A nuclear power station in southeastern Romania was shut down on Thursday due to a "minor fault" the economic ministry said. He added that the incident did not threaten the plant's safety.
A wrong signal at the plant in Cernavoda "led to an electric generator being disconnected and a drop in pressure", the ministry said in a statement.
"Because of this incident, the Termoelectrica company has put coal-fired power plants in Braila and Borzesti back into service to ensure the country's energy needs are met," the statement said.
Work may begin to get the Cernavoda station up and running again as soon as Friday, the ministry said.
The plant uses the Canadian Candu 6 process, relying on natural uranium and heavy water.
The first and only one of five units originally due to be on-stream by now has a capacity of 705 megawatts and provides around 10 percent of Romania's energy needs.