nuclear-news

 A new report indicates that the estimates of how much radioactivity was released remain accurate, but where it is located and concentrated are a continual source of discovery.

In fact, more than three-quarters of radioactive cesium was released as glassy microparticles formed by the meltdown, and those particles are now gathered in the nuclear exclusion zone as radioactive hot spots, according to a recent paper and presentation.

The findings were published in Environmental Science and Technology, and also scheduled for presentation at the Goldschmidt Conference of the Geochemical Society, held this week in Boston.

The cesium-134 and cesium-137 particles thrown over a wide area have now been washed down from roofs and trees and plants, where it has clustered together in the ground, according to the scientists, led by Satoshi Utsunomiya of Kyushu University.

The microparticles were distinguished from the soluble cesium by its elevated radioactivity, using a novel procedure, the investigators said.

Twenty soil samples from around the disaster area were assessed using autoradiography, similar in concept to a medical X-ray in that it would expose a photographic film or detector to image the radiation. The scientists looked at the sieved soil samples and quantitatively determined the amount of microparticles using a comparison between the photo-stimulated glow, and the radioactivity levels, they report.

Although the total amount of radiation appears accurate, its concentrations have appeared to be inaccurate, they conclude.

The initial findings were originally covered earlier this year in Laboratory Equipment. However, the findings on the concentrations and possible health impacts are new.

An independent commenter, Ken Buesseler of the Wood Hole Oceanographic Association, said in a statement released by the conference that the work has advanced the understanding of the Japanese nuclear tragedy.

“The idea of microparticles has not been ‘missed in the assessment of total cesium levels in soil after Fukushima; it has been included, although this work highlights the fraction found in cesium microparticles,” Buesseler said. “These researchers have done a fine job of developing new tools to quantify these microparticles, and that is an important story to tell.”…….https://www.laboratoryequipment.com/news/2018/08/fukushima-radiation-concentrated-particles-hot-spots