Radioactive water accumulating in Japan’s crippled Fukushima plant may start overflowing from service trenches in five days, potentially increasing the contamination from the worst nuclear crisis since Chernobyl.
Tokyo Electric Power Co. has been manually pumping water into overheating reactors after cooling systems broke down and much of that has overflowed into basements and trenches. The water is rising at a rate that means it will overflow as early as June 6, Bloomberg calculations from the company’s data show.
“There is still a risk of radioactive water leaking into the sea,” Hikaru Kuroda, an official at the utility known as Tepco, said in Tokyo today. “We may have between five and seven days before the water levels reach the top of the trenches.”
Almost 60 percent of Japanese adults worry they’ve been contaminated since Fukushima started emitting radiation almost three months ago, according to a Pew Research Center poll. The poll shows at least 80 percent of the population is dissatisfied with the response either from Tepco or the government of Prime Minister Naoto Kan, who survived a no-confidence vote today.
“Solving the problem of contaminated water is critical,” said Tetsuo Ito, the head of the Atomic Energy Research Institute at Kinki University in western Japan.
Tepco shares rose 2 percent to 305 yen in Tokyo. The stock has fallen 86 percent since March 10, the day before an earthquake and tsunami knocked out power and cooling at the Fukushima Dai-Ichi plant, erasing 3 trillion yen ($37 billion) of the company’s market value.
Tepco has pumped millions of liters of cooling water into the three reactors that melted down. By May 18, almost 100,000 tons of radioactive water had leaked into the basements of reactor and turbine buildings, connecting tunnels and service trenches at the plant, according to Tepco’s estimates.
Water levels are between 27.7 centimeters (11 inches) below the top of a shaft leading to a trench connected to the No. 2 building and 23.9 centimeters below the ground at the No. 3 unit today, Junichi Matsumoto, a general manager at Tepco, said.
The levels were 64.1 centimeters for the No. 2 building and 45.6 for No. 3 on May 27, showing a rate of increase that will reach the lip of the trenches as early as June 6.
To prevent leakage into the ocean, Tepco poured concrete and gravel to seal trenches closest to the sea near the No. 2, 3 and 4 reactors, Tepco spokesman Takeo Iwamoto said by phone.
“We are still considering the measures to be taken if contaminated water leaks,” Iwamoto said today.
The company may transfer more water than planned to a waste story facility to avoid overflows, Matsumoto said.
“There are likely to be underground leakage pathways that will be very hard to plug, and therefore the only way to stop the ongoing marine contamination is to remove the water from basements and other structures as quickly as possible,” environmental group Greenpeace International said in a statement.
The rate of increase in water level quickened because of three days of rain from typhoon Songda that weakened as it swept past Japan earlier this week. Namie, a town near the Fukushima Dai-Ichi station, had 112 millimeters of rain on May 30, according to the Japan Meteorological Agency.
Japan is regularly buffeted by typhoons and tropical storms between May and October, adding another risk to containing the radiated water at the Fukushima station. Hydrogen explosions at the plant blew the roofs off three reactor buildings, exposing pools containing spent fuel rods.
Takeo Iwamoto, a spokesman for the utility, said the company plans to complete installing covers for the buildings by October.
In early April, Tepco spent days trying to stop a leak of highly radioactive water into the sea from a pit near the No. 2 reactor. It turned to using concrete, sawdust, newsprint and absorbent polymer used in diapers to block the leak.
The efforts failed and drew comparisons with BP Plc’s attempts to plug an oil leak in the Gulf of Mexico last year with golf balls and strips of rubber tires. The Tepco leak was eventually sealed with sodium-silicate, known as liquid glass.
Tepco on April 5 said it had dumped almost 10 million liters (2.6 million gallons) of radioactive water into the sea from the Fukushima plant, which led to radioactive cesium being found in fish at levels exceeding health guidelines.
The company said at the time the decision was the lesser of two evils as it needed to find space for storing water that was highly radioactive and more toxic that what was released into the sea.