Professor finds ‘black dust’ at 4 locations in Koriyama, up to 9 microSv/h — Only measuring gamma radiation

Published: April 10th, 2012 at 8:57 pm ET


Title: Professor Yukio Hayakawa Takes a “Radioactive Walk” In a Park in Koriyama City, Fukushima, Finds 9 Microsieverts/Hr “Black Dust”
Source: EXSKF
Date: April 10, 2012

Professor Hayakawa went to Koriyama City in Fukushima Prefecture and walked in Kaiseiyama Park right near the City Hall. […]

[…] professor is armed only with his personal survey meter that only measures gamma ray […]

He took the measurement of “black dust” at 4 locations:

  • 3.533 microsieverts/hr
  • 9.103 microsieverts/hr
  • 7.291 microsieverts/hr
  • 6.331 microsieverts/hr (in the City Hall parking lot)

Read the report here

Published: April 10th, 2012 at 8:57 pm ET


Related Posts

  1. Report: Radioactive “black dust” in Fukushima City, 60km from meltdowns — “It is not just in Minami Soma City” (PHOTO) March 17, 2012
  2. OPCOM emergency survey of more black dust finds alpha radiation of 45 microSv/h — Measured at public housing project in Minami Soma February 18, 2012
  3. Professor measuring contamination warns police of high radiation levels in area — Commander responds “Slander!” June 12, 2012
  4. UPDATE: Original mystery black substance was never tested — Much more radioactive than official’s black dust — Detector shows 95,880 cpm — Up to 60,000 cpm in beta — New alpha info February 17, 2012
  5. 42.85 microSv/h detected in Koriyama — 15.5 microSv/h outside NHK broadcasting station (VIDEO) December 23, 2011

11 comments to Professor finds ‘black dust’ at 4 locations in Koriyama, up to 9 microSv/h — Only measuring gamma radiation

  • StillJill StillJill

    Would someone please give us 'simpletons' an idea how high these numbers are? Gosh I need to DECIDE to learn this stuff!


    • fireguyjeff fireguyjeff

      Here you go


      Maximum allowable exposure for U.S. radiation workers: 50 mSv per year.

      …the average annual U.S. radiation dose of 6.20 mSv.
      Half of that is attributed to natural sources, the other half man made (industrial/medical)

      Above background levels of radiation exposure, the NRC requires that its licensees limit maximum radiation exposure to individual members of the public to 1mSv per year.

      So 3.1mSv per year is a good start for natural/background exposure.

      So here is the condensed math from this story headline.

      usV/hr mSv/year
      3.53 30.95
      9.1 79.74
      7.29 63.87
      6.33 55.46

      (uSv/hr x 24 x 365 = mSv/year)

      Best case scenario is 10x background
      Worst case measurement is 25.7x background.

      Not exactly a comfortable umber to me.
      In my world, a number that the NRC allows is one that was skewed for the nuclear industry.
      For myself, I take the NRC value and divide it by at least 100 in order to come up with a number that has a chance of making sense. Just my personal take on it. They are not to be trusted, except to screw all of us in the arrangement.

      I am more than open to correction if any one sees any error in my math here.

      • fireguyjeff fireguyjeff

        formatting gagged!!!!
        Let's try this


  • many moons

    I wish that somebody with some scientific equiptment/knowledge or background could let Japan know what the black dust is so they can call it what it is and not the pathetic black dust/mysterious black powder name-once and for all! When I was in grade school science class we were given substances and by appling what we learned we were able to discover what the substance was….there are ways to test things to find out animal, vegtable, mineral…PLEASE is there anyone in Japan who can tell us for God sake what is the black powder…if it is the cyanobacteria…then call it that!!!!

    • Misitu

      – is the yellow pollen related to uranium oxide(s)?
      – the black stuff on all the items I've read here and on related forums is "vegetable matter" "alpha emitting" and identified as [containing(?)] cyanobacteria. That's the best we hear at present until someone inside feels guilty and starts leaking more detail. For me it's a bacterial mutation using some of the energy from the hot material for growth: it's probably not viable long term, hence the generation of dust from dead bacterial matter = is my guess.

      It is one big worry nobody COULD HAVE foreseen (unlike what happens if you forget to maintain pipework integrity at a coastal NPP build on an active seismic zone).

      There are LOTS of worries now. And I can see that people are beginning to get worried. This is going to cause a change in the "Disaster Response Adaptation Strategy". This change is about a year too late. Sometimes it's not possible to reverse a trend.

      I don't think anybody is going to "out" the yellow pollen as a Uranium compound. That's a bit scary. Although my take on the Scary versus True battle has always been that True wins.



  • sonnen.blum.239 sonnen.blum.239

    doubtful that it is blue green algae poisoning. that is water borne, water bred. it may be ash from the incineration of waste most of which may well be radioactive from all assumptions on what the Japanese are burning.

    yellow powder has been called fukushima pollen…a misnomer at best. I have plenty yellow cake around the pool and pool cover from the winter and this spring, and it is three to four times background radiation. Do not inhale this…internal contamination is deadly. Pollen is no longer pollen.

  • Is it here, You folks on the west may want to start lQQking !

  • TheBigPicture TheBigPicture

    Highly radioactive powder, spread around the ground. Not good.