Tokyo Electric Power Co said Wednesday it had suspendeda radioactive water treatment system at the Fukushima Daiichi nuclearplant due to deteriorating performance, dpa reported.The operator found Tuesday that one of the three lines in the cleanupsystem did not eliminate radioactive material sufficiently.Tokyo Electric halted all three lines called the Advanced LiquidProcessing System (ALPS), but it did not detect any defects in the other two, said Akitsuka Kobayashi, a company spokesman.The operator has been investigating the problem since Tuesday,Kobayashi said.The system is regarded as a key facility to deal with the massiveamounts of radioactive water at the Fukushima Daiichi Nuclear PowerStation as the operator continues to inject water into three of its six reactors to keep them cool.The plant suffered meltdowns at the three units after a tsunami sweptthrough the complex in March 2011.