors by now, the legitimate need for fission reactors would have diminished - even raising the possibility of international legislation banning their use, perhaps.

    As it is, governments have for decades been too slow to invest in fusion with anything like the funds and urgency it needed. So we are playing catch-up while the fossil fuel reserves become more and more depleted, oil becomes ever more scarce and the likelihood of an 'energy crisis' within our / our children's lifetimes becomes seemingly unavoidable.
     
  3. Yellow Fang

    Yellow Fang Veteran Geek

    Location:
    Reading
    I went on an open evening tour around a nuclear fusion research centre near Oxford. I think the project is called JET and the centre is in Culham. It was pretty impressive. They reckoned they will have it cracked in twenty to thirty years. There is a joke about fusion always being thirty years away, but they said that this time they really thought it. When I visited several years ago they said they had got it working for about thirty seconds. It consumed more electricity than it generated, but the point is they got it working. The next stage was a much bigger project, ITER in France. The guide said they thought they could get fusion to work for eight hours at a stretch, rather than thirty seconds. After eight hours they may have to rewind the mechanism. OTOH, they might find a way to make it work constantly. It was very interesting. The guide said that it was a collaborative project with many countries contributing to the costs, which are no doubt vast. No doubt too that the cream of engineers work there. The plasma is heated up to 100 million centigrade and accelerated around a torus (doughnut). I think there is a giant electromagnet in the centre driving it all. I think basically it works like an electric motor, but I am not sure. I did not quite understand that bit of the tour, although I tried not to look blank. When your tritium ion collides with your deuterium ion at that speed, you get helium, a neutron and a lot of radiation, which you can turn into heat, then steam, then electricity. There is another fusion research project that attempts to use lasers to fuse deuterium and tritium ions together. It is American led, I think, but I think also the Rutherford Centre, also near Oxford, is involved with that. It would be pretty bad luck if neither of those two approaches come to anything.
     
  4. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
    I remember hearing about fusion reactors about 20 years ago when France started playing around with it. Then they said it was 20-30 years away...
     
  5. 0-markymark-0

    0-markymark-0 Über Geek

    I saw an interetsting program on tempertaure on BBC. It was all about measuing 1 degree celcius. They visited a fusion site in Oxford, probably the one mentioned above, and in the experiment it reached temperatures of 300 million degrees! I just can't get my head around those sort of figures. It was 20 times hotter than the sun!
     
  6. Yellow Fang

    Yellow Fang Veteran Geek

    Location:
    Reading
    20x hotter than the centre of the sun. The surface of the sun is a relatively cool 5,800°C.
     
    0-markymark-0 likes this.
  7. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
    5,800 x 20 = 116,000. NOT 300,000,000
     
  8. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
  9. beanz

    beanz Staff Member Staff Member

  10. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
    Quite a few countries are, there is lots more of it and don't need to get fuel from less desirable countries.
     
  11. illogicalparadox

    illogicalparadox Regular Geek

    fission or fusion?
    these structures are badly designed - fission...they are typically designed for a 100 year storm
    let me quote simple examples in the UK, and what they are not designed for
    1. Storegga Slide 8k BP
    2. 1755 Lisbon earthquake
    3. meteor impact and so on
    4. wolverine and 3 mile island almost erased from the history books...like 1 2 and 3, och well

    These places most likely had/have a design life of 25-40 years..which they always extend.
    The waste cannot be stored safely, tuts..and god forbid should it be spread about like Chernobyl (vast country) and fukushima
    Most likely wind solar thence thorium are the way to go

    Iter (puny cost shared) - they are arguing over a couple of billion quid - they should declare themselves a financial institution and we could wheel barrow in trillions in cash
     
  12. Yellow Fang

    Yellow Fang Veteran Geek

    Location:
    Reading
    Apparently the Chinese are very interested in fusion. I attended a talk given by someone from the Culham nuclear fusion research centre when I attended this year's Ecobuild. He said the Chinese are very worried that lack of energy will inhibit their economic growth, so they aim to get fusion up and running by 2030. I cannot remember what the issues were with Thorium, but there were some. The Indians are interested in it because they have Thorium resources.

    Personally I am not too bothered if there is the odd nuclear calamity, provided it is not as bad as Chernobyl or near somewhere highly populated. Very few people actually die in these accidents. I am not convinced there is no safe way of storing the waste either. There are two types of nuclear radioactive waste materials, the actinides and the fission products. The actinides are the very heavy elements, and they can be re-used as fuel. The fission products can be vitrified in glass, and then dumped underground in concrete bunkers for a couple of hundred years. It's more a political problem than an engineering problem.
     
  13. Yellow Fang

    Yellow Fang Veteran Geek

    Location:
    Reading
    I heard the director of the JET fusion project in Culham on the radio this morning. He was being interviewed for the Life Scientific. He said fusion was still 40 years away.
     
  14. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
  15. Yellow Fang

    Yellow Fang Veteran Geek

    Location:
    Reading
  16. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
    Going back in and seeing how it's effected the wildlife.
     
  17. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
  18. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
    http://www.bbc.co.uk/news/business-39424634
    Looks like the nuclear plan might be on hold, better start rolling out that renewable soon.
     
  19. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
  20. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK