20 March 2011
UPDATE 1: 2.56pm GMT Units 5 and 6 in cold shutdown, tsunami heights
UPDATE 2: 3.30pm GMT IAEA graph of fuel pond temperatures

Workers on site have succeeded in increasing the stability of the Fukushima Daiichi reactors, with units 5 and 6 now in cold shutdown. Pressure built up within unit 3 but a more significant venting does not seem necessary now.

External power has now been connected to unit 5 and 6, allowing them to use their residual heat removal systems and transfer heat to the sea. This has been used to cool the fuel ponds and bring the units to cold shutdown status, meaning that water in the reactor system is at less than 100ºC.