A power-generating turbine at the first reactor of the Temelin nuclear plant was shut down again on Thursday morning only hours after the power station was reconnected to the national grid on Wednesday evening. The plant had been shut down on Monday because of the same problem. A spokesman has said technicians will replace insulation in the electric part of the turbine, adding that the latest stoppage did not affect the nuclear reactors. Since the controversial plant was launched in October 2000, it has been plagued with technical faults and has been shut down dozens of times. The shutdown comes just days after government regulators approved a request to graduate the first unit from the "testing" stage of operation to the "trial" stage. Last month, regulators approved the test start-up of Unit 2.