The operator of the troubled Fukushima Daiichi nuclear power plant has shown the media a system it plans to use to release treated and diluted water from the facility into the ocean.

Tokyo Electric Power Company, or TEPCO, completed the construction of the system on Monday. It has been building it since last August.

A gigantic pipe for diluting treated water with a massive amount of seawater has been installed in front of the No.5 and the No.6 reactors.

It is about 2 meters in diameter and around 7 meters long.

TEPCO says an emergency shut-off valve on the system automatically stops the flow of the treated water and seawater if the flow-rate does not match prescribed rates or concentrations of radioactive materials are above permitted levels.

The utility is now conducting simulator training for workers to help ensure the system's safe operation.

Water used to cool molten nuclear fuel has been collecting in storage tanks at Fukushima Daiichi. It has been filtered to remove most radioactive materials, but it still contains tritium.

The government plans to dilute it to reduce the tritium levels to about one-seventh of the World Health Organization's safety standards for drinking water before starting to discharge it sometime around this summer.