After the final full-power tests, power generation will be suspended for approximately four weeks to inspect the feedwater pumps and restart the unit for the approximately one-month test production phase.
Olkiluoto 3 produces electricity mainly at full power during the month-long phase and covers about 15 percent of Finland’s electricity needs.
Jarmo TanhuaAccording to the CEO of TVO, the interruption caused by the cracks found in the impellers of all four feed water pumps of the plant unit is regrettable.
“This caused a long period of uncertainty for our winter season production. The studies that turned out to be particularly challenging have now been completed, so that, based on them, we can return to performing the last tests in the trial production program and move towards regular electricity production,” he stated.
The investigations showed that the cracks were probably caused by a higher than usual strain on the impellers when the pumps were used during production tests outside the normal operating range. TVO believes that the recurrence of similar damages can be avoided by optimizing the operation and using impellers with larger measurements.
The operator of the plant expects to receive the new impellers, which have a more durable design, at the end of February or the beginning of March. In the current test production program, time has been reserved for both inspection and installation of the impellers.
Aleksi Teivainen – HT
Source: The Nordic Page