Officials at Japan's troubled Fukushima nuclear power plant said Thursday they are considering releasing more low-level radioactive water into the ocean.

Tokyo Electric Power Company warned that by March it may no longer have space to store the massive amount of water used to cool the damaged reactors at the plant.

TEPCO says it would only release the water after it is filtered to reduce levels of radioactive substances. The utility is also considering building more storage tanks to hold the radioactive water, but says it cannot do so indefinitely.

The plant operator already released tens of thousands of tons of contaminated water into the Pacific Ocean following the March disaster at the facility, which was crippled by a massive quake and ensuing tsunami.

The company says it is working to determine the environmental impact of releasing more waste water into the sea. A group representing Japanese fishermen is demanding that TEPCO scrap the idea.

Separately, TEPCO said on Monday that 45 tons of radioactive water has recently leaked from a purification device at the plant. Some of the water included the highly dangerous substance known as strontium, which is linked to bone cancer.