Month: April 2011

Bloomberg reports:

The risk to workers might be greater than previously thought because melted fuel in the No. 1 reactor building may be causing isolated, uncontrolled nuclear chain reactions, Denis Flory, nuclear safety director for the International Atomic Energy Agency, said at a press conference in Vienna.

Time Magazine eco blog:

On March 23, Dr. Ferenc Dalnoki-Veress, a Research Scientist at the Monterey Institute of International Studies saw a report by Kyodo news agency that caught his eye. It reported that Tokyo Electric Power Company (TEPCO) had observed a neutron beam about 1.5 km away from the plant.  Bursts of neutrons in large quantities can only come from fission so Dalnoki-Veress, a physicist, was faced with an alarming possibility: had portions of one of Fukushima’s reactors gone critical?

To nuclear workers, there are few events more fearful than a criticality accident. In such a scenario, the fissile material in a reactor core–be it enriched uranium or plutonium–undergoes a spontaneous chain reaction, releasing a flash of aurora-blue light and a surge of neutron radiation; the gamma rays, neutrons and radioactive fission products emitted during criticality are highly dangerous to humans. Criticality occurs so rapidly–within a few fractions of a second–and so unpredictably that it can suddenly kill workers without warning. There have been 60 criticality incidents worldwide since 1945. The most recent occurred in Japan in 1999, at an experimental reactor in Tokai, when a beam of neutrons killed two workers, hospitalized dozens of emergency workers and nearby residents, and forced hundreds of thousands to remain indoors for 24 hours.

UPDATED: The IAEA has said that the Fukushima nuclear power plant may have achieved re-criticality.  “There is no final assessment,” IAEA nuclear safety director Denis Flory said at a press conference on Wednesday, according to Bloomberg News. “This may happen locally and possibly increase the releases.”

Read on below the fold to see what purports to be a photo of the “blue flash”.

It’s an animated gif that is too annoying to post on the main page.

Continue reading “Is this the Blue Flash?: Re-criticality may be in progress – IAEA”

A blue light can be an indication that fission is proceeding at the facility.

In the video below the fold, an example of what observers might be seeing at Fukushima:

Continue reading “Blue Glow seen at Plant: Fission in Progress?”

Anderson Cooper on the distortions, lies, “message control”, and misinformation from TEPCO. Outrage rising in Japan.

Arne Gunderson is an expert with experience as a nuclear industry executive. His updates, he said, will be coming every other day. This is from thursday, and I’ll be looking for the next one as soon as it’s available.

Meanwhile, Reuters is reporting that a leak has been discovered draining high level radioactive material directly into the Pacific ocean.

April 2 (Reuters) – The operator of Japan’s quake-stricken nuclear plant said on Saturday it had found radioactive water leaking into the sea from a cracked concrete pit at its No.2 reactor in Fukushima.

Tokyo Electric Power Co (TEPCO) officials said it was possible that the crack may be the source of recent radiation contamination in the sea off the northeast coast.

The radiation in the pit measured 1,000 millisieverts per hour. It was not clear whether the water had come from the reactor itself nor how much has been leaking from the pit into the sea.

Hidehiko Nishiyama, deputy director-general of the Nuclear and Industrial Safety Agency, told a separate news conference that TEPCO was planning to pour concrete into the pit to seal the crack.