The trial operation of the EPR reactor at unit 3 of Finland’s Olkiluoto NPP (OL3) will be suspended for more than a month due to loose parts problems with the turbine's superheater, plant owner-operator Teollisuuden Voima Oyj (TVO) has said. The trial operation will resume at the end of July. According to information received from the plant supplier [Areva-Siemens], OL3 EPR's regular electricity generation will start in December 2022 instead of the previously announced September 2022.

In May 2022, loose parts detached from the steam baffles were found on the turbine-side intermediate superheater, requiring inspection and repair measures. According to reports received from the plant supplier, the repair work will last until the end of July. The trial operation programme and electricity production of the plant unit can only be resumed after these repairs. In addition, additional time has been set aside for future tests of the plant and their analysis based on the experience of the previous pilot phase.

The trial operation phase will be completed in December 2022, when the plant unit's regular electricity generation will begin. The OL3 EPR plant supplier consortium constructed the plant under a fixed-price turnkey contract. The consortium of plant suppliers includes AREVA GmbH, AREVA NP SAS and Siemens AG, which are jointly and severally liable for the obligations under the plant supply contract until the end of the plant unit's warranty period. Construction of OL3 began in 2005. Completion of the reactor was originally scheduled for 2009, but the project has faced a series of delays and setbacks.

TVO said: “The impact of the move to start regular electricity generation is being assessed. The plant supplier is obliged to complete the plant unit in accordance with the plant supply and general settlement agreements.”

Image: Olkiluoto NPP, Unit 3 (Courtesy of TVO)