RADIOACTIVE 35-SULFUR (pdf), Antra Priyadarshi and Mark H Thiemens, June 2012: [...] we were the first to recognize the nuclear core meltdown at Fukushima and estimate the neutron leakage from the core element rubble. Our ongoing measurement in samples collected from Japan shows that Fukushima was active even after 7 months of the disaster [...]
Journal of Geophysical Research: Atmospheres, 2013: An effect of [the Fukushima] disaster was secondary formation of radioactive 35S [...] when neutrons from the partially melted reactor cores activated the coolant sea water. Here we report the first measurements of 35S in sulfate aerosols and rain water collected at [...] Hokkaido, Tsukuba, Kashiwa, Fuchu, Yokohama, and Fukushima, during March-September 2011. [...] Kashiwa site [near Tokyo] shows the highest 35SO42- concentration (6.1 × 10^4 ± 200 atoms/m3) on 1 April 2011 [at] Fukushima would have been 2.8 × 10^5 atoms/m3 during the week after the earthquake [...] Even after 6 months, 35SO42- activity remains very high (9.9 × 10^4 ± 770 atoms/m3) in the marine boundary layer in the Fukushima region, which implies that the reactor core was producing radioactive sulfur.
- Kevin D. Crowley, Ph.D. Director Nuclear and Radiation Studies Board The National Academies, April 14, 2011: Mark Thiemens (UC San Diego) has detected excess sulfur-35 (in S02 and S04) that he believes was produced by the CI-35 (n,p) reaction at Fukushima after seawater cooling was initiated. This suggests that there was a source of neutrons (perhaps from a criticality event) at Fukushima after the reactors were shut down. [...]
- Crowley, April 14, 2011: [...] there was a media report that a high neutron flux had been detected at the site, presumably from a criticality event [...] That report was later dismissed for lack of corroborating evidence. Your [Mark H Thiemens] data might be useful for proving that such an event did in fact occur [...]
- John E. Kelly, Deputy Assistant Secretary for Nuclear Reactor Technologies in the Office of Nuclear Energy, April 17, 2011: [...] My guess is that the MOX fuel will have significant Pu-238 and this could create a very active source for neutron production (alpha-n). This would give a constant source (as opposed to a brief burst from criticality event). [...]
See two Fairewinds videos from 2011 about periodic nuclear chain reactions, also referred to as inadvertent criticalities, at Fukushima Daiichi: Newly released TEPCO data provides evidence of periodic chain reaction at Fukushima Unit 1 and New Data Supports Previous Fairewinds Analysis
Published: April 10th, 2014 at 10:36 am ET