Thursday, August 4, 2011

#Fukushima I Nuke Plant: 3.6 Sieverts/Hr at Stack Drain Pipe for Reactors 1 and 2

Another solid "sievert" number from Fukushima I Nuclear Power Plant.

Maybe I shouldn't be writing in sieverts. It minimizes the significance somewhat. It is 3.6 sieverts/hour, or 3,600 millisieverts/hour, or 3,600,000 microsieverts/hour. No humans of any age should be exposed to that kind of radiation, not even the TEPCO workers.

From what I've found, only Mainichi Shinbun (only a brief mention) and Nikkan Sports (tabloid newspaper covering mostly sports-related news) carried the news from Kyodo News. (But I couldn't find it at Kyodo News site.)

Nikkan Sports citing Kyodo News (8/4/2011):


Investigating the 10-plus sieverts/hour radiation at the bottom of the main exhaust duct for the Reactors 1 and 2 at Fukushima I Nuclear Power Plant, TEPCO announced on August 4 that 3.6 sieverts/hour radiation was detected at the drain pipe that connects to the bottom of the main exhaust stack for Reactors 1 and 2.


The pipe is for draining rainwater from the bottom of the exhaust stack. 3.6 sieverts/hour radiation was measured at several meters from the exhaust stack. TEPCO has designated the area around the pipe as off-limits.


The 3.6 sieverts/hour spot was found by 4 workers measuring the area as part of investigation to find out why the radiation at the exhaust stack had such high radiation exceeding 10 sieverts/hour. The maximum radiation exposure for the workers was 2 to 3 millisieverts.

Here's the photo released by TEPCO on August 5. The orange cone to the left marks the location where 10-plus sieverts/radiation was measured on August 1:

This is the photo of the location with 10-plus sieverts/hour. The pipe that extends right from the exhaust stack is the one that measured 3.6 sieverts/hour:

I have to wonder where the rainwater has been draining, all these 4-plus months.


Anonymous said...

Does anyone know HOW FAR a carbon-based(CB) worker has to be from EITHER stack to be within legal (200 M/SV per year) limits? Will the safety gear worn allow extra exposure? Also, are all the CB workers provided with adequate dose meters? Or is the energy company selectively providing meters to CB workers or CBWs? If so, do they go to CBWs who are exposed to high levels of radiation?

DIYer said...

The safety gear that worker is wearing is a tyvek suit, breathing filter, and hard hat. It won't slow down gamma or beta radiation, but might stop an alpha particle or two. The suit is designed to keep dust off of him, and be thrown in the waste bin at the end of the day.
In principle, the worker should be wearing a dosimeter (they used to use "film badges") that will register his exposure. Also in principle, he should be "retired" from radiation exposure after the limit is reached.
So that guy probably has a couple of minutes to do what he does, at most.

Anonymous said...

The safety gear only protects against hot particles and alpha radiation. Beta and gamma radiation and neutrons will not care about the suit and they drop off with the inverse square law (2x as far away = 1/4 of the power, 4x = 1/16...). Given that the measured radiation is thru metal pipes then it must be gamma as beta would be stopped by the pipe thickness. Not good as this stuff is leeching into the ground, the ocean or being held on site in contaminated coolant.

DD said...

re DIYer said: "The suit is designed to ... be thrown in the waste bin"

- and then what happens to the [slightly] radioactive suits, just curious?

re Anonymous said: "it must be gamma" would not be "leeching into the ground, the ocean [etc]", but of course the gamma must be coming from somewhere, and if that is water then it would be going somewhere else, just being picky, sorry. Maybe the HOT BLOB is continuing to do its predefined job of boiling water!

The news just gets worse and worse. Thanks all.

Anonymous said...

Robbie001 sez:


In the US LLW is placed in drums and buried. Some newer facilities incinerate the waste before burial some compact it. Back in the good old days they only used cardboard boxes and for some waste they still do.

In Australia they stack it warehouses.

The EPA is in the process of relaxing disposal rules so they can expand the facilities allowed to handle it.

DD said...

Maybe the next life form to evolve [after carbon is radiated away and silicon reduced to a gibbering wreck] will be radioactivity based... maybe the plutos and uros will hate each other... maybe this idea will go down like a lead balloon when nuclear decay takes its inevitable course...

Bronx Sewer Cleaning said...

Interesting post! Thanks for sharing

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