Guardian UK: Fukushima fuel rods may have completely melted

[marmar]

Fuel rods inside one of the reactors at the Fukushima Daiichi nuclear power plant may have completely melted and bored most of the way through a concrete floor, the reactor's last line of defence before its steel outer casing, the plant's operator said.

Tokyo Electric Power (Tepco) said in a report that fuel inside reactor No 1 appeared to have dropped through its inner pressure vessel and into the outer containment vessel, indicating that the accident was more severe than first thought.

The revelation that the plant may have narrowly averted a disastrous "China syndrome" scenario comes days after reports that the company had dismissed a 2008 warning that the plant was inadequately prepared to resist a tsunami.

Tepco revised its view of the damage inside the No 1 reactor – one of three that suffered meltdown soon after the 11 March disaster – after running a new simulation of the accident. ...............(more)

The complete piece is at: http://www.guardian.co.uk/world/2011/dec/02/fukushima-fuel-rods-completely-melted

[rucky]

1. Wouldn't that be an America syndrome?

[FBaggins]

2. Nope

Their description was "melted and bored most of the way through a concrete floor, the reactor's last line of defence before its steel outer casing, the plant's operator said."

That's like saying the "last line of defense if you don't count the two most substantial lines of defense"

At the bottom of the drywell is between 1-3 meters of hardened concrete, followed by a thick steel shell, followed by several meters of hardened steel-reinforced concrete. Burn through all of that and you start talking about some kind of "syndrome" (which is silly since the actual "syndrome" was never physically possible).

Regardless, the current estimate is that it burned through about 70 cm of that first layer of concrete in the first couple days and has been sitting there ever since.