Partial meltdown likely underway at reactor: Japanese official

This story last updated at 11:07 EST, March 12, 2011. A partial meltdown was likely underway at a second nuclear reactor, a top Japanese official said Sunday, as authorities frantically tried to prevent a similar threat from nearby unit following a catastrophic earthquake and tsunami.

Chief Cabinet Secretary Yukio Edano said operators released slightly radioactive air from Unit 3 Sunday, while injecting water into it as an effort to reduce pressure and temperature to save the reactor from a possible meltdown.

Still, a partial meltdown in the unit is “highly possible,” he told reporters. The Globe and Mail

US Nuclear Experts Worry About Possible Japan Reactor Meltdown

Japanese officials have reassured the public, saying there is no danger of a meltdown of the reactor core. But US nuclear experts say they are worried about the possibility.

Ken Bergeron, a physicist who formerly worked for Sandia National Laboratories, says a so-called station blackout - which involves the loss of both off-site electricity and on-site backup power from diesel generators - is viewed in the nuclear industry as extremely unlikely.  But he says it happened.

"So we're in uncharted territory.  We're in the land where probability says we shouldn't be.  And we're hoping that all of the barriers to release of radioactivity will not fail," he said. Voice of America News.com

Japan weather map and potential fallout pathways

Beyond Nuclear had posted a map of projected fallout pathways with the caveats that we could not contact the supposed creators of the map (Australian Radiation Services) whose logo was in the bottom left hand corner. While the data of the weather patterns from Japan looked plausible, see the Japan Meterological Agency site, the listed radiation doses were not verifiable as of the time given on our original post and we clearly stated this. After continuing to be unable to verify this information, we have removed this fallout projection map and suggest that interested parties refer to the Japan Meteorological Agency web page for recent weather patterns (animation for the past 3-24 hours) which was the intent of our original post and which was also supplied in our original post. Also see the Stormsurfing dynamic model of trans-Pacific weather.

Associated Press reports on Unit 3 reactor crisis

Cooling systems failed at a second nuclear reactor on Japan's devastated coast Sunday, hours after an explosion at a nearby unit made leaking radiation, or even outright meltdown, the central threat to the country following a catastrophic earthquake and tsunami.

The Japanese government said radiation emanating from the plant appeared to have decreased after Saturday's blast, which produced a cloud of white smoke that obscured the complex. But the danger was grave enough that officials pumped seawater into the reactor to avoid disaster and moved 170,000 people from the area.

Japan's nuclear safety agency then reported an emergency at a second reactor unit when its cooling systems malfunctioned. Miami Herald

Update on March 12, 2011 by admin

An official from Japan's nuclear safety watchdog said earlier on Sunday that it had received a report from Japan's largest power producer at 5:10 a.m. that the facility's No. 3 reactor had completely lost its emergency cooling function.

Second reactor in trouble at Fukushima site

News reports are coming in that Unit 3 at the already critical Fukushima nuclear power plant site is in trouble. The Japanese nuclear safety agency says that the cooling system has malfunctioned at Unit 3 - this follows the explosion and possible meltdown at Unit 1. No further details are available although the power company says it is endeavoring to release pressure from the reactor after the cooling system failed. Reuters.