This interactive graphic tracks events, both reactor by reactor, and through a timeline, at Tokyo Electric Power Company’s (Tepco) Fukushima Daiichi atomic energy plant as engineers work to prevent a nuclear disaster.
Difficulties first emerged on March 11 at reactor No 1 when the Japanese government declared a “nuclear emergency status”, but subsequently all six reactors have experienced problems of some variety.
On Sunday April 17, Tepco warned that it could take nine months to resolve the crisis at the plant.
The company said it would take three months to stabilise the cooling system for overheated reactors and spent fuel pools at the plant. Another three to six months would be needed to achieve a “cold shutdown”, it added.
A “cold shutdown” means the water inside a reactor is below 100 degrees centigrade at normal atmospheric pressure – conditions that indicate the reactor’s radioactive uranium fuel is safe from heating up again.
Once a “cold shutdown” has been achieved, the long decommissioning effort can begin. The whole process is expected to take at least a decade.
Graphic last updated April 21 2011.
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