Radiated Water at Fukushima Plant May Breach Storage Trenches in Five Days

Radioactive water accumulating in Tokyo Electric Power Co.’s crippled Fukushima Dai-Ichi nuclear plant is set to start overflowing from storage trenches in five days, data provided by the company show.

To prevent leakage into the ocean, the utility has poured concrete and gravel to seal off storage trenches closest to the sea containing water from the No. 3 and No. 4 reactors, according to Hikaru Kuroda, a nuclear facility maintenance official at the company.

“Even as we have sealed these trenches, there is still the risk of radioactive water leaking into the sea,” he said to reporters after a media conference yesterday. The company is seeking additional storage space to move the water from trenches to reduce such risk, he said.

The utility known as Tepco has pumped millions of liters of cooling water into the three reactors that melted down after the March 11 earthquake and tsunami. By May 18, almost 100,000 tons of radioactive water had leaked into basements of reactor and turbine buildings and connected tunnels and storage trenches at the plant, according to Tepco’s estimates.

Water levels are between 26.5 and 33.2 centimeters (10 and 13 inches) below the top of storage trenches for the No. 2 and No. 3 reactors, according to Tepco figures dated June 1. The water levels were 45.6 and 64.1 centimeters on May 27, showing a rate of increase that will reach the lip of the trenches as early as June 6.

Workers will seal off trenches for the No. 2 reactor today in a process that will funnel radiated water to other trenches, Tepco spokeswoman Ryoko Sakai said by telephone yesterday.

Typhoon Season

The contaminated water is a “massive problem,” Tetsuo Iguchi, a specialist in isotope analysis and radiation detection at Nagoya University, said in a phone interview on May 27. Tepco has to ensure the contaminated water doesn’t get into the soil, Iguchi said.

The rate of increase in water level quickened because of three days of rain from typhoon Songda that weakened as it swept pass 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 during the northwestern Pacific cyclone season, 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.

Tepco said last week it was still considering typhoon measures and that it couldn’t announce detailed plans. Takeo Iwamoto, a spokesman for the utility, said it plans to complete installing covers for the buildings by October.

Plugging Leaks

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.

– Bloomberg