Utility Starts Filtering Water at Stricken Japanese Nuclear Plant

The filtering equipment, hastily cobbled together by several foreign and Japanese companies, is urgently needed because the storage facilities at the power plant are glutted with tens of thousands of tons of radioactive water, and are expected to overflow as soon as next week if nothing is done.

If that occurs, Tokyo Electric, known as Tepco, will be forced to dump thousands of tons of even more tainted water into the ocean, and would probably bring down even more criticism on the embattled company and the government, which has been attacked for its handling of the crisis.

Hoping to avoid releasing any more contaminated water, Tepco in late April set out an ambitious nine-month road map for stabilizing conditions at its nuclear reactors. The plan includes setting up a sprawling water treatment facility that is expected to cost about $663 million. Built under the supervision of Toshiba and Hitachi, the filtration system is meant to sift out oil, and then cesium and other radioactive elements, before desalinating the remaining water.

The system is expected to process about 1,200 tons of water a day, which will be stored in tanks, some of which are being brought to the compound. Some of the filtered water will be reused to cool the reactors, reducing the need for fresh supplies. Tepco plans to filter water for about a year, according to Junichi Matsumoto, a spokesman.

Tepco originally planned to begin operating the facility in July, but it sped up construction because contaminated water had been produced faster than expected at the nuclear plant. A leaky valve halted testing of the system on Thursday, and there were several more delays on Friday, before it finally got running. Tepco acknowledged that the system could falter again and have to be shut down for repairs.

While the filtration system was being built, Tepco reduced the amount of water it was pouring into the plant’s stricken reactors to avoid filling up its storage facilities.

The beginning of the rainy season this month has complicated efforts to slow the creation of toxic water.

“It is something like a chemical plant constructed in a rush, so we have to go by trial and error,” said Hidehiko Nishiyama, deputy director general of the Nuclear and Industrial Safety Agency, referring to the repeated problems that have plagued the project. “We have had to do this in a hurry, so conditions have been very severe.”

In all, about 500 tons of water is newly contaminated at the plant each day, adding to the 105,000 tons of highly radioactive water that is already stored on the site, mostly in the trenches and basements of the turbine and reactor buildings. Many of these areas are perilously near full to the brim. In the trenches at the No. 3 reactor, for example, there was just seven inches to spare on Friday.

Critics contend that while the filtration system will delay the runoff of radioactive water for a while, Tepco will continue to face water disposal problems because it may take years to fully cool the reactors at the plant.

“It’s just a matter of time before it overflows,” said Satoshi Sato, a nuclear engineer who formerly worked for General Electric at the reactors in Fukushima. “It’s an endless game.”

The water stored at the plant is contaminated with cesium 134, cesium 137 and iodine 131 with a total radioactivity estimated at 720,000 terabecquerels, more than the amount of radioactive material that has been spewed into the air at the plant so far.

The new filtration system still faces many hurdles. The companies operating it, including Areva from France and Kurion from the United States, have little experience working with seawater. And Tepco must still dispose of the radioactive material that is being sifted out of the waste water; it is mixed with a chemical agent to create a toxic sludge.

During the summer, Tepco will bring 370 tanks to the Daiichi plant to store an extra 40,400 tons of radioactive water. A mega-float that can store yet more water is moored near the plant.

The contaminated water has been an unavoidable side effect of Tepco’s “feed and bleed” strategy for dealing with the four destroyed reactors at Fukushima Daiichi. To cool them for eventual dismantling, the company is pouring huge volumes of fresh water and sea water directly onto the highly radioactive reactors, which contaminates the water, creating an environmental headache.

The devilish consequences of the company’s efforts became clear in April, when rivers of contaminated water seeped through cracks in drainage pits and flowed directly into the Pacific Ocean. While that leak was plugged, a lack of storage for contaminated water soon forced Tepco to deliberately release an additional 11,500 tons into the sea.

The dumping led to an international outcry. In waters near the plant, a variety of fish and seaweed were found with higher than normal levels of radioactivity, prompting a ban on the sale of marine products harvested from parts of Japan’s Pacific coast.

Several workers at the plant have been burned around their feet and ankles after they stepped in highly radioactive water. Reducing the amount of water in and around the power plant will make it easier for workers to undertake other repairs.

Yasuko Kamiizumi and Kantaro Suzuki contributed reporting.

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