TOKYO (AP) -- A system to clean massive amounts of radioactive water at the site of Japan's nuclear disaster has been shut down hours after beginning full operations.
A spokesman for the operator of the Fukushima Dai-ichi nuclear plant said Saturday that a cartridge in the system was supposed to last a few weeks, but reached its radioactivity limit within five hours.
The spokesman says Tokyo Electric Power Co. is investigating and isn't sure when it will restart the system.
Japan's earthquake and tsunami knocked out the plant's crucial cooling systems. Water is getting contaminated as it is pumped in to cool damaged reactor cores. Now some 105,000 tons of highly radioactive water have pooled across the plant, and could overflow within weeks if action is not taken.