Wednesday, February 20, 2013

#Fukushima I Nuke Plant: Reactor 1 Torus Room Max Radiation 920 Millisieverts/Hour

(UPDATE) Video and photos in the latest post.


After successfully drilling a hole through the 1st floor of Reactor 1 building and finding no obstruction, TEPCO sent workers to lower the camera, thermometer, and dosimeter through the hole into the torus room in the basement.

The highest radiation dose was right above the water, at 920 millisieverts/hour.

It took 20 workers 2 hours and 25 minutes to do the first day of work, with maximum radiation exposure of 1.78 millisievert. From TEPCO's February 14, 2013 handout (see my post), the air radiation level at the hole on the first floor of the reactor building is 10 millisieverts/hour, and at 1.2 meter above the hole it is 2 millisieverts/hour.

From TEPCO's Handout for the Press, 2/20/2013:


Anonymous said...

And a tent around all of this is the only protection they came up with, for the last two years.
Japan is toast.

Atomfritz said...

This is really bad news.
The fact that the radiation increases in the lowest meter indicates that this torus is leaking, too.
Radioactive sludge particles leaving the leak increasingly precipitate on the floor.
In a few years when the torus begins to rust thoroughly and to leak massively the situation will probably become quite difficult.

Atomfritz said...

They just released a video.
It looks way murkier and rustier there than I expected. Scary!

JAnonymous said...

Yeh, the torus is leaky. Not very surprising, all those hundreds of millisieverts need to come from somewhere.

A small detail (maybe it's a trifle, maybe not) that is worrying me, is how the radiation level picks up towards the bottom of the room. The water should shield radiation, but if the level is higher, it means we are getting closer to a source (or getting a shorter unobstructed path). But maybe it's nothing. It's a 16% increase from OP200 to the bottom, but with respect to the highest reading, it's still small (remember water is a shield though).

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