Panic over at Tokai.
The cooling pump failed at the plant - just 120km from Tokyo - but an additional pump is now working and cooling the reactor, a plant spokesman says. Masao Nakano said:
Our seawater pump, powered by a diesel generator, stopped because of the tsunami and we then manually stopped one of our cooling systems.
But the other cooling systems and other pumps are working well, and temperatures of the reactor have continued to fall smoothly.
Tokai No. 2 is one of a string of nuclear power plants located along Japan's coast, which was hit by a 10-metre (33 foot) tsunami triggered by a powerful Pacific Ocean seabed earthquake on Friday.
At the worst-hit facility, the Fukushima No1 plant, crews have struggled desperately to keep cooling two reactors by pouring seawater into them, after an explosion yesterday blew off the roof and walls of No1 reactor's outer building.