[ RadSafe ] New Meltdown Byproduct Found Far From Fukushima Daiichi
peter.bossew at reflex.at
Sat Feb 6 11:14:43 CST 2016
Both is correct.
How the radio-caesium containg spheres were generated has not yet been
clarified to my knowledge.
Black dust: typical results of radioecol. concentration processes, quite
common. Large amounts of similar blackish matter can be found on Alpine
glaciers (in that context called cryoconite), with partly very high
concentrations of Chernobyl and even global fallout.
In Japan, I used such samples to identify Pu from Fukushima quite far away
from the NPP. If I remember well, the fathest distance from the NPP where
such matter has been found, is the Yokohama area S of Tokyo.
"The International Radiation Protection \(Health Physics\) Mailing List"
<radsafe at health.phys.iit.edu> schreibt:
>This looked like it might be solid scientific article, then I noted
>that it was discussed on RADSAFE three years ago, so it is hardly new
>and I found no actual scientific journal article. It also has been
>put out by Gundersen's Faire Winds so I wonder just how solid the
>---------- Forwarded message ----------
>New Meltdown Byproduct Found Far From Fukushima Daiichi
>by dunrenard (French anti-nuclear activist who never seems to use his
>real name - typical of activists - never stand behind what they claim
>to be true because someone could disprove it)
>Another type of material has been found by researchers that is tied to
>the meltdowns at Fukushima Daiichi. We have reported extensively over
>the years on the finding of “black stuff” around mainland Japan. This
>is a highly radioactive black sand like material that had gathered in
>gutters and roads as far away as Tokyo. Analysis of materials of that
>type has linked them to the meltdowns inside the reactors at Fukushima
>Daiichi. This new finding is also linked directly to the reactor
>Photo of black sand substances found in Namie, from research paper by
>Marco Kaltofan. Photo credit Marco Kaltofan.
>Researchers in Japan found new materials they described as tiny
>spherical glass particle that was highly radioactive. These glass
>particles are structurally quite different from the “black stuff” but
>they also bear a link back to the reactor meltdowns. A glass particle
>labeled NWC-1 was collected from Nihonmatsu in 2011 after the initial
>disaster. Nihonmatsu is roughly 40-45 km directly west of Fukushima
>Daiichi. The town area sits south of Fukushima City and north of
>Koriyama. This area is well outside the evacuation zone and is
>currently occupied without restriction.
>These glass particles include high levels of radioactive cesium.
>Researchers found that the radioactivity was highest in the center of
>the particle, indicating the cesium was incorporated into the glass
>particle during the molten phase of the meltdown. The glass particle
>also contains materials that indicate it includes either concrete from
>the containment vessel or seawater that was injected. This is
>significant as it shows this material was formed after the melted fuel
>burned through the reactor vessel and had begun burning the
>containment vessel concrete floor, or it formed after seawater was
>injected. The seawater injections were fairly late in the meltdown
>progression and newer research shows all or most of that water flowed
>the wrong direction and didn’t make it to the reactor vessels. The
>timing of the creation of these glass spheres would be between the
>time of the first reactor vessel failure and the start of seawater
>injection then thereafter. This may help in the future to identify the
>specific reactor and event that may have created these spheres.
>Photo of the glass sphere from Nihonmatsu, from the Yamaguchi et al study.
>Cross section of the NWC-1 glass sphere from Nihonmatsu, photo credit
>Yamaguchi et al.
>The location of the found particle in Nihonmatsu is unexpected. A
>second glass sphere was found on a cedar leaf in Fukushima, specific
>area not mentioned. Nihonmatsu is directly west of the plant and not
>in the documented plume paths that developed north-west and south of
>the disaster site. This appears to indicate that materials from the
>reactors themselves were transported far further than initially
>claimed. These glass particles are small enough in size to potentially
>be inhaled. Right now researchers do not know the extent or geographic
>spread of this material. It does show that direct materials from
>inside the reactors did leave the buildings and were distributed over
>a long distance. Due to the high radioactivity within these glass
>spheres they could pose a significant health risk.
>We put together a rough comparison of the properties of the two
>reactor meltdown byproducts. This is not a definitive list. Please
>refer to the original studies for further information.
>Yamaguchi, N. et al.
>Internal structure of cesium-bearing radioactive microparticles
>released from Fukushima nuclear power plant.
>Sci. Rep. 6, 20548; doi: 10.1038/srep20548 (2016).
>Black Stuff Analysis:
>Radiological Analysis of Namie Street Dust
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