Hokuriku Electric Power Co and Chubu Electric Power Co said that Hitachi has agreed to pay the entire costs of repairing the faulty turbines that caused unplanned stoppages at two of their nuclear power reactors in 2006.
In June 2006, a malfunction occurred in the low-pressure steam turbine of Chubu's Hamaoka 5 nuclear power reactor. The unit automatically shut down due to abnormal vibrations being detected. An inspection revealed that the turbine's blades had broken. The turbine had been designed and manufactured by Hitachi.
A safety inspection in July 2006 at Hokuriku's Shika 2 reactor - which is of identical design to Hamaoka 5 - also found that blades had broken in a turbine, also supplied by Hitachi.
In Hamaoka 5, damage was found in 663 out of 840 of the moving blades on the twelfth stage of the low-pressure turbine. One of the blades was found to be fractured. In Shika 2, damage was found in 258 out of 840 of the moving blades on the twelfth stage of the low-pressure turbine. Investigations suggested that unanticipated vibration during test operations had caused metal fatigue that led to cracks at the base of the blades, which progressively worsened.
Hitachi conducted inspections and initial repairs at the two reactors. Chubu restarted Hamaoka 5 in March 2007. Hokuriku planned to restart Shika 2 in May 2007 but was forced to keep the entire plant offline after it was discovered that the utility had covered up a previous accident at Shika 1 in March. Hitachi has since redesigned and manufactured the turbine blades so that they can withstand high vibration levels.
Hitachi has now reportedly agreed to pay all the costs associated with repairing the turbines at the two reactor units. The company said that it did not expect the costs to affect its financial results in the current financial year, ending in March 2008, as it factored in an expected cost Y38 billion ($330 million) in last year's earnings to repair the turbines. Hitachi said in late 2006 that it did not expect to pay any additional costs regarding the turbines.
However, Chubu and Hokuriku said they are still in talks with Hitachi regarding compensation for the cost of purchasing additional fuel for their thermal power plants which were used to meet power demand while the reactors were out of operation.
Chubu Electric Power Co
Hokuriku Electric Power Co
WNA's Nuclear Power in Japan information paper
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