Thread: History Repeating? Fears Fukushima may turn into Chernobyl

History Repeating? Fears Fukushima may turn into Chernobyl

VIDEO: http://www.youtube.com/watch?v=HLFbZ0eo1rY

The situation at the Fukushima plant is seeing comparisons drawn to the Chernobyl nuclear explosion - which was the world's worst atomic plant disaster. It happened 25 years ago in Ukraine, but the effects of the contamination are still felt today. Let's now talk to our correspondents Aleksey Yaroshevsky in Kiev and Peter Oliver in Moscow

An explosion at a Japanese nuclear power station tore down the walls of one building on Saturday as smoke poured out and Japanese officials said they feared the reactor could melt down following the failure of its cooling system in Friday's powerful earthquake and tsunami.

VIDEO: http://www.youtube.com/watch?feature=pl ... jx-JlwYtyE

Expert opinion on the situation in Japan from Christopher Simons, an Associate Professor at the International Christian University in Tokyo.

VIDEO: http://www.youtube.com/watch?feature=pl ... I2E8#at=88

http://www.redditpics.com/radiation-fal ... uak,29119/

Timeline: Power station blast
http://www.bbc.co.uk/news/science-environment-12722719



Friday, 11 March: 1446 local time (0546 GMT)

The 8.9-magnitude earthquake strikes off the coast of Honshu island at a depth of about 24km. The tremor triggers the automatic shutdown of 11 of the nation's nuclear power reactors, including reactor units 1,2 and 3 at the Fukushima Daiichi power plant. Reactor units 4, 5 and 6 were undergoing routine inspections, so were not operating.

The quake causes the power station to be cut off from the national electricity grid. The plant's operators, Tokyo Electric Power Co (Tepco), find that the diesel-powered emergency generators for units 1 and 2 are not working and notify government officials.

1600: Japan's Nuclear and Industrial Safety Agency (Nisa) sets up an emergency headquarters to gather information on potential damage to the nation's 55 nuclear reactors.

1930: Chief Cabinet Secretary Yukio Edano announces that Prime Minister Naoto Kan has declared a "nuclear emergency status". Officials reassure people that this is standard procedure in events like this and no radioactive material has been detected in the area surrounding the power station.

2100: Residents within a 3km radius of the power station are told to leave their homes, while those within a 10km radius are told to stay at home in case it is necessary to extend the evacuation area.

Following the automatic shutdown of the reactors, and the failure of emergency generators, pressure in the unit builds up as a result of the pumps in the cooling system not working properly.

The pressure is the result of the reactors residual "decay" heat causing the coolant, which is not being circulated, to evaporate.

The consequent increase in pressure in the coolant circuit can be controlled by pressure release valves, but this leads to an increase in pressure within the reactor building containment chamber.

Tepco says that the pressure inside reactor unit 1 is more than twice normal levels.

Saturday, 12 March: 0530 local time

In order to release some of the pressure inside the reactor unit, the decision is taken to vent some of the steam, which contains a small amount of radioactive material, into the air.

0819: An alarm alerts workers that the position of one control rod (used to halt the reactor) is unclear (whether it is fully inserted into the reactor or outside the reactor, allowing it to continue generating heat)

1009: Tepco confirms it has released a small amount of vapour into the atmosphere to reduce pressure in reactor unit 1.

1043: Control rod alarm stops, and all rods are confirmed as being fully inserted.

1058: In order to release some of pressure inside reactor unit 2, some steam was vented into the air. Again, this contains a small amount of radioactive material.

1530: TV cameras capture a massive explosion at the power station. The pictures appear to show that the outer structure of one of four buildings at the plant has collapsed. Tokyo Electric Power Co says four workers have been injured in the blast.

2000: Uncertainty surrounds what was the actual cause of the explosion, and what damaged was caused by the blast.

Chief Cabinet Secretary Yukio Edano confirms that the concrete building surrounding the steel reactor container has collapsed as a result of the blast, but the steel containment chamber itself had not been damaged.