Valve failure stops Spain's Asco-2 nuclear plant

MADRID, May 5 (Reuters) - Spain's Asco-2 nuclear power reactor has stopped working due to valve failure, the nuclear security watchdog said on Saturday.

The plant, based in the north of Spain, stopped working at 0036 local time (2236 GMT) in the early hours of Saturday morning and officials are trying to work out the cause and get it reconnected to the grid, the Nuclear Security Council said.

The failure of the valve did not put workers, the public or the environment in any danger, it said. The 1,027 MW reactor, owned by Endesa (ELE.MC) and Iberdrola (IBE.MC) had been reconnected to the grid on Wednesday following a month's stoppage for refuelling. Plants take several days to reach full pressure again after an outage.

Two of Spain's eight nuclear reactors -- Vandellos-2 and Cofrentes -- are starting to be refuelled and are both expected to be out of action for around two months.

The Trillo reactor, which is also just over 1,000 MW, is programmed to close for maintenance from May 25 to June 17.

Nuclear power provides around 20 percent of Spain's electricity.