None of the incidents was serious and there was no danger to workers or the environment at any time.
Four Spanish nuclear plants have suffered some form of breakdown over the past 72 hours.
The Vandelòs II plant saw its fire-detection systems activated.
Asco II had a problem in the refrigeration system.
Asco I had a problem in valve in a heat extractor.
The Confrentes plant in Valencia saw an unplanned power surge.
All the incidents have been confirmed by the Nuclear Safety Council CSN, which has said that none of the incidents resulted in any risk to workers, the local populations or the environment.