Fukushima Nuclear Disaster 5 Years On: Water, Water Everywhere (Part I)
March 11, 2011 is a day most of us living in Japan at the time will remember for the rest of our lives.
At 2.46 p.m. a magnitude-9 earthquake struck 72km (45 miles) off the northeast coast of Japan, causing local damage as well as high-rise buildings 770km from the epicenter down in Osaka to sway for minutes. But the real destruction occurred an hour later when a tsunami came roaring in and devastated much of the coastline, sweeping inland as far as10km and reaching a run-up height of 39 meters (128 feet) in some areas.
The third whammy only became known that night, after it was announced that the tsunami had knocked out the electric power and backup generators at Tokyo Electric Power Company’s (TEPCO’s) Fukushima Daiichi Nuclear Power Plant. Afraid of a meltdown, the government ordered residents in the area to evacuate.
In the days following, there were hydrogen explosions in some of the reactor buildings, and much later we learnt three of the six reactors in the plant had indeed suffered partial meltdowns due to cooling system failures.
Now, on the fifth anniversary of what is known here as the Great East Japan Earthquake, how much progress has TEPCO and the government made in dealing with what was fundamentally a man-made disaster?
The answer is they continue to face the same four huge challenges they grappled with in 2011: dealing with contaminated water that has grown into a million-ton headache; locating and somehow retrieving the molten fuel debris; removing spent fuel rods from the damaged reactor storage pools; and disposing of millions of cubic meters of radioactive waste.
Most evident of these challenges is the contaminated water. Cooling water must be continuously circulated through the damaged reactors Units 1, 2 and 3, where nuclear fuel has melted through at least the inner containment vessels. Consequently, the cooling water injected into the reactor becomes contaminated and finds its way down into the turbine basements adjacent to each reactor; there, it mixes with incoming ground water to greatly compound the problem.
Forrás: http://www.forbes.com
