Japan’s Prime Minister Declares Nuclear Plant Stable
Dec. 16, 2011
The crippled nuclear reactors at the Fukushima Daiichi power plant have been stabilized, declared Japanese Prime Minister Yoshihiko Noda in a televised address to the nation. The magnitude-9 earthquake and subsequent tsunami that hit Japan’s main island, Honshu, on March 11 knocked out cooling systems, triggering blasts at four of the plant’s six reactors. Using seawater, workers at the plant have cooled the reactors to “cold shutdown” level, meaning the water that cools the nuclear fuel rods remains below the boiling point.
The core is the heart of a nuclear reactor. Nuclear fuel in the core of this boiling water reactor produces heat that converts water to steam. The steam runs machinery outside the reactor. A pressure vessel encloses the core and various other equipment. General Electric (World Book diagram)
For many, however, the crisis is hardly over. More than 160,000 people had to leave the area, and radiation levels in some places remain too high for people to return. A 12-mile (20-kilometer) exclusion zone remains in effect around the plant. Tokyo Electric Power Company, which operates Fukushima, acknowledges that the uranium fuel in three reactors has probably melted through their containments (holding tanks). Some nuclear experts suggest that the fuel is probably threatening ground water. The Japanese government announced earlier this week that it could take up to 40 years to fully decommission the plant and clean up surrounding areas.
The Fukushima Daiichi disaster was the world’s worst nuclear crisis since Chernobyl. The Chernobyl nuclear power plant disaster took place in Ukraine in 1986.
