Wednesday, June 13, 2012

880 Millisieverts/Hr Radiation on Reactor 2's 5th Floor at #Fukushima, Found by Quince the Robot

Quince No.2 did not find visible damage to the building interior, but got 505.6 millisieverts of radiation exposure for the 4-hour work.

Earlier, human workers went down to the Torus Room of Reactor 2 trying to photograph the level of water inside the Suppression Chamber with an infrared camera to estimate the location of the leak. They were unsuccessful, probably due to steam on the surface of the water.

Reactor 2 is more scary to me than Reactor 3 or Reactor 4. No visible damage anywhere, yet it has released the most radioactive materials. Thermocouples keep failing, and such a high radiation out of nowhere.

From Sankei Shinbun (6/13/2012):

2号機5階で毎時880ミリシーベルト 福島第1

Fukushima Daiichi (I) 880 Millisieverts/hour on 5th floor of Reactor 2


TEPCO announced on June 13 that it conducted the survey of the interior of the Reactor 2 building using a robot, which measured the 880 millisieverts/hour radiation near the concrete floor on the 5th floor right above the reactor. The 5-year cumulative maximum radiation exposure for nuclear workers (100 millisieverts) would be reached in about 7 minutes at that location. TEPCO thinks it will be difficult for [human] workers to enter the 5th floor. According to the company, there was no visible damage to the interior of the building.


The improved version of "Quince", robot developed in Japan for disaster response support, went up to the 5th floor and measured the radiation. The concrete floor with the highest radiation level this time is about 2-meter thick, and about 3.5 meter away from the top of the Containment Vessel.


The robot got 505.6 millisieverts of radiation exposure in the 4-hour survey, and the 9 [human] workers got the max 3.95 millisieverts.

There is no data yet on TEPCO's sites (English or Japanese). I'll post when they do.


Anonymous said...

"scary"? naw's the only leaky tomb so far.
if i'd get a free wish, i'd wish no.1, two and four would be the same amount of "scary".
maybe a domesticated zombie, e.g. a zombie with enough exposure to a TV running mass-media (reactors no1, no3, no4), is less scary then a zombie behind glass walls(no2)?

Anonymous said...

Poor workers. Anyone see the photo of the critically ill nuclear worker in the hospital burn unit? Terrible way to die..7 long as they consider they may not know all the areas of high radiation. Those badges--dont trust them much..but hey..its at least something for comparison sake. Not much however.

Workers will get sick, have cancers, have heart attacks, deformed children, diabetes..and no proof what caused the damage. A FREE GET OUT OF JAIL FOR TEPCO!

Anonymous said...

And they can't wait to restart Ooi.


Steve From Virginia said...

800+ mSv/hr. Wow ...

The bosses should put a camera into the pressure vessel by way of yet another pipe. Probably nothing inside, just a tube open at the bottom.

If the fuel melted straight down and burned through the bottom of the containment, the damage would be invisible from the torus room. Rads from the core would find their way everywhere within the building. Water would be leaking straight down as well, into the ground under the reactor.

Lead bricks: build an area where workers can automate the two big gantries and use them to remove the spent fuel. That job could start tomorrow ...

Anonymous said...

Over year and still nobody knows exactly what the situation is. How can they honestly state everything's safe and good? This is such a simple realization to make, yet the majority of the human populace remains ignorant.

Anonymous said...

I do NOT like the reference to floor thickness and distance from reactor vessel at all. It means someone somewhere considered the possibility that some of it might be gamma from the reactor vessel. But that would mean insanely high doses at the source.

Does anyone know if this is just gamma, or beta+gamma, or what?

Anonymous said...

> Does anyone know if this is just gamma, or beta+gamma, or what?

Beta is harder to measure. It's gamma. Probably from nuclides deposited by the steam - Unit 2 was steaming for a long time (a month or so) back then.

Anonymous said...

Thanks, Quince.

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