Areva to Deliver Water-Treatment Unit to Tepco's Crippled Fukushima Plant
Areva SA (CEI) will deliver a decontamination unit to Japan’s crippled nuclear power plant, where Tokyo Electric Power Co. is removing radioactive water so it can start repairing cooling pumps and power systems.
Areva will set up the water treatment plant, which separates and recovers radioactive particles, at the Fukushima site, the French nuclear operator said today in a statement. Tepco, as the Japanese company is called, wants to start using the unit by June, Junichi Matsumoto, a general manager, said at a press briefing in Tokyo.
The Fukushima plant was damaged by explosions in the days after a magnitude-9 quake and tsunami on March 11 knocked out cooling equipment, sparking the worst nuclear disaster since Chernobyl in 1986. Tepco today started pumping contaminated water out of trenches near one of the reactor buildings that were damaged by the blasts.
“The contaminated water must be treated rapidly as it is preventing Tepco from repairing the power plant’s power supply and cooling systems,” Areva said in the statement. The unit “will sharply reduce the radioactivity levels of the treated water, which could be reused in the power plant’s cooling systems.”
The treatment unit, which will be provided by Veolia Water, can process 50,000 liters (13,200 gallons) of water per hour, Areva Chief Executive Officer Anne Lauvergeon said today at a briefing in Tokyo.
She said Areva hasn’t proposed a plan for decommissioning the reactors, which have been spewing radiation into the air and sea for more than five weeks
Pouring Water
The Fukushima plant, 220 kilometers (137 miles) north of Tokyo, has six reactors, three of which were shut for maintenance when the earthquake and tsunami struck, leaving almost 28,000 people dead or missing.
Tepco has been pouring millions of liters of water to cool the reactors and spent fuel after the accident, which has flooded basements and trenches near the reactors. Some highly contaminated water leaked into the sea and the utility has dumped less toxic fluids into the ocean.
Tepco started draining highly radioactive water from trenches around the No. 2 reactor at about 10 a.m. today, spokesman Osamu Yokokura said.
The power utility aims to move 10 million liters (2.6 million gallons) of the contaminated water to a waste treatment unit and expects to complete the transfer in 26 days, Matsumoto told reporters at an earlier briefing today.
Filling Vessels
In the next three months, Tepco plans to fill the reactor containment vessels at the No. 1 and No. 3 units with water, the company said in its statement on April 17 outlining its plan for bringing the situation under control. The utility will seal the vessel of the No. 2 reactor, which is likely damaged, before flooding it.
“If we flood the damaged vessel, the leak of contaminated water will increase,” Tepco Vice President Sakae Muto told reporters. “We will continue injecting water with care and monitor the volume of water leaked.”
Two iRobot Corp. (IRBT) robots sent into reactor buildings on April 17 to check whether humans can reenter them found radiation levels as high as 49 millisieverts per hour inside the No. 1 unit, and up to 57 millisieverts in the No. 3 unit, the Nuclear and Industrial Safety Agency said.
The cumulative maximum level for nuclear workers was raised to 250 millisieverts from 100 millisieverts by Japan’s health ministry on March 15. Exposure totaling 100 millisieverts over a year is the lowest level at which any increase in cancer is evident, according to the World Nuclear Association in London.
Judging Limits
Another robot was sent into the reactor No. 2 building yesterday and recorded levels of 4.1 millisieverts per hour, spokesman Tetsuya Terasawa told reporters today. That level wouldn’t prevent workers going into the building, another spokesman said.
“We judge the radiation limit by the amount, importance and hours of the work, as well as accumulated exposure of each worker,” spokesman Shogo Fukuda said. “We wouldn’t hesitate to send workers in at a level of 4.1 millisieverts per hour.”
Fuel pellets in the No. 1, 2 and 3 reactors may have melted at the plant, the nuclear safety agency said today, in the first official confirmation of damage to the cores.
“It is believed that the fuel pellets in the reactors have melted,” the agency said in a report. “The extent of the melting cannot be confirmed until the fuel rods have been removed.”
A sustained drop in radiation at the Fukushima Dai-Ichi station may be achieved within three months, Tokyo Electric Power Co. said in the statement laying out its plans.
Cold Shutdown
Following that, a cold shutdown, where core reactor temperatures fall below 100 degrees Celsius (212 degrees Fahrenheit), may be achieved within six months, it said.
“Tepco needs to be faster than it has outlined on two particular areas: circulating the radioactive water back into the pressure vessels and covering the reactor buildings to prevent radiation releases,” Tadashi Narabayashi, a professor of nuclear engineering at Hokkaido University, said today.
Shares of Tepco fell 4.3 percent to 447 yen today in Tokyo. The stock is down about 80 percent since the quake and tsunami.
Three to six months after the initial phase of its plan, Tepco will attempt a cold shutdown of reactors No. 1, 2 and 3, the company said. Reactors 4, 5 and 6 were shut at the time of the disaster.
The utility will also cover the No. 1, 3 and 4 reactor buildings as a temporary measure to reduce radiation emissions after the structures were damaged by hydrogen blasts last month, according to the statement.
To contact the reporters on this story: Yuji Okada in Tokyo at yokada6@bloomberg.net; Michio Nakayama in Tokyo at mnakayama4@bloomberg.net; Tsuyoshi Inajima in Tokyo at tinajima@bloomberg.net
To contact the editor responsible for this story: Amit Prakash at aprakash1@bloomberg.net
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