Spanish nuclear plants undergo preventive maintenance

SPAIN - Maintenance outages have put 5,871 megawatts (MW) of nuclear capacity offline in Spain. The 1,028-MW Asco I, 2,729-MW Almaraz II and 1,087-MW Vandellos II nuclear power plants are offline for refueling and preventive maintenance.

On May 26, the 1,027-MW Asco II plant was forced offline after possible damage was discovered on safety valves. After a 36-hour maintenance outage, the plant was reconnected to the grid.

The valves were reported to be working properly.

In March, the Vandellos II plant was taken offline for its 16th annual outage. In addition to the regular tasks performed during refueling maintenance, a new refrigeration system will be installed and a weld overlay examination will be performed. Once finished, the station will start an 18-month operating cycle. The plant is operated by Asociacion Nuclear Asco-Vandellos and owned by Spanish power companies Endesa (72%) and Iberdrola (28%). The plant was inaugurated in March 1988 and is equipped with a pressurized water reactor supplied by Westinghouse Corporation.

Spain has five other nuclear power stations in operation: the 1,381-MW Santa Maria de Garona, 3,031-MW Trillo, 3,237-MW Confrentes, 1,027-MW Asco II and 2,729-MW Almaraz.

The Asco II plant began operation in March 1986 and is equipped with a pressurized water reactor supplied by Westinghouse and three Siemens AG steam generators. In February 2009, the plant was taken offline for refueling and preventive maintenance. The next scheduled outage is expected to take place in August 2010.