Cobalt 58 was detected in Gunma, half-life is 71days, “Possibile recriticality around after April”

Cobalt 58 was detected from the black substance in Gunma. (cf. http://fukushima-diary.com/2012/08/bl...1346-bqkg/)

Co-58 is produced from neutron ray, the half-life is only 71 days.

The video was taken by Mr. Sakagami, an engineer of radiation measurement equipment.

It was caught on the video by portable spectrum of Bicron, but he added this comment that he always saw the “peak” on the spectrum by other instruments.

Cs-137 was also detected in addition to Co-58.

About this measurement of Co-58, Mr. Sakagami also commented like this on 7/24/2012,

コバルト58の半減期は　70日ですよね

それが　先月見つかったのは　福島の第一は　数ヶ月前に　臨界で危険な状態になっていた　証拠です



<Translate>

The half-life of Co-58 is about 70 days. I measured it last month, which means Fukushima plant was having recriticality a few months ago.

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Original article with photo and video: http://fukushima-diary.com/2012/08/co...ter-april/