Spain's Asco 1 nuclear plant taken offline for three-day halt

Barcelona — Spain's 1.03 GW Asco 1 nuclear plant was taken offline for an unplanned halt, operator Centrales Nucleares Asco Vandellos 2, or ANAV, said Sept. 5, leaving Spanish nuclear output at around 6 GW on Sept. 7.

The plant, 100% owned by Endesa, was disconnected at 4:45 am CET (2:45 am GMT) to replace a valve in a heat extraction unit.

The plant has been left on warm standby mode, meaning it will be quicker to reconnect to the grid once the work is finished.

The plant is due to come back online Sept. 8, according to data from European transparency platform Entso-e.

Spanish nuclear output on Sept. 7 was around 6 GW, with the country's other six nuclear units all in operation.

Another one of ANAV's plants -- the 1.09 GW Vandellos 2 -- was halted on Sept. 1 for a brief maintenance in the cooling system, coming back online Sept. 3.

The group's third plant, Asco 2, is due offline on Oct. 3 for a scheduled refueling halt through to Nov. 5.