Because they lost power to the water cooling system, they needed to vent the pressure that's building up inside.My suspicion is that as the temperature inside the reactor was rising, some of the metal cans that surround the fuel may have burst and at high temperature, that fuel cladding can react with water to produce zirconium oxide and hydrogen.That hydrogen then will be part of the gases that need to be vented. That hydrogen then mixes with the surrounding air. Hydrogen and oxygen can then recombine explosively. So it seems while the explosion wasn't directly connected with the nuclear processes, it was indirectly connected, because the hydrogen was only present because of what was going on in the reactor core.
quote: what it boils down to is that an area contaminated by nuclear meltdown is uninhabitable for *much* longer than any other kind of power plant destroyed. That and the widespread effect on people and the wildlife is much longer lasting as well.
quote: If you find nuclear power plant so safe, are you living near one already?
quote: When you operate a coal plant, the harm is spread all around and avoidable
quote: Nuclear accident: 1 in 10,000,000 chance of dying Scalding: 1 in 5,000,000 Food poisoning: 1 in 3,000,000 Falling out of bed: 1 in 2,000,000 Drowning in bath: 1 in 685,000 Work accident: 1 in 43,500 Car crash: 1 in 8,000