Possible leak at damaged Japanese nuclear plant

Apr 26, 2011, 10:21 GMT

Tokyo - Japan's nuclear safety agency said Tuesday that water may be leaking from a reactor containment at the quake-damaged Fukushima nuclear plant, likely hampering efforts to cool down its fuel.

'We are currently examining data, but we think that there is water leakage to some extent,' Hidehiko Nishiyama, the agency's spokesman, told a news conference.

Data suggested the leak at reactor 1 was caused by nitrogen being injected into the container to reduce the risks of hydrogen explosions, Kyodo News reported citing the agency.

Remote-controlled robots were to enter the building later Tuesday to observe the primary reactor container, Nishiyama said.

Officials from plant operator Tokyo Electric Power Co (TEPCO) did not notice signs of any leakage in earlier data collected by the robots, Kyodo said.

Meanwhile, Industry Minister Banri Kaieda ordered TEPCO to report data on the plant's reactors, such as pressure and temperature, taken during the immediate aftermath of the March 11 earthquake.

'There was about an hour until a tsunami hit the plant after the quake. So we believe that some of the data remain at the site,' Nishiyama said.

TEPCO has so far released post-quake data starting about five hours after the 2:46 pm (0546 GMT) quake. The data is believed to be inside the plant's central control rooms where radiation levels are still high, Kyodo said.

The levels of radioactive water in reactors have risen over the past month, public broadcaster NHK reported, citing TEPCO.

The levels of caesium-134 and -137 increased about 250-fold and iodine-131 increased about 12 times in the basement of the turbine building of reactor number 4. That level of contamination requires TEPCO to prioritize the transfer or disposal of the rapidly rising water.

Highly contaminated water in some of the plant's six reactors has prevented workers from restoring key cooling functions at the plant.

TEPCO is currently transferring highly radioactive water from the trench of reactor number 2 to a temporary storage facility.

In Tokyo, farmers affected by the nuclear fallout staged a protest in front of the TEPCO headquarters, demanding the company put the plant under control and compensate them as soon as possible.

Some 200 farmers from Fukushima, Chiba, Ibaraki and other prefectures joined in the protest, displaying vegetables and milk cows, shipments of which have been banned due to radiation concerns, NHK reported.

With Tuesday marking the 25th anniversary of the 1986 Chernobyl disaster in Ukraine, the Japanese government said the nation had taken advantage of lessons learned in the aftermath of the accident to cope with its own ongoing nuclear crisis.

'The studies and research on what kind of health problems could emerge based on Chernobyl have become an asset and knowledge shared by all humanity,' Chief Cabinet Secretary Yukio Edano said.

The Ukrainian ambassador to Japan urged Tokyo on Tuesday to disclose all data and seek further international cooperation to deal with the ongoing nuclear crisis.

Mykola Kulinich said those were the crucial lessons of the Chernobyl disaster, the world's worst nuclear accident, when it was part of the Soviet Union.

'In our case, we lost the chance of international cooperation to handle this accident at the very beginning. We tried to manage everything by our own. Any advice (from) outside was ignored,' Kulinich said.

Two weeks ago, the Japanese government raised the accident level at the plant to 7, the highest on an international scale, putting it on a par with the 1986 Chernobyl disaster.

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