Saturday, June 4, 2011

What is going on in the reactor #1 building?

About two weeks ago, Tepco sent 6 workers into the reactor to take measurements and start preliminary work for the cooling system that is slated to start by mid June.  Each worker was able to spend anywhere between 60 to 90 minutes, which would indicate exposure rates of just 2-5 milliSieverts/hr within accessed areas of the building that day.

As testimony to how fleeting progress is and how quickly things can go to pot at the plant,  NHK reports that steam, along with a biologically unacceptable amount of radiation is now present in part of the reactor 1 building, so much so that they are sending Packbots in again instead of humans.  From NHK:

Tokyo Electric Power Company inspected the inside of the No.1 reactor building on Friday with a remote-controlled robot.

TEPCO said it found that steam was rising from a crevice in the floor, and that extremely high radiation of 3,000 to 4,000 millisieverts per hour was measured around the area. The radiation is believed to be the highest detected in the air at the plant.

TEPCO says the steam is likely coming from water at a temperature of 50 degrees Celsius that has accumulated in the basement of the reactor building.

The company sees no major impact from the radiation so far on ongoing work, as it has been detected only within a limited section of the building.

The No.1 reactor is believed to have suffered a meltdown after the March 11th earthquake and tsunami.

Steam is a most unwelcome development within the reactor 1 building. With recently reported basement water concentrations of Cs-137 in the millions of Bq/cc, you can imagine what will happen if the steam persists for an extended period of time. It will permeate the entire floor and the water may evaporate away, but the residue containing isotopes remains - on the ceiling, walls, equipment - everything.

It's this sort of contamination that is extremely difficult to address, with the potential to greatly elevate readings within the entire floor.

Source: Tepco


  1. Please read this article from March 26, from an Oxford Expert. Telling people to "stop running away from radiation"

    I found his email address through a web search, here it is. I suggest that as many people as possible email him and ask him if he still feels the same way.

  2. Aloha, I updated and organized a radiation resources page on my blog. Perhaps you want to share with your readers.

  3. Steveo - Don't bother reading anything from the BBC. Check out for real news.

  4. The TEPCO No. 1 Radiation graph at seems to indicate periodic criticality. Last on period seems to be going up further instead of down. Anything can happen after meltdown, so we can only watch.