After Local Fault Test: Finnish Nuclear Power Plant Olkiluoto 3 Automatically Shuts Down Again

Helsinki, Finland - The new Finnish nuclear power plant Olkiluoto 3 (OL3) has automatically shut down again. It was only on 20 November 2023 that the operator Teollisuuden Voima Oyj (TVO) had to announce that the OL3 nuclear power plant with a gross capacity of 1,720 MW had unexpectedly gone offline.

The reason was a "faulty temperature measurement in the generator's cooling system".

On Wednesday, 29 November 2023, the OL3 nuclear power plant was taken off the grid again, the nuclear power plant shut down automatically at 13:35 after a short-circuit fault test in the turbine plant. The reason for the interruption in power production is still to be investigated further, TVO announced.

During the fault ride-through test, a short-term short circuit occurs in the grid near the power plant, which leads to a voltage drop. As a result of the experiment, however, electricity production at the 1,720 MW Olkiluoto 3 power plant was automatically stopped.

Vattenfall's Ringhals 4 nuclear power plant in Sweden, which has a gross output of 1,170 MW, is also not producing any electricity. The reason for the shutdown is unknown. Together with the shutdown of the Finnish nuclear power plant Olkiluoto 3, the Nordic electricity market was suddenly missing around 3,000 MW (3GW) of nuclear power plant capacity.

Source: IWR Online, 01 Dec 2023