Fukushima steps up efforts to freeze radioactive water

Tokyo, July 24: The operator of the tsunami-crippled Fukushima nuclear power plant has said it will accelerate the process of freezing irradiated water in underground tunnels.

Tokyo Electric Power Company (TEPCO) would thus comply with the requirements of Japan's Nuclear Regulation Authority (NRA), which has expressed concern over the delays in carrying out the work, Japanese state broadcaster NHK reported Wednesday.

The objective is to contain flow of radioactive water into the ocean.

At present, the water used to cool "melted-down fuel in damaged reactors has leaked out of reactor buildings into underground utility tunnels" and "tainted runoff, mixed with groundwater, is believed to be seeping into the ground and ending up in the sea", the NHK said.

The method planned by TEPCO involves freezing the underground tunnels by surrounding them with other pipes that will inject coolant at very low temperatures.

The tunnels have not yet been frozen due to technical difficulties, meaning TEPCO has fallen short of the regulator's deadline.

To resolve the issue, TEPCO will install additional pipes with coolant, introduce blocks of ice in the tunnels, and use sandbags to seal off other areas that cannot be frozen.

This project is separate from a larger one that TEPCO is carrying out to build an underground "wall of ice" around the four damaged reactors.

The work, which is scheduled to be completed in 2020, will prevent highly radioactive water that has accumulated in the reactors' basements from mixing with groundwater and seeping into the sea.

The delay in completing the first project could also affect the "wall of ice", the NRA warned.

It is believed that everyday 300 tonnes of contaminated water are seeping into the sea from the plant.

The Fukushima facility was battered by a powerful March 2011 earthquake and a subsequent tsunami, resulting in the worst nuclear disaster since the 1986 meltdown of the Chernobyl plant in Ukraine.

Because of the emissions and resulting radioactive waste, 50,000 people who lived near the plant were forced to evacuate and have not been able to return home.

The disaster also severely affected the local agriculture, livestock and fishing industries.

IANS