On 16 December 2012, Spain’s oldest nuclear reactor Santa Maria de Garoña was shut down definitively. The operator Nuclenor had calculated that further operation of the 446 MW plant would not be economic. Not only it would have to invest about €120 million to upgrade the 41-year old plant, but it would also have to face a new tax of €153 million in 2013 following an energy tax reform that was overdue in Spain. The plant closure leaves the country with seven operating reactors. Nuclear power generated 20 percent of the electricity in Spain in 2011.