Preprint / Version 1

On residual 137Cs on shallow rugged reefs lying inshore of Fukushima: Part 1

Levels, distribution, and flux of radiations

##article.authors##

  • Fumie Suzuki EcoStudies Association
  • Hideo Ohashi EcoStudies Association
  • Ken-ichi Nogami EcoStudies Association
  • Hiromi Shibata EcoStudies Association
  • Hisayuki Arakawa Faculty of Marine Resouces and Environment, Tokyo University of Marine Science and Technology
  • Kentaro Umeda Department of Electric and Electronic Engineering, Tohoku Institute of Technology
  • Teiji Kobayasi Tohoku University
  • Nobuhiro Shiotani EcoStudies Association

DOI:

https://doi.org/10.51094/jxiv.599

Keywords:

Fukushima Daiichi Nuclear Power Plant, Levels of 137Cs on rugged reefs, Simulation of transport of 662 keV gamma rays, Scalar flux of low energy gamma rays

Abstract

Levels of residual 137Cs on reefs lying inshore of Fukushima were measured with the use of a newly improved underwater CsI(Tl) gamma-ray spectrometer. The levels varied from point to point, ranging from 1.0×104 Bq/m2 to 9.9×104 Bq/m2. All the measured spectra showed the presence of significant amounts of flux of gamma rays of energies less than 662 keV. With the use of an empirically determined spectrum of the Compton continuum inevitably created in the detector, a true spectrum of low energy gamma rays on and near the interface between contaminated rock surface and seawater was obtained. Analyses of transport of 662 keV gamma rays confirmed that those low energy gamma rays were derived from the multiple Compton scattering of 662 keV gamma rays emitted from residual 137Cs on the interface between the contaminated rock surface and seawater. A simple dose rate estimation is carried out for two ICRU tissue substitutes placed on the interface.

Conflicts of Interest Disclosure

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

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Posted


Submitted: 2024-01-14 15:50:17 UTC

Published: 2024-01-20 00:52:44 UTC
Section
Earth science & Astronomy