This video from Canada says about itself:
13 October 2015
New Meltdown Byproduct Found Far From Fukushima Daiichi
February 4th, 2016
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 meltdowns.
From Nature.com about this:
Internal structure of cesium-bearing radioactive microparticles released from Fukushima nuclear power plant
3 February 2016
Microparticles containing substantial amounts of radiocesium collected from the ground in Fukushima were investigated mainly by transmission electron microscopy (TEM) and X-ray microanalysis with scanning TEM (STEM). Particles of around 2 μm in diameter are basically silicate glass containing Fe and Zn as transition metals, Cs, Rb and K as alkali ions, and Sn as substantial elements. These elements are homogeneously distributed in the glass except Cs which has a concentration gradient, increasing from center to surface.
Nano-sized crystallites such as copper- zinc- and molybdenum sulfide, and silver telluride were found inside the microparticles, which probably resulted from the segregation of the silicate and sulfide (telluride) during molten-stage. An alkali-depleted layer of ca. 0.2 μm thick exists at the outer side of the particle collected from cedar leaves 8 months after the nuclear accident, suggesting gradual leaching of radiocesium from the microparticles in the natural environment.
Defiant to the end, last of Group of Six anti-nuclear scientists about to retire — The Asahi Shimbun: here.
Group to monitor trial of former Tepco executives to clarify truth about Fukushima disaster — The Asahi Shimbun: here.