Earliest Olkiluoto 3 restart date pushed back

Friday, 9 December 2022

The TVO update said "the investigation into the damage in Olkiluoto 3’s feedwater pumps has proceeded into its final stages", adding that according to the plant supplier consortium Areva-Siemens, uncertainties remain regarding the schedule.

"The more detailed investigation as well as analysis of the root cause continue related to the cracks found in the impellers of the feedwater pumps at Olkiluoto 3's turbine island. Once the investigation is complete, a decision will be made on the start-up of the plant unit. The possible schedule impact will be communicated as soon as the results of the investigation are available. The plant supplier is obligated to complete the plant unit in accordance with the Plant Contract and settlement agreements," TVO added.

On 18 October, TVO announced that damage had been discovered in the internals of the feedwater pumps located in the plant's turbine island during maintenance and inspection work. Ten days later, it said cracks of a few centimetres had been identified in all four of the feedwater pumps.

The feedwater pumps are Olkiluoto 3's largest pumps and are used to pump water from the feedwater tank into the steam generators. TVO said the cracks detected in the pumps have no impact on nuclear safety.

OL3 attained first criticality on 21 December last year and was connected to the grid on 12 March. The EPR, a 1600 MWe pressurised water reactor, was operated at full capacity for the first time in late-September. The Areva-Siemens consortium constructed the OL3 plant under a fixed-price turnkey contract. Construction began in 2005 but there have been various setbacks and delays. Once regular electricity production has started, OL3 will produce about 14% of Finland's total electricity consumption.