TEPCO: Nearly All Nuclear Fuel Melted At Fukushima No. 3 Reactor

mdsolar (1045926) writes "Almost all of the nuclear fuel in the No. 3 reactor of the Fukushima No. 1 nuclear power plant melted within days of the March 11, 2011, disaster, according to a new estimate by Tokyo Electric Power Co. TEPCO originally estimated that about 60 percent of the nuclear fuel melted at the reactor. But the latest estimate released on Aug. 6 revealed that the fuel started to melt about six hours earlier than previously thought. TEPCO said most of the melted fuel likely dropped to the bottom of the containment unit from the pressure vessel after the disaster set off by the Great East Japan Earthquake and tsunami."

Re:So.. what?

[Noah Haders]

I see this as qualified good news. A power plant had a total meltdown but the world didn't end. There was no China syndrome situation. Maybe we can start to talk about nuclear risk more pragmatically.

I think this means

[MobyDisk]

fuel at the No. 3 reactor began melting at 5:30 a.m. on March 13

I think this confirms that that they should not have flooded the reactor with seawater because the meltdown had already happened by the time they made that decision. They flooded the reactor on March 15th, as a last ditch attempt to prevent a meltdown. But it was too late to save the reactor since the fuel was already completely melted. So all the seawater did was let more nuclear material escape.

Or, alternatively, they should have flooded it with seawater days ahead of time. The tsunami was March 11th, so perhaps had they made that decision on March 12th it would have been in time to prevent the worst of it? Ehh... maybe not.... the reactor foundation was probably already damaged by that point. :-(

Re:So.. what?

[Anonymous Coward]

I see this as qualified good news. A power plant had a total meltdown but the world didn't end. There was no China syndrome situation. Maybe we can start to talk about nuclear risk more pragmatically.

Can we start by discussing the wisdom of building them near the coast in earthquake prone areas known to suffer regular and massive tsunami disasters?

Re:So.. what?

[Chas]

As soon as we can discuss TEPCO being idiots for ignoring their engineers and not building the infrastructure as required.

Re:So.. what?

[khallow]

The tsunami continues to release contaminated material and water into the environment too. The debris washed into the sea wasn't all biodegradable and green. And things like lead and mercury have a much longer half life than things like tritium. The two events aren't compared fairly and this just another example of that.

This is why we need NEW reactors

[WindBourne]

Seriously, the mistake that everybody is making is stopping new ultra-safe reactors from replacing these old second gen reactors. Companies like Transatomic can make it so that the reactor can not fail.

Idiot speaks: "So.. what?"

[dtjohnson]

A large amount of radioactive material was released into the ocean where it will remain in the food chain for decades. Approximately 100,000 people are unable to return to their homes and a large area of land in a country where land is scarce and precious is uninhabitable. But...that's just the short term. Long term: Japan will have to deal with electric power shortages for years until their power generation can be rebuilt with new technology. Hundreds of billions of dollars will have to be spent over the next 20 years to decommission the mess at Fukushima and attempt to decontaminate the surrounding downwind land. All of this was avoidable...but happened because the resident village idiots were able to prevent realistic plans from being implemented for electric power generation at Fukushima. The Onagawa power station was closer to the earthquake epicenter and yet it survived undamaged thanks to a losing battle by the resident village idiots to ensure that it was built according to their idiot plans. They lost at Onagawa but 'won' at Fukushima. Idiots who said...why spend a lot of money on a bigger seawall at Fukushima? Idiot engineers at GE who said 'there's no need for a failsafe design for something that will never happen,' and idiots who say 'what's the big deal about a meltdown?'

Re:So.. what?

[ShanghaiBill]

The total amount of radioactive material put out by a coal power plant is actually larger, per unit of energy produced, than a nuclear power plant.

No it isn't. The claim that it does can be traced to a single paper written in 1978 by a scientist at Oak Ridge National Lab. The paper only considered nuclear plants during normal operation. Yet more than 98% of radiation from nukes is released during accidents, which the paper ignores. The paper also ignores the biological characteristics of the radiation. Nukes emit radioactive cesium, iodine, and strontium, which tend to bio-accumulate. Nearly all the radiation in coal is thorium, which has no biological role, and just remains inert in the ash.

There are plenty of good reasons to oppose coal. But "radiation" isn't one of them.

Re:So.. what?

[Wycliffe]

Don't worry about CO2, the plants need it to live, the more there is, the more they grow.

I've heard this argument before and I know plants need co2 but is co2 really the bottleneck and does increasing
co2 cause plants to really grow faster to compensate? If co2 is the bottleneck and an increase in co2 causes
plants to respond in step and keep co2 stable them that's fine but that doesn't appear to be what is happening.
Co2 levels appear to be increasing so obviously this feedback loop is either not working or not working fast enough.
If a 5% increase in co2 causes plants to use 1% more co2 then we still have an increase of 4% so yes plants
might help a little but they aren't really a solution.

Re:So.. what?

[mdsolar]

It is not just inert, but screened by the ash. The ash is (slightly) vitrified soil from the forest where the coal came from. It is like other low carbon soil in its uranium concentration. So there just is no increase in background radiation. The claim that there is is like saying using a bulldozer exposed new uranium. It does, but it buries just as much as it exposes.

Fossil fuels are depleted in carbon-14 so when they are burned, the amount of carbon-14 in our food is reduced. So, fossil fuels use cuts our radiation exposure. Not a good reason to use them, but the effect is opposite claimed in that paper, which is really a disgrace for ORNL.