Critical mass, Nature Magazine, Dec. 15, 2011:
More than nine months after the nuclear-reactor disaster at Fukushima, fundamental questions about what happened remain unanswered. Without answers to these questions, Japan, and the rest of the world, is in the dark on what went wrong, what must be done now, and how to avoid similar accidents in future.
A Comment in this week’s issue summarizes these concerns (see page 313). For the Japanese public, one of the most troubling things about the article should be the identity of its authors: two ruling party politicians, including a former prime minister. Surely they should be able to get some answers? [...]
Unfortunately the issue is not available online, but Yomiuri summarizes the contents.
Hatoyama: Nationalize Fukushima N-plant, Yomiuri Shimbun, Dec. 16, 2011 (Emphasis Added):
In the Nature article, former Prime Minister Yukio Hatoyama:
- Criticizes Tokyo Electric Power Co., the operator of the crippled plant, for disclosing only limited information to Diet committees
- Hints at the possibility of recriticality at the plant
- Says there is still much about the crisis that needs clarification, including the state of the molten fuel within the nuclear reactors
Chlorine Detected… “Released During Recriticality”
Hatoyama also says that he and [Tomoyuki Taira, member of the House of Representatives] obtained data on samples of contaminated water TEPCO obtained from the basement of the plant’s No. 1 reactor and asked an outside research institute to reanalyze them.
Results showed that radionuclide chlorine 38, one of the isotopes released during recriticality, “was indeed present,” he claims.
TEPCO reported at one point that it found chlorine 38 in the sampled water, but the utility later retracted that statement, saying there was a mistake in the analysis.
More from Yomiuri
Only by bringing the Fukushima No. 1 nuclear power plant into government hands can scientists thoroughly discover what caused the nuclear crisis, former Prime Minister Yukio Hatoyama says in an article published in the Dec. 15 issue of the British science journal Nature. [...]
Hatoyama said the Fukushima plant “must be nationalized so that information can be gathered openly.” [...]
It is extremely rare for a major science journal to carry an article written by a former prime minister as a cover story, according to an official of Nature Japan.
More information on past Chlorine-38 reports at Fukushima
- “If chlorine-38 was detected that can only mean ‘recriticality’.” -Professor Koide, Kyoto University’s Research Reactor Institute
- “Radioactive chlorine found March 25 in the Unit 1 turbine building suggests chain reactions continued after the reactor shut down, physicist Ferenc Dalnoki-Veress of the James Martin Center for Nonproliferation Studies in Monterey, California, wrote” -Source
- “In order to form CL-38 [...] Dalnoki-Verress did some calculations and came to the conclusion [there] was the presence of transient criticalities in pockets of melted fuel in the reactor core” -Source
h/t Anonymous tip
Watch nuclear engineer Arnie Gundersen discuss chlorine on April 3 here
Published: December 16th, 2011 at 5:33 am ET
- Professor at Kyoto University’s nuclear institute changes mind: I’ve started to think fission has happened again… re-criticality April 6, 2011
- “Recriticality? Possibility of recriticality?! IAEA report: a meltdown at Fukushima unit 3?” (JAPAN TV) May 19, 2011
- UPI: Active geological fault lies directly beneath Japan reactor — Yomiuri: “Extremely uncertain” if it can be reactivated April 25, 2012
- Bloomberg: “Nuclear reaction threat” as temperature rises — Head of Japan nuke institute: “Nobody is sure about the location of melted fuel — A similar incident will probably occur again” February 7, 2012
- Radioactive iodine found in Gunma at 3 sewage plants — “Possibility of recriticality again” December 12, 2011