(Montel) Fortum will cut production at its two Loviisa nuclear reactors in Finland by up to 144 MW until 5 August due to high temperatures of sea water used for cooling, it said on Thursday.
It had previously slashed output by a total 249 MW for two hours on Wednesday due to the warm water.
An annual maintenance outage will start at reactor 2 on 5 August as planned, it added.
Last week the operators of the Nordic region’s other reactors told Montel there was no risk of production cuts due to this summer’s persistent warm weather over the region as cooling water temperatures were around or below 20C.
Sea water above 27-28C affect the operation of nuclear reactors, said a spokesman for TVO, the operator of Finland’s Olkiluoto reactors.