Tokyo Electric Power

The International Atomic Energy Agency has been providing updates on the damaged Japanese nuclear plants on its Facebook page. "Japan's Nuclear and Industrial Safety Agency has informed the IAEA's Incident and Emergency Centre that there has been an explosion at the Unit 1 reactor at the Fukushima Daiichi plant, and that they are assessing the condition of the reactor core," the latest statement said. "The explosion was reported to NISA by the plant operator, TEPCO, at 0730 CET. Further details were not immediately available.

President Obama on Friday offered earthquake-ravaged Japan any assistance needed to cope with the massive 8.9 temblor that has devastated the Asian nation, including technical aid to cope with a damaged nuclear power plant that has led to the evacuation of thousands for fear of a radiation leakage. U.S. Air Force planes have already delivered coolant to the damaged nuclear power plant in Fukushima prefecture, Secretary of State Hillary Rodham Clinton announced. Photos: Scenes from the earthquake No radiation leakage has been detected, but pressure inside a reactor at the Fukushima-Daiichi plant rose after the cooling system was knocked out by the quake Friday afternoon Japan time, according to the plant's parent company, Tokyo Electric Power.

Another nuclear reactor at the Fukushima No. 1 facility in Japan has lost its emergency cooling capacity, according to the Associated Press, bringing to three the number of reactors at that facility to fall prey to Friday's magnitude 8.9 earthquake and tsunami. Added to failure of three reactors at Fukushima No. 2, the count is now six overall. So far, the only reactor that seems to pose an immediate risk of widespread danger is one of the two shut-down reactors at Fukushima No. 1, also known as Fukushima Daiichi, which was disabled by an explosion overnight that destroyed the building housing the reactor and the backup cooling system.

Japanese officials have begun pumping seawater into a second nuclear reactor at the Fukushima No. 1 power plant 140 miles north of Tokyo to cool the reactor core in a last-ditch effort to stave off a core meltdown. The action indicates that the reactor's normal backup cooling system has failed and is no longer able to supply fresh water to the core. Officials at Tokyo Electric Power Co., which owns the plant, have been struggling to keep six shut-down nuclear reactors cooled because seawater from the tsunami that followed Friday's magnitude 9.0 earthquake damaged the diesel generators that power the circulating pumps.

[Update 12:47 a.m.] Tokyo's utility company says black smoke has been seen emerging from Unit 3 of the crippled nuclear plant in northeastern Japan, prompting a new evacuation of the complex. Officials with Tokyo Electric Power Co. said Wednesday that workers from the entire Fukushima Dai-ichi plant have been temporarily evacuated. _________________ Control room lights were on and electronic thermometers were functioning Wednesday at several of Japan's stricken nuclear reactors, marking small but potentially critical steps toward controlling overheated fuel that has been spewing radiation for more than a week.

Japanese nuclear regulatory officials Tuesday raised the severity rating at the earthquake- and tsunami-damaged Fukushima Daiichi power plant to the highest level by international standards, equaling the 1986 Chernobyl meltdown in the former Soviet Union. The country's Nuclear and Industrial Safety Agency announced that because of the amount of radioactive material released from the plant after the magnitude 9 earthquake a month ago, the rating would be changed to level 7, a "major accident" on the International Atomic Energy Agency's scale, up from a level 5, an "accident with wider consequences.

The federal government's radiation alert network in California is not fully functional, leaving the stretch of coast between Los Angeles and San Francisco without the crucial real-time warning system in the event of a nuclear emergency. Six of the Environmental Protection Agency's 12 California sensors ? including the three closest to the Diablo Canyon nuclear power plant near San Luis Obispo ? are sending data with "anomalies" to the agency's laboratory in Montgomery, Ala., said Mike Bandrowski, manager of the EPA's radiation program.

Radiation has been detected in seawater in areas surrounding the earthquake and tsunami-ravaged Fukushima nuclear plant in northeastern Japan, creating one more cause for concern after radiation was found in food items and tap water. Officials stressed that the levels -- which they said would have minuscule impact on the human body even if the seawater were ingested daily over a year -- were not cause for alarm. Tokyo Electric Power Company, which owns the plant, said it detected radioactive iodine-131 more than 125 times higher than the legal limit in a sample of ocean water found about 0.2 miles south of the Fukushima Daiichi plant on Monday, Kyodo News Agency reported.

For nearly four weeks, Japanese emergency crews have been spraying water on the damaged Fukushima Daiichi nuclear reactors, a desperate attempt to avert the calamity of a full meltdown. Now, that improvised solution to one nuclear nightmare is spawning another: what to do with the millions of gallons of water that has become highly radioactive as it washes through the plant. The water being used to try to cool the reactors and the dangerous spent fuel rods is leaking through fissures inside the plant, seeping down through tunnels and passageways to the lowest levels, where it is accumulating into a sea of lethal waste.

The fuel rods at a third nuclear reactor at the Fukushima No. 1 nuclear power plant have been fully exposed to air for short periods of time and at least partially exposed for more than three hours, allowing them to heat up and sharply raising the risk of a meltdown, according to officials of the Tokyo Electric Power Co., which owns the plant. The cooling problems at reactor No. 2 represent the most serious development in the ongoing problems at the nuclear power plant to date, according to nuclear specialist Edwin Lyman of the Union of Concerned Scientists.