Cooling systems restored at Fukushima

Technicians have restored power to all cooling systems at the reactors of Japan's tsunami-hit Fukushima nuclear plant, the operating company said, after a blackout sparked a new crisis. Equipment in pools used to cool used fuel became fully operational from 0:12 am Wednesday (1512 GMT Tuesday), some 30 hours after the blackout, Tokyo Electric Power Co. (TEPCO) said. Used nuclear fuel becomes dangerous if its temperature is allowed to rise uncontrollably to the point where a self-sustaining critical reaction begins, causing a meltdown. The incident was a reminder of the vulnerable state of the Fukushima plant two years after the tsunami, despite the government's claim that the reactors are in "cold shutdown" and no longer releasing high levels of radiation. The latest crisis began Monday night with a brief power outage at a building on the plant's site that serves as the central command for work to contain the nuclear accident and to dismantle the reactors. The initial glitch, a suspected problem with a power switchboard, cut electricity to the cooling pools at three of the four heavily damaged reactors as well as a common pool at 7:00 pm (1000 GMT) on Monday, according to TEPCO. By Tuesday evening engineers had managed to restart cooling systems in the three affected reactor pools, TEPCO said. A separate cooling system for the common pool was restarted at 0:12 am, ending the latest problem, the company said.