GO
Loading...

Japan nuclear plant leaks 300 tons of radioactive water

A satellite image of the Fukushima Nuclear Reactor following concerns over a build-up of radioactive ground water.
DigitalGlobe | ScapeWare3d | Getty Images
A satellite image of the Fukushima Nuclear Reactor following concerns over a build-up of radioactive ground water.

The operator of Japan's crippled Fukushima nuclear plant said on Tuesday it believes about 300 tons of highly contaminated water has leaked from a storage tank designed to hold overflows from the site.

Japan's Nuclear Regulation Authority has classified the leak as a level 1 incident, the second lowest, on an international scale for radiological releases, a spokesman told Reuters on Wednesday.

(Read more: Nuclear body declares 'emergency' at Fukushima)

It is the first time Japan has issued a so-called INES rating since three reactors melted down at Fukushima in March 2011, shortly after the plant was wrecked by a an earthquake and tsunami, and the disaster was assigned the highest rating of 7.

Since then, the operator, Tokyo Electric Power, has been struggling to contain radioactive leaks to the growing alarm of neighboring countries. It has been criticized for its failure to prepare for the disaster and it has also been accused of covering up the extent of the problems at the plant.

A puddle that formed near the tank that leaked is emitting a radiation dose of 100 millisieverts an hour measured about 50 centimeters (1.6 feet) above the surface, Kyodo News reported, citing Tokyo Electric.

(Read more: Japan nuclear body says radioactive water at Fukushima an 'emergency')

That is equivalent to the limit for accumulated exposure over five years for Japanese nuclear workers.

A spokesman for the operator, known as Tepco, said the information on the dose rate did not come from the company, saying only the leaked water contains 80 million becquerels of radiation per liter, without putting it into perspective.

A becquerel is a measure of the release of radioactive energy, while dose rate indicates how much radiation a person would receive standing near the source of radiation.

Tokyo Electric uses a jerry-rigged system to wash water over the melted uranium fuel rods to keep them cool and stable. The water flows into basements that have been leaking since the disaster.

Highly contaminated excess water is pumped out and stored in steel tanks on elevated ground away from the reactors, which lie adjacent to the coast. Tepco said it does not believe the water that leaked from the storage tank, which is about 500 meters (550 yards) from the shore, has escaped into the ocean.

(Read more: Tepco: Fukushima likely leaking radioactive water into sea)

But only this month the company, after months of denial, admitted contaminated water escaping from basements and trenches closer to the coast is reaching the ocean, prompting the government to step up its involvement in the plant's cleanup.

A South Korean Foreign Ministry spokesman confirmed on Tuesday media reports that the country's government has asked Japanese officials to explain the leakage of contaminated water into the Pacific Ocean.

Contact Asia News

  • CNBC NEWSLETTERS

    Get the best of CNBC in your inbox

    To learn more about how we use your information,
    please read our Privacy Policy.
    › Learn More

Asia Video

  • Hartmut Issel, Head of Wealth Management Research, Singapore at UBS, outlines his expectations for various asset classes in 2015 as global central banks pursue differing policies.

  • Peter Churchouse, Author of The Churchouse Letter, says the verdict on property tycoon Thomas Kwok and the government's former deputy leader Rafael Hui sent a clear message on HK's rule of law.

  • Adrian Mowat, MD, Chief Asian & Emerging Market Equity Strategist at J.P. Morgan, attributes the upgrade to possible stability in the ruble and oil prices. He also explains why he likes other EMs, such as Turkey and China.