Some comments on other's views:
The only nuclear reactors that cannot meltdown are ones that have a negative power gradient at high temperatures – i.e. they switch themselves off. The only design for that is one that has existed for 50 years but has never been developed, which uses a large bed of fuel with water flowing over it rather than a high density fuel core. Why has it not been developed? 70% of all nuclear power r&d has been from Defence budgets. The fuel bed reactor would never fit on a submarine, as the "core" and the supporting plant is big. So while the Canadian Candu reactor design is safer than the 1970’s generation of reactors its still a pressurised water reactor that can lose coolant. There is a reason the Chinese are building their reactors as fuel bed ones, but its a very new technology as the r&d has not been done and we don't know how they will fare or how expensive they will actually be. Aldo China has a LOT of land and a polictical stance to build them wherever they want, shall we say. Hands up who wants 20 or more acres of Nuclear Power station next to their village?
Nuclear power is not as cheap as fossil fuel. Far from it. If you include the lifetime costs of fuel and dealing with waste and you take away the government levy on energy bills and the massive costs of an accidents then you end up with a very expensive power generation method. This is the best argument against nuclear power in my opinion – it costs too much to do correctly. For instance we don’t know how expensive its going to be to store all the high level radioactive waste that will remain lethal for millennia – we don’t know how/where or even when we are going to be able to long term store it. The fuel waste at Torness is still there and its been running since the 1960s – why? There is nowhere to put it so it stays in the cooling ponds rusting.
An example of how nuclear power does not pay for itself can be seen in the story of Bradwell – it was found that the nuclear core was dangerously fragile as a result of neutron bombardment and was at risk of cracking open. Stop the power station? No – wrap the core in ductile copper wire to keep it running. Why? It had not yet saved enough money to pay for its own decommissioning after over 35 years of service. Its now no longer running after the nuclear watchdog closed it down, and I believe it had to be bailed out by public money.
Nuclear power is not a zero emissions technology. Ask the people who work and live near the mines (and its getting increasingly difficult to mine) on land poisoned by the mercury used to dissolve the heavy metals out of the ore, the dirty power stations used to power the factories and mining which are almost entirely in developing or economically challenged countries. Then there are the costs for the transport of fuel and waste from continent to continent. Even looking at CO2 emissions there is a significant cost to nuclear power production, though admittedly much less than fossil fuels.
There is a lot of rubbish spouted about Nuclear Power, unfortunately. There is blinkered view of the technophiles (of which I am one, just not blinkered I hope) who miss the fact that it is actually a glorified steam engine using a dangerous fuel and the real sexy technologies are in the renewables, efficiency and microgeneration, there is the blinkered/desperate view of the economists and politicians who miss or deliberately avoid the true lifecycle costs of a unit of nuclear generated energy and there is the unfortunately blinkered view of some greens who concentrate on mutated babies rather than economics, understandably from a human point of view, but it will not win the argument.
Then there is the increased threat of nuclear weaponised nations and terror attacks on nuclear installations or using “primitive” weapons. I have been reliably informed that a physics graduate with a second class degree, a well stocked workshop, 10 kilos of weapons grade nuclear material, some semtex and a half decent physics and engineering library could build a very dirty kiloton yield atom bomb. Looking at what I know I totally believe I could.
However Nuclear power is the wrong way to go because it costs too much. Its that simple from my point of view. The problem is we aren’t investing anywhere NEAR as much in alternatives, even now, as we are in Nuclear so we are left walking down a one way road.
As far as Japan is concerned building Nuclear power stations in an earthquake zone is stupid, and was opposed at the time for the very reasons being seen now – not rocket science. And just so we don’t think how clever we are in this country by comparison, for instance building a nuclear power station on a shingle beach is stupid particularly when in recorded history a storm has changed the coastline by over a mile and normal everyday longshore drift requires trucks to run 24 hours a day 365 days a year to return the tens of tons of shingle removed from in front of the station. Dungeoness, its called.
Also the danger from a loss of coolant and a meltdown is not the molten blob (its called the elephants foot in Chernobyl), it’s the steam explosion that results from a bare surface of the core being exposed as the water level drops. No containment building that would be feasible or economically possible can withstand that explosion, and it creates a LOT of radioactive dust from the building and core material ejected. It’s the reason that the helicopter pilot who repeatedly dropped sand on the Chernobyl core continued to fly. He knew that he had absolutely no hope of surviving the required repeated flights through the plume of smoke, but he was a trained nuclear hazmat person and knew if it was not done then 10000s could die. Not an exaggeration. He survived 3 weeks.
There is a perception that this is a problem with shoddy Russian technology, and there is some truth to that. But I refer you to Three Mile Island incident. A reactor of the same basic design as many many reactors and the proposed new reactors in this country was something like 4 hours way from a catastrophic failure generating a steam explosion etc. after its coolant systems failed. That was some time ago, and things are much better now, but it only takes one, or sabotage etc. and power stations are built by the lowest tender.