(June 2, 2012 at 12:24 pm)Welsh cake Wrote: Trying to find a way of vaporising all the wastage from their fast-breeder reactors.
Old nuclear technology and the cheap bastards (well, it's not really cheap, maintaining older designs when we have newer designs made specifically to deal with the faults of the old) will be the death of Nuclear.
Only way nuclear can move forward is to have safe, small reactors that utilize molten salts instead of water -- the benefit of the molten salt method is that you can have the radioactive material inside the salt pellets that becomes released ONLY when the temperature of the reactor is within certain limits.
Too hot and the reactor (the thorium design) expands. Still too hot? Active fan assembly fails, a plug drops and melts, the chamber drains and the reactor cools. Too cold and it shuts down, leaving bricks of congealed salt with radioactive crap locked inside. Not that overheating is easy.
Wikipedia Wrote:The first is that thorium absorbs more neutrons if it overheats, the so called Doppler effect[33]. This leaves fewer neutrons to continue the chain reaction, reducing power. The second effect has to do with thermal expansion of the fuel[34]. If the fuel overheats, it expands considerably, which, due to the liquid nature of the fuel, will push fuel out of the active core region, reducing the chain reaction, with no damage to components. Solid fuelled reactors cannot expand their fuel by much, without damaging it, because it is tightly contained in fuel rods. These virtues of the LFTR are attained by integrating the coolant with the fuel. Coolant and fuel are inseparable, so any leak or movement of fuel will be intrinsically accompanied by a large amount of coolant. Thus, the coolant follows the heat source.
The best part about them? The amount of radioactive material to power a thorium reactor is much, much less compared to BWR's and PWR's -- possibly because the Thorium design can be scaled to a very small form factor (the Xerox Parc talk I went to had the speaker quoting refrigerator sized micro-reactors) and be very safe (from tampering) because you'd need to be able to separate the salts out in a very specialized high temperature oven, something that endemically limits underfunded-to-medium funded nuclear terrorism. Left alone, the slabs of radioactive salts would just sit cold and moderately radioactive -- the perfect fuel source to truck around.
I love nuclear. I really do. But I cannot stand the nuclear industry and their insistence on using OLD designs. Designs that are unsafe, expensive, require HUMAN intervention all the time, need GOVERNMENT SUBSIDIES for insurance (no US based nuclear facility would be economically viable otherwise -- Check it yourself Chuck -- that's why Nuclear will currently be MORE expensive than solar and possibly other sources), etc,.
The future of Nuclear's soul will be Generation 4 and beyond (MSRs, etc).
http://en.wikipedia.org/wiki/Liquid_fluo...um_reactor
http://en.wikipedia.org/wiki/Generation_IV_reactor
Personally, I think MSR's are the way to go -- if Nuclear's biggest heel is big ass facilities that need giant insurance subsidies AND expensive SPENT FUEL storage, then small, micro isobreeder MSR's would be ideal.
Slave to the Patriarchy no more
