The water level in basements and trenches at Tokyo Electric Power Co.’s Fukushima plant rose and may contain more radiation than is known to have been released into the atmosphere in the worst nuclear crisis since Chernobyl.
The amount of contaminated water rose to about 105 million liters (28 million gallons) from 100 million liters on May 18, and may start overflowing after June 20, the company known as Tepco said in a statement today. Radiation in the water is estimated at 720,000 terabecquerels, general manager Junichi Matsumoto said at a media briefing in Tokyo.
Tepco has pumped millions of liters of water to cool three reactors that melted down at the Fukushima Dai-Ichi station after the March 11 earthquake and tsunami knocked out power and backup generators, crippling its cooling systems. With Japan’s rainy season in full swing, heavy downpours threaten to flood the plant and leak more radiation into the sea, soil and air.
“The risk of overflow is as serious as the meltdown of reactor fuel rods that’s already happened,” Tetsuo Ito, the head of the Atomic Energy Research Institute at Kinki University in western Japan, said in a phone interview. “Tepco should’ve acknowledged this risk weeks ago and could’ve taken any urgent measures.”
A water de-contamination unit being built at the plant will start operating after June 15 and an underground tank capable of holding 10 million liters will be ready by the middle of August, Tepco said in today’s statement.
Radiation in Atmosphere
Tepco shares fell 6.2 percent today to 286 yen, the lowest level since at least September 1974. The stock has fallen 87 percent since the day before the quake, erasing 3 trillion yen ($37 billion) of the company’s market value.
Much of the water poured into reactors and spent-fuel pools has overflowed or leaked into basements, connecting tunnels and services trenches at the plant, which has six reactors housed in separate building.
Japan’s Nuclear Safety Commission said on April 12 an estimated 630,000 terabecquerels of radiation had been released into the atmosphere. The country’s government the same day raised the severity rating of the nuclear crisis to the highest level on an international scale.
The government aims to release the latest radiation data early next week, Goshi Hosono, a special adviser to Japanese Prime Minister Naoto Kan, said on June 1.
Failure of cooling systems for reactors and water pools storing spent fuel rods led to explosions and fires at the Fukushima plant, causing radiation leaks that forced the evacuation of more than 50,000 households and contaminated drinking water and food.
Japan’s government halted shipments of tea from four prefectures near Tokyo after detecting radioactive cesium that exceeded regulatory limits, the Yomiuri newspaper reported today.