The September 30 sample measured only 0.38 µSv/hr, but contained iodine-131 at 179 Bq/kg (and radioactive cesium at 8,434 Bq/kg).
There is also a report of another discovery of iodine-131, this time south of Tokyo in Kawasaki. 32 Bq/kg of Iodine-131 was measured in sewage sludge.
The half life of iodine-131 is eight days.
These findings “may prove Fukushima went back to recriticality after that again” writes Mochizuki.
Read More: Breaking News: Fukushima recriticality again
Published: October 18th, 2011 at 1:41 pm ET
- “Fukushima in recriticality”? — Iodine-131 detected in 4 locations: Tokyo, Iwate, Nagano, Niigata (CHARTS) September 9, 2011
- Iodine-131 detected in Tokyo snow on Jan. 20 January 20, 2012
- Recriticality? Iodine-131 detected in rice samples from late October October 30, 2011
- Iodine-131 detected in Tokyo at multiple locations during November — 350 bq/kg at Kita garbage facility December 12, 2011
- Radioactive iodine found in Gunma at 3 sewage plants — “Possibility of recriticality again” December 12, 2011