Tokyo Electric Power Co. played down concern that a solution to the crisis at its Fukushima nuclear plant may be delayed, saying it plans to resume clearing radioactive water that’s hindering recovery work.
Decontamination of the water was halted on June 18 after radiation levels in a treatment unit exceeded the limit set by the utility in five hours, instead of one month as expected. The company plans to resume full operation of the system after assessing the cause of the readings, Junichi Matsumoto, a general manager, said today in Tokyo.
“Decontamination is the key to solving the problems at the plant,” Tadashi Narabayashi, a nuclear engineering professor at Hokkaido University, said yesterday. “They put together equipment from different manufacturers, which may have made the system as a whole vulnerable.”
Filtering of about 105 million liters (28 million gallons) of water in basements and trenches at the Fukushima Dai-Ichi plant was halted after the level of cesium in a unit reached 4.7 millisieverts of radiation. Filters generally need replacement at a level of 4 millisieverts, and the company had expected the unit to last about a month, Matsumoto said.
Tokyo Electric hasn’t determined when it will restart decontamination, Matsumoto said.
The company known as Tepco is using a cesium absorption unit from Kurion Inc. of the U.S. After the water passes through that unit it goes to a decontamination facility supplied by Areva SA of France.
“Tepco should have had a very simple water decontamination system of its own,” Narabayashi said. “Then, it’s easy to fix or replace a troubled part by themselves.”
Tepco on April 17 outlined plans to end within six to nine months the world’s worst nuclear crisis since Chernobyl in 1986. The first stage is to reduce radiation levels at the plant within three months and then achieve a so-called cold shutdown where reactor temperatures fall below 100 degrees Celsius (212 degrees Fahrenheit).
The Fukushima plant had three reactor meltdowns after the March 11 earthquake and tsunami knocked out power and backup generators, crippling its cooling systems. Japan in April raised the severity rating of the crisis to 7, the highest on an international scale and the same as the Chernobyl disaster.
Tepco has been criticized for its slow response to the accident and for publishing erroneous radiation data, while the government-run Nuclear and Industrial Safety Agency has been blamed for not ensuring the utility heeded warnings that a tsunami could overwhelm the plant’s defenses.
The utility is now the subject of study by Yotaro Hatamura, who was appointed by Prime Minister Naoto Kan last month to head a 10-member team conducting an “impartial and multifaceted” investigation into what went wrong and how to prevent a repeat.
The nation’s largest banks and insurers, including Sumitomo Mitsui Financial Group Inc. and Dai-ichi Life Insurance Co., will provide short-term operating funds to Tokyo Electric, according to local media reports.
Japan’s government is discussing plans for a fund of several hundred billion yen to finance reconstruction and support families and companies in the disaster-hit prefectures of Fukushima, Miyagi and Iwate, the Nikkei newspaper reported yesterday.
Fukushima Governor Yuhei Sato reiterated his opposition to restarting Tepco’s nuclear reactors in the prefecture, the Asahi newspaper reported yesterday. Sato said he will respect and adhere to the denuclearization outline of a prefectural committee on reconstruction, the newspaper reported.
Trade Minister Banri Kaieda said on June 18 that he may let utilities restart nuclear generators that had been shut for routine maintenance. There are negatives to suspending all nuclear power, Kaieda said, citing an expected “gap” in power supply and demand in Japan’s coming summer months.
Hatamura indicated his team will probe whether an earthquake-prone country such as Japan should build its energy policy around nuclear plants. Because of the inherent dangers, it’s a mistake to treat the industry as safe, he said.
Tepco shares rose 4 percent to close at 314 yen on the Tokyo Stock Exchange today. The stock has fallen 85 percent since the day before the quake.
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