Tepco Reports More Radioactive Water Leaks

By Tsuyoshi Inajima - Dec 5, 2011 11:00 AM GMT+0700

As much as 45,000 liters (11,870 gallons) of highly radioactive water leaked from Japan’s crippled Fukushima nuclear station at the weekend and some may have reached the sea, Tokyo Electric Power Co. (9501) said.

The leakage shows the company known as Tepco is still struggling to control the disaster nine months after an earthquake and tsunami wrecked the plant. The water contained 1.8 millisieverts per hour of gamma radiation and 110 millisieverts of beta radiation, Tepco said in an e-mailed statement yesterday.

“The source of the beta radiation in the water is likely to include strontium 90, which if absorbed in the body through eating tainted seaweed or fish, accumulates in bone and can cause cancer,” said Tetsuo Ito, the head of Kinki University’s Atomic Energy Research Institute.

Since the March 11 disaster, the utility has reported several leaks of radiated water into the sea, though its estimates of their size have been disputed. In October, a French nuclear research institute said the Fukushima plant was responsible for the biggest discharge of radioactive material into the ocean in history.

The water leaked from a desalination unit and through a cracked concrete wall into a gutter that drains into the Pacific Ocean, spokeswoman Chie Hosoda said by phone. Radiated water has now been pumped out of the building where it was leaking from.

Environmental Checks

As much as 300 liters leaked through the crack, Junichi Matsumoto, a general manager at the utility, told reporters in Tokyo today. The utility is still checking how much contaminated water has reached the sea and the effects on the environment, Matsumoto said.

Tepco said the leaked water contained 16,000 becquerels and 29,000 becquerels per liter of radioactive cesium 134 and 137 respectively. Those levels exceed government safety limits by 267 and 322 times, according to Bloomberg calculations.

The water may have contained one million times as much radioactive strontium as the government limit, the Asahi newspaper reported today. Matsumoto said Tepco may take three weeks to analyze the strontium level in the water.

The study by the French government-funded Institute for Radiological Protection and Nuclear Safety said radioactive cesium that flowed into the sea from the Fukushima Dai-Ichi nuclear plant was 20 times the amount estimated by Tepco.

Prolonged exposure to high levels of radiation can cause leukemia and other forms of cancer, according to the World Nuclear Association.

To contact the reporter on this story: Tsuyoshi Inajima in Tokyo at tinajima@bloomberg.net

To contact the editor responsible for this story: Peter Langan at plangan@bloomberg.net