My thought go out to all those in Japan in the continuing disaster which seems to be going on after the earth quake struck last week.
I didn’t understand what is happening in the plant from the media reports I heard on the radio… but the situation seems to still be developing.
Can anyone explain to me why it is not possible to cool a nuclear power station with a passive system like the ones used to move the water around a central heating system? Is it more expensive or less efficient? Are there cooling systems which don’t rely on water?
Information from Wikipedia page Fukushima I Nuclear Power Plant:
The units are all GE designed, reactors 1, 2, and 6 were supplied by General Electric, those for Units 3 and 5 by Toshiba, and Unit 4 by Hitachi.
On 11 March 2011 an earthquake categorised as 9.0 MW on the moment magnitude scale occurred at 14:46 Japan Standard Time (JST) off the northeast coast of Japan. This led to cooling problems in reactors 1, 2 and 3. Over 170,000 people were evacuated after officials voiced the possibility of a meltdown. The external structure of Units 1, 2, and 3 collapsed after hydrogen explosions. The containment building of Unit 1 and 3 remained intact, but Unit 2 was feared damaged. On 15 March 2011, the Unit 4 fuel pond caught fire, increasing radiation levels and prompting more evacuations.
Reactors 1, 2 and 3 have been filled with seawater and are likely to be decommissioned, since it is not cost effective to decontaminate.