After the catastrophic earthquake (Japan's Meteorological Agency revised the magnitude to 9.0 on the Richter Scale) on March 11, the condition of the nuclear plants near the quake-struck area has become the focus of the international community.
On March 14, at 11:01 am, a hydrogen explosion occurred at Unit 3 of the Fukushima Daiichi Nuclear Plant. According to the International Atomic Energy Agency, the control room of Unit 3 remains operational. However, there is now fear that reactor N. 3 may also burst.
Two days ago, an explosion occurred at reactor N.1 of the same plant. Four workers were injured while attempting to fix the situation at the facility; three more reported subsequent injuries from other on-site incidents. In addition, one worker was exposed to higher-than-normal radiation levels. The International Atomic Energy Agency (IAEA) posted on its website:
The Japanese authorities have classified the event at Fukushima Daiichi Unit 1 as a level 4 “Accident with Local Consequences“ on the International Nuclear and Radiological Event Scale (INES). The INES scale is used to promptly and consistently communicate to the public the safety significance of events associated with sources of radiation. The scale runs from 0 (deviation) to 7 (major accident). - IAEA Japan Earthquake Update (12 March 2011, 21:10 CET)
At least 190 people have been exposed to the radiation released from the Fukushima Daiichi Nuclear Plant explosion, according to Asahi News.
An article in the Italian newspaper, La Repubblica, quotes French experts who confirmed that the white cloud that was released from the explosion at Fukushima Daiichi, charged with iodine-131 and caesium-137, released a dangerous quantity of radioactive material in the air.
On 13 March, the French embassy in Tokyo warned its nationals to leave the Tokyo area “for a few days,” due to the threat posed by the Fukushima nuclear plant and potential risks of more earthquakes throughout the archipelago. A day before, the Hong Kong government issued a Black Outbound Travel Alert (OTA), urging people to avoid traveling to Fukushima prefecture. The U.S. embassy has also called for its citizens to evacuate Tokyo, and according to Yonhap News, South Korea has issued a Level 2 advisory for areas around the plant and a Level 1 advisory for Tokyo and Chiba.
Chief Cabinet Secretary Edano Yukio said there was a “low possibility“ of a dangerous radiation leak, adding that water was still being pumped into the reactor to cool it down. TEPCO, the operator of Fukushima Daiichi Nuclear Plant, stressed that although the nuclear plant framework and the reactors had burst, the core was still intact.
However, the situation is still precarious. A Yomiuri News report said that after the 9.0 earthquake struck Japan, 11 nuclear reactors of two operators, TEPCO and Tohoku Electric Power, performed automatic shut down due to strong shakes. And according to Japan’s Nuclear and Industrial Safety Agency (NISA) and both operators, only No. 3 reactor of Fukushima Daini (i.e. “the second”) Nuclear Power and No. 1 and No. 3 reactors of Onagawa Nuclear Power Plant achieved stable “cold shutdown” state, which implies that the remaining eight reactors require continuous cooling. This will require careful handling.
Some Japanese experts are not optimistic about the current situation. Aritomi Masanori, director of the Research Laboratory for Nuclear Reactors in Tokyo Institute of Technology, believed that the No. 3 reactor is in a more threatening state than that of No. 1 reactor. He said that the water level inside the pressure vessel has not increased after the operator started pumping seawater as a coolant. This could signify that the steel reactor container might have been damaged, and the black smoke during explosion could potentially contain radioactive material.
As per the explosion of No.1 reactor on 11 March, before the first explosion occurred (15:36 Japan time), as much as 170 cm of the fuel rods were reportedly exposed above the water from 10:04 to 15:28, according to information from the Office of Japan’s Prime Minister.
In view of the scarce information available, Goto Masashi, a former Toshiba engineer who specialized in designing containment vessels of reactors, warned that the cooling system was the core of the problem. He repeatedly urged Japanese government officials to disclose more information regarding the reactors, such as temperature inside the vessel.
Goto pointed out in a press conference on March 13 that using seawater as coolant is not appropriate given the design of the reactors; rather, a high power pump is required. The sudden increase in pressure in addition to the high temperature within the vessel could lead to severely adverse consequences.
Goto said that the out-datedness of these facilities was one of the several causes of the explosion, and admitted that the magnitude of this earthquake had exceeded all precautionary assumptions that had been postulated during their design. The pressure in the containment vessel rose to about 1.5 to 2 times the level it could sustain, he added. Toshiba supplied reactor units 3 and 5 of Fukushima Daiichi Reactor, while General Motors furnished reactor unit 1.
The Fukushima disaster has prompted many European countries to scrutinize domestic nuclear safety. German Chancellor Angela Merkel staged a crisis meeting with key ministers on Saturday, before the second explosion occurred, wherein she emphasized the importance of nuclear safety within Germany and within the EU at large, AFP reported.
As if mother nature had not punished the Land of the Rising Sun enough, after 52 years of inactivity, the Shinmoedake vulcano erupted in the southern island of Kyushu on March 13, covering the sky with a blanket of soot.