Tepco reports another contaminated water leak at Fukushima

Tokyo Electric Power Co (Tepco), the operator of Japan's crippled Fukushima nuclear plant said on Tuesday that four tonnes of rainwater contaminated with low levels of radiation leaked during an operation to transfer the water between tank holding areas.

The company has been trying to contain contaminated water at the Fukushima site after the leak of 300 tonnes of radioactive water from a tank at the plant.

A March 2011 earthquake and tsunami led to triple nuclear meltdowns and hydrogen explosions that crippled the reactor, where operations to control the radiation are ongoing.

A recent typhoon flooded one of the tank holding areas where Tepco stored excess water it flushed over damaged reactors in efforts to keep them cool, according to a spokesman.

Tests conducted last month showed the radiation level of rainwater as 160 becquerels per litre, a relatively low level, following which they decided to transfer the water to another holding area for tanks, he said.

The spokesman added that during the transfer a worker found the leak, which according to the company's estimate was 4 tonnes and was absorbed in the ground.

During the transfer a worker found the leak, which the company estimated to be 4 tonnes and was absorbed into the ground, the spokesman said.

The leak happened after workers overfilled a storage tank according to Tepco.

Tepco added, the workers miscalculated the capacity of the tank as it was tilted on unlevel ground.

BBC quoted Tepco official Masayuki Ono as saying, the company would like to apologise to announce that there had been another leak in its tanks.

He added, this was partly due to the fact that the company had had to fill its tanks to the brim in order to deal with the difficult management of rain water overflow following a typhoon.

According to chief cabinet secretary Yoshihide Suga Tepco had failed to deal with the leaks successfully, the BBC reported.