Spanish nuclear output was lower than expected at 5.1 GW Monday after an outage at the 1 GW Vandellos 2 nuclear plant was extended for a further week.
The plant was due back online at the weekend, on April 6, but its operator Centrales Nucleares Asco Vandellos 2 (ANAV) said in a note on its website Saturday that it had found a leak and decided to keep the reactor offline.
"During an inspection, a small leak was detected in a thermocouple column. Once the origin was identified, the necessary action was taken, and the plant kept in cold shutdown," ANAV said.
A water leak in the ventilation valve was identified as the source of the initial water leak that caused the plant to close in March.
According to Entso-e's European transparency platform, the reactor will remain offline until April 14, having been initially taken offline on March 2.
The 1.0 GW plant, 72% owned by Endesa and 28% by Iberdrola, was halted as a preventative measure on that date.
The extended outage overlaps with a planned halt for the 1 GW nuclear plant at Almaraz 2, owned by Iberdrola (53%), Endesa (36%) and Gas Natural Fenosa (11%).
The plant was taken offline Sunday for a programmed refueling halt that will last until May 12, according to Entso-e.
As a result of the two reactors being offline, total nuclear supply into the Spanish system is currently 5.1 GW, compared with a normal level of around 7.1 GW when all seven operational plants are online.
Further ahead in the second quarter, Vandellos 2 is scheduled to undergo its own refueling halt, between May 12 and June 18, according to Entso-e data.