Tokyo Electric Power Co. said Monday it has resumed test operations of the new high-tech water treatment system at the Fukushima No. 1 nuclear plant, following its suspension late last week.

The advanced liquid processing system, known as ALPS, was suspended Friday after the utility detected a problem in one of the machines. The system has three lines, A, B and C. The C line is the one that developed the latest glitch.

Tepco determined Sunday that a rubber sheet left in a water tank near the system was obstructing the drain outlet.

ALPS is intended to remove most radioactive materials from contaminated water and is expected to play a crucial role in the utility's fight against the toxic water continuing to accumulate at the crippled nuclear plant.

ALPS was restarted on a trial basis after midnight Thursday and had processed around 100 tons of toxic water before the suspension.

The current water treatment facility at Fukushima No. 1 can only remove cesium, while ALPS can extract 62 different types of radioactive materials, with the exception of tritium.

Initially, Tepco started a trial run of lines A and B in March, but halted all operations in June after the tank for line A was found leaking because of internal corrosion. While Tepco commenced repairs and investigated the problem, it sped up efforts on line C, which at the time was still waiting to be tried out.